- routing-wg - mailman.ripe.net

RIPE-181 to RPSL Migration; Completed switch-over to phase 2
by DB-News 14 May '01

14 May '01

Dear Colleagues, (Apologies for multiple messages). This is to announce that we have completed the phase 1 of migration. Starting from today, Monday, 14th May, 2001, <auto-dbm(a)ripe.net> shall only accept updates in RPSL format; updates in RIPE-181 format will no longer be accepted. Updates in RIPE-181 format can be sent to <auto-181(a)ripe.net>, where they will be automatically converted to RPSL format. <auto-rpsl(a)ripe.net> will continue to accept updates in RPSL format. The update path for the TEST database has also been changed. In summary, from 14th May, 2001: =============================== RIPE Database: ------------- <auto-dbm(a)ripe.net> - updates in RPSL format only <auto-rpsl(a)ripe.net> - updates in RPSL format only <auto-181(a)ripe.net> - updates in RIPE-181 format, automatically converted to RPSL format TEST Database: ------------- <test-dbm(a)ripe.net> - updates in RPSL format only <test-rpsl(a)ripe.net> - updates in RPSL format only <test-181(a)ripe.net> - updates in RIPE-181 format, automatically converted to RPSL format Please note that from Monday, 15th October, 2001, updates in RIPE-181 format will no longer be accepted by the RIPE Database. Further information is available from http://www.ripe.net/rpsl/. If you have any questions, please contact <ripe-dbm(a)ripe.net>. Regards, Engin Gunduz ____________________________ RIPE Database Administration.

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Weekly Routing Table Report
by Routing Analysis 10 May '01

10 May '01

This is an automated weekly mailing describing the state of the Internet Routing Table as seen from APNIC's router in Japan. Daily listings are sent to bgp-stats(a)lists.apnic.net For a graphical representation, please see http://www.apnic.net/stats/bgp. If you have any comments please contact Philip Smith <pfs(a)cisco.com>. Routing Table Report 11 May, 2001 Analysis Summary ---------------- BGP routing table entries examined: 105792 Origin ASes present in the Internet Routing Table: 10804 Origin ASes announcing only one prefix: 3935 Transit ASes present in the Internet Routing Table: 1445 Average AS path length visible in the Internet Routing Table: 5.3 Max AS path length visible: 16 Illegal AS announcements present in the Routing Table: 16 Non-routable prefixes present in the Routing Table: 0 Prefixes being announced from the IANA Reserved Address blocks: 1 Number of addresses announced to Internet: 1263460384 Equivalent to 75 /8s, 78 /16s and 224 /24s Percentage of available address space announced: 34.1 Percentage of allocated address space announced: 65.7 Percentage of available address space allocated: 51.9 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 15441 Prefixes being announced from the APNIC address blocks: 14012 APNIC Region origin ASes present in the Internet Routing Table: 1249 APNIC Region origin ASes announcing only one prefix: 445 APNIC Region transit ASes present in the Internet Routing Table: 209 Average APNIC Region AS path length visible: 5.1 Max APNIC Region AS path length visible: 16 Number of APNIC addresses announced to Internet: 70917987 Equivalent to 4 /8s, 58 /16s and 31 /24s Percentage of available APNIC address space announced: 69.7 APNIC AS Blocks 4608 - 4864, 7467 - 7722, 9216 - 10239, 17408 - 18431 APNIC Address Blocks 61/8, 202/7, 210/7 and 218/8 ARIN Region Analysis Summary ---------------------------- Prefixes being announced by ARIN Region ASes: 73634 Prefixes being announced from the ARIN address blocks: 50662 ARIN Region origin ASes present in the Internet Routing Table: 6580 ARIN Region origin ASes announcing only one prefix: 1970 ARIN Region transit ASes present in the Internet Routing Table: 691 Average ARIN Region AS path length visible: 5.2 Max ARIN Region AS path length visible: 13 Number of ARIN addresses announced to Internet: 183888365 Equivalent to 10 /8s, 245 /16s and 233 /24s Percentage of available ARIN address space announced: 84.3 ARIN AS Blocks 1 - 1876, 1902 - 2042, 2044 - 2046, 2048 - 2106 2138 - 2584, 2615 - 2772, 2823 - 2829, 2880 - 3153 3354 - 4607, 4865 - 5119, 5632 - 6655, 6912 - 7466 7723 - 8191, 10240 - 12287, 13312 - 15359 16384 - 17407, 18432 - 20479 ARIN Address Blocks 63/8, 64/7, 66/8, 199/8, 200/8, 204/6, 208/7 and 216/8 RIPE Region Analysis Summary ---------------------------- Prefixes being announced by RIPE Region ASes: 16701 Prefixes being announced from the RIPE address blocks: 13038 RIPE Region origin ASes present in the Internet Routing Table: 2972 RIPE Region origin ASes announcing only one prefix: 1516 RIPE Region transit ASes present in the Internet Routing Table: 544 Average RIPE Region AS path length visible: 5.9 Max RIPE Region AS path length visible: 15 Number of RIPE addresses announced to Internet: 114898378 Equivalent to 6 /8s, 217 /16s and 53 /24s Percentage of available RIPE address space announced: 76.1 RIPE AS Blocks 1877 - 1901, 2042, 2047, 2107 - 2136, 2585 - 2614 2773 - 2822, 2830 - 2879, 3154 - 3353, 5377 - 5631 6656 - 6911, 8192 - 9215, 12288 - 13311, 15360 - 16383 20480 - 21503 RIPE Address Blocks 62/8, 80/7, 193/8, 194/7, 212/7 and 217/8 APNIC Region per AS prefix count summary ---------------------------------------- ASN No of nets /19 equiv Description 1221 1766 707 Telstra 2764 430 147 connect.com.au pty ltd 703 381 205 UUNET Technologies, Inc. 2907 363 883 SINET Japan 4755 328 112 VSNL India 4538 243 1049 China Education and Research 7539 209 90 Delegated to TWNIC for subseq 7657 206 14 The Internet Group Limited 7474 193 86 Optus Communications 4134 192 632 Data Communications Bureau 7545 154 10 TPG Internet Pty Ltd 17561 152 69 Internet service provision to 1237 148 50 System Engineering Research I 4766 147 598 KORnet Powered BY Korea Telec 4740 140 10 Ozemail 4786 126 7 NetConnect Communications Pty 9443 125 23 INTERNETPRIMUS-AS-A 7586 123 9 Paradox Digital Pty. Ltd 9394 122 19 CHINA RAILWAY TELECOMMUNICATI 4736 120 17 Magna Data RIPE Region per AS prefix count summary --------------------------------------- ASN No of nets /19 equiv Description 702 543 803 UUNET Technologies, Inc. 15870 446 3 Global Center Frankfurt 3301 390 401 TeliaNet Sweden 1257 278 263 Swipnet AB 1270 266 440 UUNET Germany 3215 213 224 RAIN 680 212 938 Deutschef Forschurgsnetz 5515 193 336 Sonera Finland 719 187 146 LANLINK 786 185 952 JANET IP Service 3320 162 710 Deutsche Telekom AG 517 131 137 Xlink 5400 129 33 Concert Internet Plus Europea 8708 127 7 Romania Data System 3303 122 296 Swisscom 2856 120 396 BTnet UK Regional network 1290 102 204 PSINet UK Ltd. 1267 100 978 IUnet S.p.A 1901 92 77 EUnet Austria 1849 91 79 UUNET UK (formerly PIPEX) ARIN Region per AS prefix count summary --------------------------------------- ASN No of nets /19 equiv Description 701 2381 3908 UUNET Technologies, Inc. 705 1143 54 UUNET Technologies, Inc. 7018 1019 3283 AT&T 1 955 4464 BBN Planet 7046 802 565 UUNET Technologies, Inc. 3491 694 181 CAIS Internet 1239 635 1606 Sprint ICM-Inria 2914 598 1185 Verio, Inc. 3561 544 1215 Cable & Wireless USA 3549 507 524 Global Crossing 4293 501 52 Cable & Wireless USA 18994 493 5 Global Crossing 690 463 54 Merit Network 209 459 726 Qwest 2548 410 506 Digital Express Group, Inc. 174 405 2695 PSINet Inc. 3908 384 233 Supernet, Inc. 3602 358 73 Sprint Canada 3967 340 228 Exodus Communication 4323 340 136 Time Warner Communications, I Global Per AS prefix count summary ---------------------------------- ASN No of nets /19 equiv Description 701 2381 3908 UUNET Technologies, Inc. 1221 1766 707 Telstra 705 1143 54 UUNET Technologies, Inc. 7018 1019 3283 AT&T 1 955 4464 BBN Planet 7046 802 565 UUNET Technologies, Inc. 3491 694 181 CAIS Internet 1239 635 1606 Sprint ICM-Inria 2914 598 1185 Verio, Inc. 3561 544 1215 Cable & Wireless USA 702 543 803 UUNET Technologies, Inc. 3549 507 524 Global Crossing 4293 501 52 Cable & Wireless USA 18994 493 5 Global Crossing 690 463 54 Merit Network 209 459 726 Qwest 15870 446 3 Global Center Frankfurt 2764 430 147 connect.com.au pty ltd 2548 410 506 Digital Express Group, Inc. 174 405 2695 PSINet Inc. List of Unregistered ASNs (Global) ---------------------------------- Bad AS Designation Network Transit AS Description 60002 RESERVED 64.76.148.0/24 19583 CHILE S.A. 2027 UNALLOCATED 150.185.128.0/18 8143 Publicom Corp. 1877 UNALLOCATED 192.108.196.0/24 1800 SPRINT 1877 UNALLOCATED 192.108.209.0/24 1880 Stupi, house man's 1877 UNALLOCATED 192.108.210.0/24 1880 Stupi, house man's 1877 UNALLOCATED 192.108.214.0/24 1800 SPRINT 5757 UNALLOCATED 192.239.13.0/24 701 UUNET Technologies, 60002 RESERVED 200.9.98.0/24 6429 RdC Internet 60002 RESERVED 200.9.99.0/24 6429 RdC Internet 17441 UNALLOCATED 203.131.192.0/24 6347 SAVVIS Communication 65502 PRIVATE 203.166.83.0/24 10084 Western Australian I 65500 PRIVATE 203.166.86.0/24 10084 Western Australian I 5555 UNALLOCATED 205.110.64.0/24 721 DLA Systems Automati 5555 UNALLOCATED 205.110.68.0/22 721 DLA Systems Automati 5555 UNALLOCATED 205.110.72.0/21 721 DLA Systems Automati 5757 UNALLOCATED 207.19.224.0/24 701 UUNET Technologies, Advertised IANA Reserved Addresses ---------------------------------- Network Origin AS Description 201.115.100.0/24 7018 AT&T Number of prefixes announced per prefix length (Global) ------------------------------------------------------- /1:0 /2:0 /3:0 /4:0 /5:0 /6:0 /7:0 /8:22 /9:5 /10:6 /11:9 /12:30 /13:74 /14:205 /15:341 /16:6943 /17:1151 /18:2133 /19:6648 /20:5186 /21:4524 /22:6813 /23:8728 /24:60541 /25:313 /26:512 /27:432 /28:450 /29:377 /30:286 /31:1 /32:62 Number of /24s announced per /8 block (Global) ---------------------------------------------- 9:3 12:364 13:10 15:1 17:2 24:689 26:1 32:12 38:593 44:3 47:1 53:2 55:1 57:11 61:30 62:122 63:1946 64:1613 65:527 66:315 128:35 129:111 130:23 131:36 132:9 133:1 134:169 135:11 136:16 137:121 138:247 139:49 140:141 141:166 142:61 143:41 144:136 145:9 146:136 147:135 148:96 149:123 150:27 151:300 152:700 153:36 154:17 155:78 156:43 157:107 158:172 159:76 160:27 161:56 162:62 163:134 164:96 165:126 166:178 167:138 168:79 169:34 170:264 171:2 192:5446 193:1957 194:2074 195:783 196:398 198:3650 199:3392 200:2020 201:1 202:2458 203:4810 204:3378 205:2253 206:2837 207:2904 208:2981 209:3138 210:503 211:155 212:873 213:403 214:9 215:12 216:3015 217:221 End of report

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RIPE-181 to RPSL Migration; Phase 2.
by DB-News 10 May '01

10 May '01

Dear Colleagues, (Apologies for multiple messages). On and from Monday, 14th May, 2001, <auto-dbm(a)ripe.net> shall only accept updates in RPSL format; updates in RIPE-181 format will no longer be accepted. Updates in RIPE-181 format can be sent to <auto-181(a)ripe.net>, where they will be automatically converted to RPSL format. <auto-rpsl(a)ripe.net> will continue to accept updates in RPSL format. The update path for the TEST database will also be changed. In summary, from 14th May, 2001: =============================== RIPE Database: - ------------- <auto-dbm(a)ripe.net> - updates in RPSL format only <auto-rpsl(a)ripe.net> - updates in RPSL format only <auto-181(a)ripe.net> - updates in RIPE-181 format, automatically converted to RP S L format TEST Database: - ------------- <test-dbm(a)ripe.net> - updates in RPSL format only <test-rpsl(a)ripe.net> - updates in RPSL format only <test-181(a)ripe.net> - updates in RIPE-181 format, automatically converted to RP S L format On Monday, 14th May, 2001, we cannot guarantee that an update message sent to <auto-dbm(a)ripe.net> will use a specific update path (RPSL or RIPE-181). Thus, we advise that updates in RIPE-181 format should be sent to <auto-181(a)ripe.net> and that updates in RPSL format should be sent to <auto-rpsl(a)ripe.net>. Please note that from Monday, 15th October, 2001, updates in RIPE-181 format will no longer be accepted by the RIPE Database. Further information is available from http://www.ripe.net/rpsl/. If you have any questions, please contact <ripe-dbm(a)ripe.net>. Regards, A. M. R. Magee - -------------- Database Group RIPE NCC

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RIPE-181 to RPSL Migration; Phase 2.
by db-news＠ripe.net 10 May '01

10 May '01

Dear Colleagues, (Apologies for multiple messages). On and from Monday, 14th May, 2001, <auto-dbm(a)ripe.net> shall only accept updates in RPSL format; updates in RIPE-181 format will no longer be accepted. Updates in RIPE-181 format can be sent to <auto-181(a)ripe.net>, where they will be automatically converted to RPSL format. <auto-rpsl(a)ripe.net> will continue to accept updates in RPSL format. The update path for the TEST database will also be changed. In summary, from 14th May, 2001: =============================== RIPE Database: ------------- <auto-dbm(a)ripe.net> - updates in RPSL format only <auto-rpsl(a)ripe.net> - updates in RPSL format only <auto-181(a)ripe.net> - updates in RIPE-181 format, automatically converted to RPS L format TEST Database: ------------- <test-dbm(a)ripe.net> - updates in RPSL format only <test-rpsl(a)ripe.net> - updates in RPSL format only <test-181(a)ripe.net> - updates in RIPE-181 format, automatically converted to RPS L format On Monday, 14th May, 2001, we cannot guarantee that an update message sent to <auto-dbm(a)ripe.net> will use a specific update path (RPSL or RIPE-181). Thus, we advise that updates in RIPE-181 format should be sent to <auto-181(a)ripe.net> and that updates in RPSL format should be sent to <auto-rpsl(a)ripe.net>. Please note that from Monday, 15th October, 2001, updates in RIPE-181 format will no longer be accepted by the RIPE Database. Further information is available from http://www.ripe.net/rpsl/. If you have any questions, please contact <ripe-dbm(a)ripe.net>. Regards, A. M. R. Magee -------------- Database Group RIPE NCC

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The Cidr Report
by Tony Bates 05 May '01

05 May '01

This is an auto-generated mail on Fri May 4 23:00:00 PDT 2001 It is not checked before it leaves my workstation. However, hopefully you will find this report interesting and will take the time to look through this to see if you can improve the amount of aggregation you perform. The report is split into sections: 0) General Status List the route table history for the last week, list any possibly bogus routes seen and give some status on ASes. 1) Gains by aggregating at the origin AS level This lists the "Top 30" players who if they decided to aggregate their announced classful prefixes at the origin AS level could make a significant difference in the reduction of the current size of the Internet routing table. This calculation does not take into account the inclusion of holes when forming an aggregate so it is possible even larger reduction should be possible. 2) Weekly Delta A summary of the last weeks changes in terms of withdrawn and added routes. Please note that this is only a snapshot but does give some indication of ASes participating in CIDR. Clearly, it is generally a good thing to see a large amont of withdrawls. 3) Interesting aggregates Interesting here means not an aggregate made as a set of classful routes. Thanks to xara.net for giving me access to their routing tables once a day. Please send any comments about this report directly to me. Check http://www.employees.org/~tbates/cidr-report.html for a daily update of this report. ------------------------------------------------------------------------------ CIDR REPORT for 04May01 0) General Status Table History ------------- Date Prefixes 270401 100797 280401 102051 290401 102329 300401 102763 010501 103252 020501 104027 030501 104798 040501 104512 Check http://www.employees.org/~tbates/cidr.plot.html for a plot of the table history. Possible Bogus Routes --------------------- *** Bogus 218.6.128.0/17 from AS4134 AS Summary ---------- Number of ASes in routing system: 10668 Number of ASes announcing only one prefix: 6344 (3599 cidr, 2745 classful) Largest number of cidr routes: 2588 announced by AS2149 Largest number of classful routes: 1404 announced by AS701 1) Gains by aggregating at the origin AS level --- 04May01 --- ASnum NetsNow NetsCIDR NetGain % Gain Description AS1221 1396 1034 362 25.9% TELSTRA-AS AS701 1404 1217 187 13.3% Alternet AS2149 613 452 161 26.3% PSINET-2 AS705 380 250 130 34.2% part of AS assignment AS701 - AS7 AS4151 258 146 112 43.4% part of AS assignment AS4151 - AS AS4293 392 283 109 27.8% part of AS assignment AS4287 - AS AS6429 215 107 108 50.2% ATT LA Internet Chile AS6595 164 62 102 62.2% autonomous system number assigned AS13999 104 8 96 92.3% autonomous system number assigned AS4755 235 145 90 38.3% part of AS assignment AS4608 - AS AS8013 343 258 85 24.8% autonomous system number assigned AS7018 701 617 84 12.0% AT&T WorldNet Service Backbone AS577 236 167 69 29.2% autonomous system number assigned AS174 427 361 66 15.5% Performance Systems International AS6471 113 49 64 56.6% autonomous system number assigned AS5106 100 37 63 63.0% autonomous system number assigned AS3464 153 91 62 40.5% Alabama Research and Education Ne AS3749 119 58 61 51.3% autonomous system number assigned AS3602 254 195 59 23.2% Sprint Canada Inc. AS724 205 147 58 28.3% part of AS assignment AS721 - AS7 AS11252 91 33 58 63.7% autonomous system number assigned AS1 609 551 58 9.5% GTE Internetworking AS16758 63 6 57 90.5% autonomous system number assigned AS6413 67 11 56 83.6% autonomous system number assigned AS226 149 93 56 37.6% Los Nettos AS4323 232 179 53 22.8% Time Warner Telecom Internet AS17561 110 59 51 46.4% UNKNOWN AS852 206 157 49 23.8% autonomous system number assigned AS8151 183 137 46 25.1% autonomous system number assigned AS13544 68 22 46 67.6% autonomous system number assigned For the rest of the previous weeks gain information please see http://www.employees.org:80/~tbates/cidr-report.html 2) Weekly Delta Please see http://www.employees.org:80/~tbates/cidr-report.html for this part of the report 3) Interesting aggregates Please see http://www.employees.org:80/~tbates/cidr-report.html for this part of the report

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Weekly Routing Table Report
by Routing Analysis 03 May '01

03 May '01

This is an automated weekly mailing describing the state of the Internet Routing Table as seen from APNIC's router in Japan. Daily listings are sent to bgp-stats(a)lists.apnic.net For a graphical representation, please see http://www.apnic.net/stats/bgp. If you have any comments please contact Philip Smith <pfs(a)cisco.com>. Routing Table Report 04 May, 2001 Analysis Summary ---------------- BGP routing table entries examined: 103810 Origin ASes present in the Internet Routing Table: 10703 Origin ASes announcing only one prefix: 3895 Transit ASes present in the Internet Routing Table: 1444 Average AS path length visible in the Internet Routing Table: 5.3 Max AS path length visible: 15 Illegal AS announcements present in the Routing Table: 15 Non-routable prefixes present in the Routing Table: 0 Prefixes being announced from the IANA Reserved Address blocks: 1 Number of addresses announced to Internet: 1246077232 Equivalent to 74 /8s, 69 /16s and 161 /24s Percentage of available address space announced: 33.6 Percentage of allocated address space announced: 64.8 Percentage of available address space allocated: 51.9 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 15211 Prefixes being announced from the APNIC address blocks: 13775 APNIC Region origin ASes present in the Internet Routing Table: 1213 APNIC Region origin ASes announcing only one prefix: 437 APNIC Region transit ASes present in the Internet Routing Table: 206 Average APNIC Region AS path length visible: 5.1 Max APNIC Region AS path length visible: 15 Number of APNIC addresses announced to Internet: 70563339 Equivalent to 4 /8s, 52 /16s and 182 /24s Percentage of available APNIC address space announced: 69.4 APNIC AS Blocks 4608 - 4864, 7467 - 7722, 9216 - 10239, 17408 - 18431 APNIC Address Blocks 61/8, 202/7, 210/7 and 218/8 ARIN Region Analysis Summary ---------------------------- Prefixes being announced by ARIN Region ASes: 71945 Prefixes being announced from the ARIN address blocks: 49729 ARIN Region origin ASes present in the Internet Routing Table: 6532 ARIN Region origin ASes announcing only one prefix: 1948 ARIN Region transit ASes present in the Internet Routing Table: 691 Average ARIN Region AS path length visible: 5.2 Max ARIN Region AS path length visible: 14 Number of ARIN addresses announced to Internet: 186557918 Equivalent to 11 /8s, 30 /16s and 165 /24s Percentage of available ARIN address space announced: 85.5 ARIN AS Blocks 1 - 1876, 1902 - 2042, 2044 - 2046, 2048 - 2106 2138 - 2584, 2615 - 2772, 2823 - 2829, 2880 - 3153 3354 - 4607, 4865 - 5119, 5632 - 6655, 6912 - 7466 7723 - 8191, 10240 - 12287, 13312 - 15359 16384 - 17407, 18432 - 20479 ARIN Address Blocks 63/8, 64/7, 66/8, 199/8, 200/8, 204/6, 208/7 and 216/8 RIPE Region Analysis Summary ---------------------------- Prefixes being announced by RIPE Region ASes: 16639 Prefixes being announced from the RIPE address blocks: 12919 RIPE Region origin ASes present in the Internet Routing Table: 2956 RIPE Region origin ASes announcing only one prefix: 1508 RIPE Region transit ASes present in the Internet Routing Table: 546 Average RIPE Region AS path length visible: 5.9 Max RIPE Region AS path length visible: 15 Number of RIPE addresses announced to Internet: 97641033 Equivalent to 5 /8s, 209 /16s and 226 /24s Percentage of available RIPE address space announced: 64.7 RIPE AS Blocks 1877 - 1901, 2042, 2047, 2107 - 2136, 2585 - 2614 2773 - 2822, 2830 - 2879, 3154 - 3353, 5377 - 5631 6656 - 6911, 8192 - 9215, 12288 - 13311, 15360 - 16383 20480 - 21503 RIPE Address Blocks 62/8, 80/7, 193/8, 194/7, 212/7 and 217/8 APNIC Region per AS prefix count summary ---------------------------------------- ASN No of nets /19 equiv Description 1221 1789 700 Telstra 2764 432 147 connect.com.au pty ltd 703 385 204 UUNET Technologies, Inc. 2907 361 875 SINET Japan 4755 315 110 VSNL India 4538 243 1056 China Education and Research 7539 213 97 Delegated to TWNIC for subseq 4134 194 632 Data Communications Bureau 7474 190 85 Optus Communications 7657 180 13 The Internet Group Limited 1237 154 70 System Engineering Research I 7545 153 10 TPG Internet Pty Ltd 17561 151 61 Internet service provision to 4740 150 10 Ozemail 4766 146 597 KORnet Powered BY Korea Telec 4786 128 7 NetConnect Communications Pty 9394 122 19 CHINA RAILWAY TELECOMMUNICATI 9443 122 22 INTERNETPRIMUS-AS-A 7586 121 9 Paradox Digital Pty. Ltd 7617 121 46 One.Net Pty Ltd RIPE Region per AS prefix count summary --------------------------------------- ASN No of nets /19 equiv Description 702 540 801 UUNET Technologies, Inc. 15870 458 3 Global Center Frankfurt 3301 390 401 TeliaNet Sweden 1257 278 263 Swipnet AB 1270 265 440 UUNET Germany 680 213 946 Deutschef Forschurgsnetz 3215 209 221 RAIN 5515 190 336 Sonera Finland 719 189 146 LANLINK 786 185 952 JANET IP Service 3320 161 710 Deutsche Telekom AG 517 129 136 Xlink 5400 128 33 Concert Internet Plus Europea 3303 122 296 Swisscom 2856 121 396 BTnet UK Regional network 8708 121 7 Romania Data System 1290 102 204 PSINet UK Ltd. 1267 100 978 IUnet S.p.A 1901 92 77 EUnet Austria 1849 89 79 UUNET UK (formerly PIPEX) ARIN Region per AS prefix count summary --------------------------------------- ASN No of nets /19 equiv Description 701 2342 4448 UUNET Technologies, Inc. 705 1138 54 UUNET Technologies, Inc. 7018 980 3233 AT&T 1 958 4464 BBN Planet 7046 798 564 UUNET Technologies, Inc. 1239 626 1605 Sprint ICM-Inria 2914 598 1187 Verio, Inc. 3561 545 1224 Cable & Wireless USA 18994 524 6 Crossing 3549 501 515 Global Crossing 4293 475 51 Cable & Wireless USA 209 447 718 Qwest 174 428 2696 PSINet Inc. 2548 407 506 Digital Express Group, Inc. 690 391 49 Merit Network 8151 366 228 UniNet S.A. de C.V. 3908 354 268 Supernet, Inc. 3602 346 72 Sprint Canada 3967 339 228 Exodus Communication 4323 337 136 Time Warner Communications, I Global Per AS prefix count summary ---------------------------------- ASN No of nets /19 equiv Description 701 2342 4448 UUNET Technologies, Inc. 1221 1789 700 Telstra 705 1138 54 UUNET Technologies, Inc. 7018 980 3233 AT&T 1 958 4464 BBN Planet 7046 798 564 UUNET Technologies, Inc. 1239 626 1605 Sprint ICM-Inria 2914 598 1187 Verio, Inc. 3561 545 1224 Cable & Wireless USA 702 540 801 UUNET Technologies, Inc. 18994 524 6 Crossing 3549 501 515 Global Crossing 4293 475 51 Cable & Wireless USA 15870 458 3 Global Center Frankfurt 209 447 718 Qwest 2764 432 147 connect.com.au pty ltd 174 428 2696 PSINet Inc. 2548 407 506 Digital Express Group, Inc. 690 391 49 Merit Network 3301 390 401 TeliaNet Sweden List of Unregistered ASNs (Global) ---------------------------------- Bad AS Designation Network Transit AS Description 60002 RESERVED 64.76.148.0/24 19583 CHILE S.A. 2027 UNALLOCATED 150.185.128.0/18 8143 Publicom Corp. 1877 UNALLOCATED 192.108.196.0/24 1800 SPRINT 1877 UNALLOCATED 192.108.209.0/24 1880 Stupi, house man's 1877 UNALLOCATED 192.108.210.0/24 1880 Stupi, house man's 1877 UNALLOCATED 192.108.214.0/24 1800 SPRINT 5757 UNALLOCATED 192.239.13.0/24 701 UUNET Technologies, 60002 RESERVED 200.9.98.0/24 6429 RdC Internet 60002 RESERVED 200.9.99.0/24 6429 RdC Internet 65535 PRIVATE 203.24.169.0/24 17486 Swiftel Communicatio 65500 PRIVATE 203.166.86.0/24 10084 Western Australian I 5555 UNALLOCATED 205.110.64.0/24 721 DLA Systems Automati 5555 UNALLOCATED 205.110.68.0/22 721 DLA Systems Automati 5555 UNALLOCATED 205.110.72.0/21 721 DLA Systems Automati 5757 UNALLOCATED 207.19.224.0/24 701 UUNET Technologies, Advertised IANA Reserved Addresses ---------------------------------- Network Origin AS Description 201.115.100.0/24 7018 AT&T Number of prefixes announced per prefix length (Global) ------------------------------------------------------- /1:0 /2:0 /3:0 /4:0 /5:0 /6:0 /7:0 /8:22 /9:4 /10:5 /11:10 /12:29 /13:71 /14:203 /15:333 /16:6925 /17:1145 /18:2113 /19:6618 /20:5147 /21:4456 /22:6752 /23:8628 /24:59263 /25:274 /26:441 /27:361 /28:378 /29:323 /30:246 /31:1 /32:62 Number of /24s announced per /8 block (Global) ---------------------------------------------- 4:1 9:3 12:351 13:10 15:1 17:2 24:681 26:1 32:12 38:7 44:3 47:1 53:2 55:1 57:10 61:29 62:123 63:1914 64:1527 65:478 66:315 128:36 129:117 130:21 131:25 132:9 133:1 134:166 135:11 136:17 137:120 138:246 139:49 140:140 141:164 142:60 143:41 144:131 145:9 146:132 147:134 148:170 149:125 150:28 151:300 152:726 153:34 154:17 155:78 156:41 157:107 158:171 159:76 160:27 161:58 162:61 163:134 164:81 165:129 166:178 167:134 168:81 169:34 170:261 171:2 192:5384 193:1965 194:2075 195:779 196:401 198:3618 199:3377 200:1991 201:1 202:2418 203:4788 204:3342 205:2242 206:2766 207:2842 208:2950 209:3125 210:492 211:151 212:827 213:386 214:9 215:11 216:2966 217:203 End of report

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The Cidr Report
by Tony Bates 28 Apr '01

28 Apr '01

This is an auto-generated mail on Fri Apr 27 23:00:00 PDT 2001 It is not checked before it leaves my workstation. However, hopefully you will find this report interesting and will take the time to look through this to see if you can improve the amount of aggregation you perform. The report is split into sections: 0) General Status List the route table history for the last week, list any possibly bogus routes seen and give some status on ASes. 1) Gains by aggregating at the origin AS level This lists the "Top 30" players who if they decided to aggregate their announced classful prefixes at the origin AS level could make a significant difference in the reduction of the current size of the Internet routing table. This calculation does not take into account the inclusion of holes when forming an aggregate so it is possible even larger reduction should be possible. 2) Weekly Delta A summary of the last weeks changes in terms of withdrawn and added routes. Please note that this is only a snapshot but does give some indication of ASes participating in CIDR. Clearly, it is generally a good thing to see a large amont of withdrawls. 3) Interesting aggregates Interesting here means not an aggregate made as a set of classful routes. Thanks to xara.net for giving me access to their routing tables once a day. Please send any comments about this report directly to me. Check http://www.employees.org/~tbates/cidr-report.html for a daily update of this report. ------------------------------------------------------------------------------ CIDR REPORT for 27Apr01 0) General Status Table History ------------- Date Prefixes 200401 100216 210401 100108 220401 100099 230401 100219 240401 100457 250401 100635 260401 100755 270401 100797 Check http://www.employees.org/~tbates/cidr.plot.html for a plot of the table history. Possible Bogus Routes --------------------- *** Bogus 218.6.128.0/17 from AS4134 AS Summary ---------- Number of ASes in routing system: 10591 Number of ASes announcing only one prefix: 6292 (3570 cidr, 2722 classful) Largest number of cidr routes: 1365 announced by AS705 Largest number of classful routes: 1602 announced by AS1221 1) Gains by aggregating at the origin AS level --- 27Apr01 --- ASnum NetsNow NetsCIDR NetGain % Gain Description AS1221 1602 1190 412 25.7% TELSTRA-AS AS701 1409 1222 187 13.3% Alternet AS705 393 258 135 34.4% part of AS assignment AS701 - AS7 AS4151 257 145 112 43.6% part of AS assignment AS4151 - AS AS6429 216 105 111 51.4% ATT LA Internet Chile AS6595 163 62 101 62.0% autonomous system number assigned AS13999 104 8 96 92.3% autonomous system number assigned AS4293 372 279 93 25.0% part of AS assignment AS4287 - AS AS8013 326 239 87 26.7% autonomous system number assigned AS7018 698 613 85 12.2% AT&T WorldNet Service Backbone AS4755 229 144 85 37.1% part of AS assignment AS4608 - AS AS15412 260 183 77 29.6% FLAG Telecom Global Internet AS AS577 238 169 69 29.0% autonomous system number assigned AS6471 113 49 64 56.6% autonomous system number assigned AS5106 101 37 64 63.4% autonomous system number assigned AS3464 153 91 62 40.5% Alabama Research and Education Ne AS3749 120 59 61 50.8% autonomous system number assigned AS724 202 144 58 28.7% part of AS assignment AS721 - AS7 AS3602 253 195 58 22.9% Sprint Canada Inc. AS11252 92 34 58 63.0% autonomous system number assigned AS16758 63 6 57 90.5% autonomous system number assigned AS1 608 551 57 9.4% GTE Internetworking AS6413 67 11 56 83.6% autonomous system number assigned AS226 149 93 56 37.6% Los Nettos AS4323 232 179 53 22.8% Time Warner Telecom Internet AS852 203 155 48 23.6% autonomous system number assigned AS9269 109 62 47 43.1% Hong Kong CTI AS855 145 99 46 31.7% part of AS assignment AS853 - AS1 AS13544 68 22 46 67.6% autonomous system number assigned AS12235 49 3 46 93.9% Cove Software Systems Inc For the rest of the previous weeks gain information please see http://www.employees.org:80/~tbates/cidr-report.html 2) Weekly Delta Please see http://www.employees.org:80/~tbates/cidr-report.html for this part of the report 3) Interesting aggregates Please see http://www.employees.org:80/~tbates/cidr-report.html for this part of the report

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Weekly Routing Table Report
by Routing Analysis 26 Apr '01

26 Apr '01

This is an automated weekly mailing describing the state of the Internet Routing Table as seen from APNIC's router in Japan. Daily listings are sent to bgp-stats(a)lists.apnic.net For a graphical representation, please see http://www.apnic.net/stats/bgp. If you have any comments please contact Philip Smith <pfs(a)cisco.com>. Routing Table Report 27 Apr, 2001 Analysis Summary ---------------- BGP routing table entries examined: 104638 Origin ASes present in the Internet Routing Table: 10673 Origin ASes announcing only one prefix: 3885 Transit ASes present in the Internet Routing Table: 1436 Average AS path length visible in the Internet Routing Table: 5.3 Max AS path length visible: 21 Illegal AS announcements present in the Routing Table: 19 Non-routable prefixes present in the Routing Table: 0 Prefixes being announced from the IANA Reserved Address blocks: 1 Number of addresses announced to Internet: 1223206251 Equivalent to 72 /8s, 232 /16s and 165 /24s Percentage of available address space announced: 33.0 Percentage of allocated address space announced: 63.6 Percentage of available address space allocated: 51.9 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 15702 Prefixes being announced from the APNIC address blocks: 14207 APNIC Region origin ASes present in the Internet Routing Table: 1233 APNIC Region origin ASes announcing only one prefix: 441 APNIC Region transit ASes present in the Internet Routing Table: 199 Average APNIC Region AS path length visible: 5.1 Max APNIC Region AS path length visible: 21 Number of APNIC addresses announced to Internet: 71044162 Equivalent to 4 /8s, 60 /16s and 12 /24s Percentage of available APNIC address space announced: 69.8 APNIC AS Blocks 4608 - 4864, 7467 - 7722, 9216 - 10239, 17408 - 18431 APNIC Address Blocks 61/8, 202/7, 210/7 and 218/8 ARIN Region Analysis Summary ---------------------------- Prefixes being announced by ARIN Region ASes: 72658 Prefixes being announced from the ARIN address blocks: 49910 ARIN Region origin ASes present in the Internet Routing Table: 6488 ARIN Region origin ASes announcing only one prefix: 1937 ARIN Region transit ASes present in the Internet Routing Table: 688 Average ARIN Region AS path length visible: 5.2 Max ARIN Region AS path length visible: 14 Number of ARIN addresses announced to Internet: 181209106 Equivalent to 10 /8s, 205 /16s and 8 /24s Percentage of available ARIN address space announced: 83.1 ARIN AS Blocks 1 - 1876, 1902 - 2042, 2044 - 2046, 2048 - 2106 2138 - 2584, 2615 - 2772, 2823 - 2829, 2880 - 3153 3354 - 4607, 4865 - 5119, 5632 - 6655, 6912 - 7466 7723 - 8191, 10240 - 12287, 13312 - 15359 16384 - 17407, 18432 - 20479 ARIN Address Blocks 63/8, 64/7, 66/8, 199/8, 200/8, 204/6, 208/7 and 216/8 RIPE Region Analysis Summary ---------------------------- Prefixes being announced by RIPE Region ASes: 16259 Prefixes being announced from the RIPE address blocks: 12958 RIPE Region origin ASes present in the Internet Routing Table: 2951 RIPE Region origin ASes announcing only one prefix: 1505 RIPE Region transit ASes present in the Internet Routing Table: 549 Average RIPE Region AS path length visible: 5.9 Max RIPE Region AS path length visible: 15 Number of RIPE addresses announced to Internet: 96959193 Equivalent to 5 /8s, 199 /16s and 122 /24s Percentage of available RIPE address space announced: 64.2 RIPE AS Blocks 1877 - 1901, 2042, 2047, 2107 - 2136, 2585 - 2614 2773 - 2822, 2830 - 2879, 3154 - 3353, 5377 - 5631 6656 - 6911, 8192 - 9215, 12288 - 13311, 15360 - 16383 20480 - 21503 RIPE Address Blocks 62/8, 80/7, 193/8, 194/7, 212/7 and 217/8 APNIC Region per AS prefix count summary ---------------------------------------- ASN No of nets /19 equiv Description 1221 2010 692 Telstra 2764 428 139 connect.com.au pty ltd 703 390 205 UUNET Technologies, Inc. 2907 363 875 SINET Japan 4755 317 111 VSNL India 7539 219 101 Delegated to TWNIC for subseq 4134 194 631 Data Communications Bureau 4766 186 766 KORnet Powered BY Korea Telec 7474 184 85 Optus Communications 4538 183 989 China Education and Research 7657 173 13 The Internet Group Limited 9269 161 22 Hong Kong CTI 1237 156 70 System Engineering Research I 4740 153 10 Ozemail 17561 151 61 Internet service provision to 7545 146 10 TPG Internet Pty Ltd 4786 128 7 NetConnect Communications Pty 7586 125 10 Paradox Digital Pty. Ltd 7617 124 46 One.Net Pty Ltd 9443 122 22 INTERNETPRIMUS-AS-A RIPE Region per AS prefix count summary --------------------------------------- ASN No of nets /19 equiv Description 702 538 649 UUNET Technologies, Inc. 3301 389 337 TeliaNet Sweden 1257 278 263 Swipnet AB 1270 276 448 UUNET Germany 680 211 938 Deutschef Forschurgsnetz 3215 211 228 RAIN 5515 191 336 Sonera Finland 719 189 146 LANLINK 786 180 935 JANET IP Service 3320 161 710 Deutsche Telekom AG 5400 128 40 Concert Internet Plus Europea 517 127 134 Xlink 3303 124 298 Swisscom 2856 122 388 BTnet UK Regional network 8708 118 5 Romania Data System 1290 116 206 PSINet UK Ltd. 1849 105 223 UUNET UK (formerly PIPEX) 1267 101 978 IUnet S.p.A 1901 97 77 EUnet Austria 3269 85 277 TELECOM ITALIA ARIN Region per AS prefix count summary --------------------------------------- ASN No of nets /19 equiv Description 701 2367 3732 UUNET Technologies, Inc. 705 1752 73 UUNET Technologies, Inc. 7018 963 3159 AT&T 1 962 4472 BBN Planet 7046 773 553 UUNET Technologies, Inc. 1239 631 1581 Sprint ICM-Inria 2914 604 1202 Verio, Inc. 3561 562 1249 Cable & Wireless USA 18994 525 6 Crossing 3549 499 515 Global Crossing 174 475 2755 PSINet Inc. 4293 475 51 Cable & Wireless USA 209 450 715 Qwest 690 445 44 Merit Network 2548 402 514 Digital Express Group, Inc. 3908 375 262 Supernet, Inc. 8151 365 226 UniNet S.A. de C.V. 3602 345 72 Sprint Canada 3967 337 226 Exodus Communication 4323 337 136 Time Warner Communications, I Global Per AS prefix count summary ---------------------------------- ASN No of nets /19 equiv Description 701 2367 3732 UUNET Technologies, Inc. 1221 2010 692 Telstra 705 1752 73 UUNET Technologies, Inc. 7018 963 3159 AT&T 1 962 4472 BBN Planet 7046 773 553 UUNET Technologies, Inc. 1239 631 1581 Sprint ICM-Inria 2914 604 1202 Verio, Inc. 3561 562 1249 Cable & Wireless USA 702 538 649 UUNET Technologies, Inc. 18994 525 6 Crossing 3549 499 515 Global Crossing 174 475 2755 PSINet Inc. 4293 475 51 Cable & Wireless USA 209 450 715 Qwest 690 445 44 Merit Network 2764 428 139 connect.com.au pty ltd 2548 402 514 Digital Express Group, Inc. 703 390 205 UUNET Technologies, Inc. 3301 389 337 TeliaNet Sweden List of Unregistered ASNs (Global) ---------------------------------- Bad AS Designation Network Transit AS Description 60002 RESERVED 64.76.148.0/24 19583 CHILE S.A. 2027 UNALLOCATED 150.185.128.0/18 8143 Publicom Corp. 64842 PRIVATE 164.159.151.0/24 19143 Fish and Wildlife Se 64842 PRIVATE 164.159.152.0/22 19143 Fish and Wildlife Se 64842 PRIVATE 164.159.159.0/24 19143 Fish and Wildlife Se 64842 PRIVATE 164.159.160.0/24 19143 Fish and Wildlife Se 1877 UNALLOCATED 192.108.196.0/24 1800 SPRINT 1877 UNALLOCATED 192.108.209.0/24 1880 Stupi, house man's 1877 UNALLOCATED 192.108.210.0/24 1880 Stupi, house man's 1877 UNALLOCATED 192.108.214.0/24 1800 SPRINT 5757 UNALLOCATED 192.239.13.0/24 701 UUNET Technologies, 60002 RESERVED 200.9.98.0/24 6429 RdC Internet 60002 RESERVED 200.9.99.0/24 6429 RdC Internet 65535 PRIVATE 203.24.169.0/24 17486 Swiftel Communicatio 65500 PRIVATE 203.166.86.0/24 10084 Western Australian I 5555 UNALLOCATED 205.110.64.0/24 721 DLA Systems Automati 5555 UNALLOCATED 205.110.68.0/22 721 DLA Systems Automati 5555 UNALLOCATED 205.110.72.0/21 721 DLA Systems Automati 5757 UNALLOCATED 207.19.224.0/24 701 UUNET Technologies, Advertised IANA Reserved Addresses ---------------------------------- Network Origin AS Description 201.115.100.0/24 7018 AT&T Number of prefixes announced per prefix length (Global) ------------------------------------------------------- /1:0 /2:0 /3:0 /4:0 /5:0 /6:0 /7:0 /8:21 /9:4 /10:4 /11:10 /12:29 /13:67 /14:204 /15:331 /16:6936 /17:1138 /18:2101 /19:6595 /20:5104 /21:4438 /22:6747 /23:8662 /24:60408 /25:288 /26:463 /27:294 /28:296 /29:227 /30:193 /31:1 /32:77 Number of /24s announced per /8 block (Global) ---------------------------------------------- 9:3 12:353 13:10 15:1 17:2 24:682 26:1 32:23 38:7 44:3 47:1 53:2 55:1 57:11 61:28 62:133 63:1939 64:1473 65:1069 66:310 128:35 129:114 130:22 131:26 132:9 133:1 134:166 135:9 136:16 137:119 138:250 139:62 140:143 141:163 142:60 143:41 144:132 145:9 146:133 147:134 148:142 149:123 150:28 151:301 152:792 153:33 154:17 155:81 156:40 157:108 158:173 159:84 160:28 161:58 162:61 163:135 164:87 165:124 166:176 167:133 168:85 169:33 170:256 171:2 192:5381 193:1974 194:2079 195:810 196:407 198:3667 199:3403 200:1974 201:1 202:2484 203:5033 204:3379 205:2243 206:2705 207:2914 208:2930 209:3178 210:504 211:150 212:838 213:382 214:9 215:11 216:2944 217:212 End of report

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The status of the migration iissues
by Andrei Robachevsky 26 Apr '01

26 Apr '01

Dear Colleagues, As some of you might have noticed, several problems showed up after the migration. Let me present an update on their status: 1. PGP signed messages sent to <auto-rpsl(a)ripe.net> didn't pass authorization checks This was fixed on 24th of April. Please note that PGP signed updates cannot be processed by <auto-dbm(a)ripe.net>. Until 14th of May, <auto-dbm(a)ripe.net> processes updates in RIPE-181 format and automatically translates them into RPSL, which voids PGP signatures. 2. Conversion problems of updates sent to <auto-dbm(a)ripe.net> Problematic objects were: - Objects with syntax errors - Indented objects (containing leading whitespace) In both cases objects were not converted to RPSL and user received an empty acknowledgement. This was fixed today, 26th of April. Please note that <auto-dbm(a)ripe.net> cannot reproduce all the behaviour of the v2 database. In particular, empty attribute is treated as a syntax error and Routing Policy System Security authorization rules apply. We strongly recommend you to switch to updates in RPSL format as soon as possible. Also note, that <auto-dbm(a)ripe.net> will process updates in RIPE-181 format until 14th of May. After that, updates in RIPE-181 format should be sent to the new address, <auto-181(a)ripe.net>, and <auto-dbm(a)ripe.net> will accept only RPSL syntax. 3. Due to above problems some of the updates were not processed. If you haven't received an acknowledgement from the database one day after you sent your update we would kindly ask to re-send it. We apologize for any inconvenience these problems caused. We are working on some minor problems and rely on your understanding. Please visit the "Migration Issues" link on the "Database Status" page (http://www.ripe.net/ripencc/pub-services/db/issues.html) for the up-to-date information. Regards, Andrei Robachevsky DB Group Manager RIPE NCC

3 2

Draft revision of RIPE-210: Coordinated Route Flap Damping Parameters
by Philip Smith 25 Apr '01

25 Apr '01

Hi, bcc: nanog, apops, APNIC routing SIG, afnog Please accept my apologies for any duplicates. The attached is a proposed update and revision of the RIPE-210 Coordinated Route Flap Damping Parameters document. The authors would welcome any comments and feedback regarding the content of this document, either to the RIPE Routing Working Group, or at the RIPE meeting in Bologna, Italy, on w/b 30th April. We would also welcome links/sample configurations/examples for other router platforms (specifically Juniper/Foundry/Extreme and any other platforms which may be found in today's Internet) to augment the Cisco IOS configuration examples given in the Appendix. thanks, and kind regards, philip -- >>>>begin RIPE Routing-WG Recommendation for coordinated route-flap damping parameters Philip Smith Daniel Karrenberg Christian Panigl Joachim Schmitz This document Obsoletes: ripe-210, ripe-178 ----------------------------------------------------------------- Document status Version 1.2, April 24th, 2001 Abstract This paper recommends a set of route-flap damping parameters which should be applied by all ISPs in the Internet and should be deployed as default values by BGP router vendors. Table of Contents 1. Introduction 1.1 Motivation for route-flap damping 1.2 What is route-flap damping ? 1.3 "Progressive" versus "flat&gentle" approach 1.4 Motivation for coordinated parameters 1.5 Aggregation versus damping 1.6 "Golden Networks" 2. Recommended damping parameters 2.1 Motivation for recommendation 2.2 Description of recommended damping parameters 2.3 Example configuration for Cisco IOS 3. Other Features contributing to Internet Stability 3.1 BGP Route Refresh 3.2 Soft Reconfiguration (Cisco IOS) 3.3 Fast-External-Fallover (Cisco IOS) 4. Potential problems 4.1 Multiplication of flaps between ASes with multiple interconnections 4.2 Non-recommended flap damping parameters 5. References 6. Acknowledgements Appendices A.1 "Golden Networks" A.2 Sample Cisco IOS Configuration A.3 Study of Flap Damping Operation 1. Introduction Route-flap damping is a mechanism for (BGP) routers which is aimed at improving the overall stability of the Internet routing table and reducing the load on the CPUs of the core routers. 1.1 Motivation for route-flap damping In the early 1990s the accelerating growth in the number of prefixes being announced to the Internet (often due to inadequate prefix-aggregation), the denser meshing through multiple inter-provider paths, and increased instabilities started to cause significant impact on the performance and efficiency of the Internet backbone routers. Every time a routing prefix becomes unreachable because of a single line-flap, the withdrawal has to be advertised to the whole core Internet and dealt with by every single router which is carrying the full Internet routing table. To overcome this situation a route-flap damping mechanism was invented in 1993 and has been integrated into several router software implementations since 1995 (for example, Cisco, Merit/RSd, GateD Consortium). The implementation is described in detail in RFC2439. The flap damping mechanism is now widely used to help keep severe instabilities under control and more localised in the Internet. And there is a second benefit: it is raising the awareness of the existence of instabilities because severe route/line-flapping problems lead to permanent suppression of the unstable area by means of holding down the flapping prefixes. Route-flap damping has its greatest and most consistent value if it is applied as near to the source of the problem as possible. Therefore flap-damping should be applied both at peering and upstream boundaries, as well as at customer boundaries (see 1.4 and 1.5 for details). 1.2 What is route-flap damping ? When BGP route-flap damping is enabled in a router the router starts to collect statistics about the announcement and withdrawal of prefixes. Route-flap damping is governed by a set of parameters with vendor-supplied default values which may be modified by the router manager. The names, semantic and syntax of these parameters differ between the various implementations; however, the behaviour of the damping mechanism is basically the same. Each time a prefix is withdrawn, the router will increment the damping penalty by a fixed amount. When the number of withdrawals/announcements (=flap) is exceeded in a given time frame (cutoff threshold) the path is no longer used and not advertised to any BGP neighbour for a predetermined period starting from when the prefix stops flapping. Any more flaps happening after the prefix enters suppressed state will attract additional penalty. Once the prefix stops flapping, the penalty is decremented over time using a half-life parameter until the penalty is below a reuse threshold. Once below this reuse threshold the suppressed path is then re-used and re-advertised to BGP neighbours. Pointers to some more detailed and vendor specific documents: Cisco BGP Case Studies: Route Flap Damping http://www.cisco.com/warp/public/459/16.html ISI/RSd Configuration: Route Flap Damping http://www.isi.edu/div7/ra/RSd/doc/dampen.html GateD Configuration: Weighted Route Damping Statement http://www.gated.org/gated-web/code/doc/manuals/config_guide/bgp/ weighted_route_dampening.html See also "5. References" 1.3 "Progressive" versus "flat&gentle" approach One easy approach would be to just apply the current default-parameters which are treating all prefixes equally ("flat&gentle") everywhere. However, there is a major concern to penalise longer prefixes (=smaller aggregates) more than well aggregated short prefixes ("progressive"), because the number of short prefixes in the routing table is significantly lower and it seems in general that those are tending to be more stable and also are tending to affect more users. Another aspect is that progressive damping might increase the awareness of aggregation needs. However, it has to be accompanied by a careful design which doesn't force a rush to request and assign more address space than needed. A significant number of important services is sitting in long prefixes (e.g. root name servers), so the progressive approach has to exclude the strong penalisation for these so-called "golden" prefixes. With this recommendation we are trying to make a compromise and it is therefore called "graded damping". 1.4 Motivation for coordinated parameters There is a strong need for the coordinated use of damping parameters for several reasons: Coordination of "progressiveness": If penalties are not coordinated throughout the Internet, route-flap damping could lead to additional flapping or inconsistent routing because longer prefixes might already be re-announced through some parts of the Internet where shorter prefixes are still held down through other paths. Coordination of hold-down and reuse-threshold parameters between ISPs: If an upstream or peering provider would be damping more aggressively (e.g. triggered by less flaps or applying longer hold-down timers) than an access-provider towards his customers it will lead to a very inconsistent situation, where a flapping network might still be able to reach "near-line" parts of the Internet. Debugging of such instabilities is then much harder because the effect for the customer leads to the assumption that there is a problem "somewhere" in the "upstream" Internet instead of making him just call his ISPs hot-line and complain that he can't get out any longer. Further, after successful repair of the problem the access-provider can easily clear the flap-damping for his customer on his local router instead of needing to contact upstream NOCs all over the Internet to get the damping cleared. Vendor Defaults: As with most software implementations, there need to be some default values set when route-flap damping is enabled on routers. Vendors choosing different default values will result in a similar situation to that described above, where the more aggressive values will result in "black spots" in the Internet. Coordinated values will ensure consistency in dealing with instabilities. 1.5 Aggregation versus damping If a customer of an ISP is only using Provider Aggregated addresses, the aggregating upstream provider doesn't need to apply damping on these prefixes towards his customer, because instabilities of such prefixes will not propagate into the Internet. However, if a customer insists on announcing prefixes which can't be aggregated by its provider, damping should be applied. Reasons for leaking prefixes might include dual-homing (to different providers) of a customer, or customer's reluctance to renumber into the provider's aggregated address range. 1.6 "Golden Networks" Even though damping is strongly recommended, in some cases it may make sense to exclude certain networks or even individual hosts from damping. This is especially true if damping would cut off the access to vital infrastructure elements of the Internet. A most prominent example are the root name servers. At least in principle, there should be enough redundancy for root name servers. However we are still facing a situation where, at least outside USA, large parts of the Internet are seeing all of them through the same one or two backbone/upstream links (sea cable) and any instability of those links which is triggering damping would unnecessarily prolong the inaccessibility of the root name servers for an hour (at least those sitting in a /24 or longer prefix). Other examples of inclusions in the "Golden Networks" might be the Global Top Level Domain (gTLD) name servers, and possibly overseas or "special" networks the local ISP wishes to have continued connectivity to regardless of the instability of the infrastructure inbetween. Appendix 1 gives an example of the Golden Networks at the time of publication of this document. Before implementation of route flap damping using these Golden Networks, network managers are strongly encouraged to check that the networks listed are indeed still being announced, and are home to the servers mentioned. This can be done by matching BGP table announcements with the published addresses for the listed servers. These exceptions must only be made if there are strong and identifiable needs for them - the rule should be to apply coordinated route flap damping throughout. 2. Recommended damping parameters 2.1 Motivation for recommendation At RIPE26 and 27 Christian Panigl presented the following network backbone maintenance example from his own experience, which was triggering flap damping in some upstream and peering ISPs routers for all his and his customers /24 prefixes for more than 3 hours because of too "aggressive" parameters: scheduled SW upgrade of backbone router failed: - reload after SW upgrade 1 flap - new SW crashed 1 flap - reload with old SW 1 flap ------ 3 flaps within 10 minutes which resulted in the following damping scenario at some boundaries with progressive route-flap damping enabled: Prefix length: /24 /19 /16 suppress time: ~3h 45-60' <30' Therefore, in the Routing-WG session at RIPE27, it was agreed that suppression should not start until the 4th flap in a row and that the maximum suppression should in no case last longer than 1 hour from the last flap. It was agreed that a recommendation from RIPE would be desirable. Given that the current allocation policies are expected to hold for the foreseeable future, it was suggested that all /19's or shorter prefixes are not penalised harder (longer) than current Cisco default damping does. More recently, this recommendation has been altered so that only prefixes longer than a /21 are now damped more aggresively. The registries' minimum allocation is currently a /20, and a /21 announcement is quite feasible for a multihoming situation. With these suggestions in mind, Tony Barber designed the following set of route-flap damping parameters which have proved to work smoothly in his environment for a couple of months prior to the publication of RIPE-178 (the original version of this document). 2.2 Description of recommended damping parameters Basically the recommended values do the following with harsher treatment for /24 and longer prefixes: * don't start damping until the 4th flap * /24 and longer prefixes: max=min outage 60 minutes * /22 and /23 prefixes: max outage 45 minutes; min outage of 30 minutes * all other prefix lengths: max outage 30 minutes; min outage 10 minutes If a specific damping implementation does not allow configuration of prefix-dependent parameters the least aggressive set should be used: * don't start damping before the 4th flap in a row * max outage 30 minutes; min outage 10 minutes A sample configuration for Cisco IOS is provided in Appendix 2. This sample can be used as a basis for a configuration on other router platforms. 3. Other Features contributing to Internet Stability 3.1 BGP Route refresh RFC2918 describes a Route Refresh Capability for BGP-4. Prior to this, there was no mechanism to reset or refresh a BGP peering session without tearing it down and waiting for it to re-establish. This process is destructive - prefixes being exchanged between the two peering routers are withdrawn from their respective ASes, and this withdrawal can potentially pass through the whole Internet causing the burden and increased instability discussed earlier. Usually all that an ISP wishes when reseting a BGP session is to implement new or revised policy - destroying a BGP session carrying a large or the full routing table has severe impact on the ISP and his neighbours on the Internet. Furthermore, reset of a BGP session means the withdrawal of reachability information from the ISP's customers, and they have the perception that the Internet has "vanished" - the impression left with the end-user is that of an unreliable network. Route Refresh implements a messaging system whereby a router wishing to refresh or reset its BGP peering with its neighbour simply has to send the notification. When the neighbour receives the notification, it will send its entire announcement to its peer (obtained from BGP best path table and applicable outbound policy). To find out if your neighbour supports Route Refresh, using Cisco IOS as an example, enter: Router# sho ip bgp neigh w.x.y.c | include refresh Received route refresh capability(new) from peer Route refresh request: received 0, sent 0 If your router and your peer router support Route Refresh, you can use: Router# clear ip bgp w.x.y.c in for requesting a route refresh without clearing the BGP session. For an outbound route refresh without clearing the BGP session use Router# clear ip bgp w.x.y.c out It is recommended that all users of BGP use the route refresh capability when implementing new BGP policy. 3.2 Soft-Reconfiguration (Cisco IOS) Where the neighbour does not support RFC 2918 Route Refresh, there is a functionality in Cisco IOS called "Soft Reconfiguration". This reserves additional memory in the router to store the BGP table exactly as it was received from the peer, prior to any inbound policy being applied. The advantage of this is that the ISP can then change any inbound policy on the router without reseting the BGP session - the router simply uses the "raw" BGP table it has received from its peer. Disadvantage is that this functionality could potentially consume almost twice the amount of memory required for the BGP table heard from the peer. To configure soft-reconfiguration in IOS, simply add the extra line to the BGP peer configuration as below. Soft-reconfiguration is configured on a per-neighbour basis. ! router bgp 65501 neighbor 10.0.0.2 remote-as 65502 neighbor 10.0.0.2 soft-reconfiguration inbound ! Without the keyword "soft" a "clear ip bgp x.x.x.x" will completely reset the BGP session and therefore always withdraw all announced prefixes from/to neighbour x.x.x.x and re-advertise them (= route-flap for all prefixes which are available before and after the clear). With "clear ip bgp x.x.x.x soft out" the router doesn't reset the BGP session itself but sends an update for all its advertised prefixes. With "clear ip bgp x.x.x.x soft in" the router just compares the already received routes (stored in the "received" data structures) from the neighbour against locally configured inbound policy statements. It is recommended to use soft-reconfiguration with all peers which do not support RFC2918 Route Refresh Capability. 3.3 Fast-External-Fallover (Cisco IOS) Cisco IOS by default implements a feature known as "fast-external-fallover". This feature immediately clears the BGP session whenever the line-protocol to the external neighbour goes down. This feature is desirable so that there is fast failover in case of link failures - the router can withdraw paths as soon as the line goes down, rather than waiting for BGP keepalive timers. The drawback of this, however, is that circuits which are prone to unreliability will cause BGP sessions to drop and return (i.e. flap), resulting in instability within the ISP's network, and the potential for flap damping by upstreams or peers. If fast-external-fallover is turned off, the BGP sessions will survive these short line-flaps as it will use the longer BGP keepalive/hold timers (default 60/180 seconds). The drawback of turning it off - and currently it has to be done for a whole router and can not be selected peer-by-peer - is that the switch-over to an alternative path will take longer. We recommend turning off fast-external-fallover whenever possible: ! router bgp 65501 no bgp fast-external-fallover ! Alternatively it might be considered acceptable to retain "fast-external-fallover" and to turn off "interface keepalives" on unreliable circuits to overcome the immediate BGP resets on any significant CRC error period. Another potentially more satisfactory alternative would be to use a shorter per-neighbour BGP keepalive timer which has to be applied on both routers (e.g. 10 seconds which gives a hold-timer of 30 seconds): ! router bgp 65501 neighbor w.x.y.z timers 10 ! 4. Potential problems 4.1 Multiplication of flaps between ASes with multiple interconnections Christian Panigl experienced the following during a circuit upgrade of an Ebone customer: - Only ONE flap was generated as a result of the upgrade process (disconnect router-port from modem A, reconnect to modem B). Nevertheless the customer's prefix was damped in all ICM routers. - The flap statistics in the ICM routers stated *4* flaps !!! - The only explanation would be that the multiple interconnections between Ebone/AS1755 and ICM/AS1800 did multiply the flaps (advertisements/withdrawals arrived time-shifted at ICM routers through the multiple circuits). - This would then potentially hold true for any meshed topology because of the propagation delays of advertisements/withdrawals. There are two potential solutions to workaround this problem. The first one is operational, the second one is a software configuration feature (for Cisco IOS and possibly other implementations as well). * Schedule a downtime for at least 3-5 minutes which should be enough time for the prefix withdrawals to have propagated through all paths before reconnection and re-advertisement of the prefix. Avoid clearing BGP sessions as this also could generate a 30 minute outage through flap damping! * Configure a permanent static route pointing to the customer interface. Even if the interface goes down, there is still an entry in the routing table for the customer network, and BGP will therefore still announce the prefix. Example: ! router bgp 65500 network 169.254.0.0 mask 255.255.0.0 ip route 169.254.0.0 255.255.0.0 serial 5/0 permanent ! If migrating the customer from one router port to another, simply enter the second static route pointing to the new interface. Move the cable between ports - BGP continues to announce the prefix as the entry is still in the routing table. Note: this solution only applies to customers who connect using static routes. If the customer connects using BGP, first disable fast-external-fallover on both the customer and ISP router, and then move the cable in a time period less than the BGP hold-timer. 4.2 Non-recommended flap damping parameters There are situations where service providers would like to design their own route flap damping parameters for local needs or conditions. If this is really desired, then it is important to pay attention to how flap damping parameters are configured, whether the values are feasible or not, etc. For example, in Cisco IOS, it is perfectly possible to configure flap damping parameters which do nothing. * One example might be the configuration "set dampening 15 500 3000 30". Here the reuse limit is 500, maximum suppress time is 30 minutes and the half life is 15 minutes. Using these three parameters gives a maximum possible penalty value of 2000, well below the suppress limit of 3000. So even though this can be successfully configured on the router, no damping will take place. * Another example might be the configuration "set dampening 15 750 3000 30". Here the reuse limit is 750, maximum suppress time is 30 minutes and the half life is 15 minutes. Using these three parameters gives a maximum possible penalty of 3000, exactly the same as the suppress-limit. In Cisco IOS, the penalty is decayed every 5 seconds, so flap damping will only be take place if the update follows the withdraw within that 5 second time frame. 99% of the time no flap damping will take place. 5. References RIPE/Routing-WG Minutes dealing with Route Flap Damping: http://www.ripe.net/ripe/meetings/archive/ripe-24/ripe-m-24.txt http://www.ripe.net/ripe/meetings/archive/ripe-25/ripe-m-25.txt http://www.ripe.net/wg/routing/r25-routing.html http://www.ripe.net/wg/routing/r26-routing.html http://www.ripe.net/wg/routing/r27-routing.html Curtis Villamizar, Ravi Chandra, Ramesh Govindan RFC2439: BGP Route Flap Damping (Proposed Standard) ftp://ftp.ietf.org/rfc/rfc2439.txt Enke Chen RFC2918: Route Refresh Capability for BGP-4 (Proposed Standard) ftp://ftp.ietf.org/rfc/rfc2918.txt Merit/IPMA: Internet Routing Recommendations http://www.merit.edu/ipma/docs/help.html Cisco BGP Case Studies: Route Flap Damping http://www.cisco.com/warp/public/459/16.html Cisco Documentation: Configuring BGP / Route Dampening http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/ 121cgcr/ip_c/ipcprt2/1cdbgp.htm Cisco Documentation: BGP Soft Reset Enhancement http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/ 120newft/120t/120t7/sftrst.htm ISI/RSd Configuration: Route Flap Damping http://www.isi.edu/div7/ra/RSd/doc/dampen.html GateD Configuration: Weighted Route Damping Statement http://www.gated.org/gated-web/code/doc/manuals/config_guide/bgp/ weighted_route_dampening.html 6. Acknowledgements Thanks to all the contributors to this updated version. 7. Changes over previous versions This document is a significant rewrite and update of RIPE-210. The "Golden Networks" have now been moved to an Appendix as they are frequently changing and the authors have come across several instances of providers implementing the recommendations without actually checking that the Root Nameserver networks were still as listed in the document. Updates to the Cisco IOS configuration have been made, and the parameters chosen for /24 networks have been corrected to make them feasible. Examples of flap damping in operation have been added to Appendix 3. The sample configuration has been moved to Appendix 2 - again IOS is used as a known working example. Appendices A.1 "Golden Networks" This appendix lists some examples of Golden Networks which could be used when applying route flap damping at the edge of an ISP's network. The example uses Cisco IOS configuration syntax. The list was correct at time of writing (April 2001). ip prefix-list golden-networks description Golden Networks ! Root Nameservers ip prefix-list golden-networks permit 198.41.0.0/24 ! A & J ip prefix-list golden-networks permit 128.9.0.0/16 ! B ip prefix-list golden-networks permit 192.33.4.0/24 ! C ip prefix-list golden-networks permit 128.8.0.0/16 ! D ip prefix-list golden-networks permit 192.203.230.0/24 ! E ip prefix-list golden-networks permit 192.5.4.0/23 ! F ip prefix-list golden-networks permit 192.112.36.0/24 ! G ip prefix-list golden-networks permit 128.63.0.0/16 ! H ip prefix-list golden-networks permit 192.36.148.0/24 ! I ip prefix-list golden-networks permit 193.0.14.0/24 ! K ip prefix-list golden-networks permit 198.32.64.0/24 ! L ip prefix-list golden-networks permit 202.12.27.0/24 ! M ! Global Top Level Domain Servers ip prefix-list golden-networks permit 192.5.6.0/24 ! A ip prefix-list golden-networks permit 203.181.96.0/19 ! B ip prefix-list golden-networks permit 192.26.92.0/24 ! C ip prefix-list golden-networks permit 192.31.80.0/24 ! D ip prefix-list golden-networks permit 192.12.94.0/24 ! E ip prefix-list golden-networks permit 192.35.51.0/24 ! F ip prefix-list golden-networks permit 192.42.93.0/24 ! G ! ip prefix-list golden-networks permit ???? ! No H ip prefix-list golden-networks permit 192.36.144.0/24 ! I ip prefix-list golden-networks permit 210.132.96.0/19 ! J ip prefix-list golden-networks permit 213.177.192.0/21 ! K ip prefix-list golden-networks permit 192.41.162.0/24 ! L ip prefix-list golden-networks permit 202.153.112.0/20 ! M A.2 Sample Cisco IOS Configuration ! Parameters are : ! set damp <half-life-time> <reuse-at> <suppress-at> <max-suppress-time> ! There is a 1000 penalty for each flap ! There is a 500 penalty for change in attribute ! Penalty decays at granularity of 5 seconds, decay starts as soon as ! prefix is withdrawn ! Unsuppressed at granularity of 10 seconds ! damping info kept until penalty becomes < half of reuse limit. ! ! Cisco/IOS value-ranges: ! ! <half-life-time> (range is 1-45 minutes). ! <reuse-value> (range is 1-20000). ! <suppress-value> (range is 1-20000). ! <max-suppress-time> (range is 1-255 minutes ). ! !----------------------------------------------------------------------- ! ENABLE BGP DAMPenING using "graded" route-map !----------------------------------------------------------------------- router bgp 65500 NO bgp damp bgp damp route-map graded-flap-damping ! !----------------------------------------------------------------------- ! DEFINE "graded" route-map !----------------------------------------------------------------------- NO route-map graded-flap-damping ! ! don't damp Candidate Default Routes ! OPTIONAL (not part of recommendation) ! prefix-list default-networks lists the Candidate Default Routes ! !route-map graded-flap-damping deny 5 ! match ip address prefix-list default-networks ! ! don't damp Golden Networks ! route-map graded-flap-damping deny 10 match ip address prefix-list golden-networks ! ! - /24 and longer prefixes: max=min outage 60 minutes ! route-map graded-flap-damping permit 20 match ip address prefix-list min24 set damp 30 820 3000 60 ! ! - /22 and /23 prefixes: max outage 45 minutes but potential for ! less because of shorter half life value - minimum of 30 minutes ! outage route-map graded-flap-damping permit 30 match ip address prefix-list max22-23 set damp 15 750 3000 45 ! ! - all else prefixes: max outage 30 minutes min outage 10 minutes ! route-map graded-flap-damping permit 40 set damp 10 1500 3000 30 ! !----------------------------------------------------------------------- ! DEFINE PREFIX-LISTS !----------------------------------------------------------------------- ! ! OPTIONAL default-networks !no ip prefix-list default-networks !ip prefix-list default-networks description Candidate Default Routes ! no ip prefix-list golden-networks ip prefix-list golden-networks description Golden Networks ! See 7.1 above for sample list ! no ip prefix-list min24 ip prefix-list min24 description Apply to /24 and longer prefixes ip prefix-list min24 permit 0.0.0.0/0 ge 24 ! no ip prefix-list max22-23 ip prefix-list max22-23 description Apply to /22 and /23 prefixes ip prefix-list max22-23 permit 0.0.0.0/0 ge 22 le 23 ! A.3 Study of Flap Damping Operation It is instructive to observe how route flap damping actually works on a router - doing so will help the reader understand how the particular values described above were chosen. The test bed had two Cisco routers connected to each other. One router originated prefixes, the other one had the flap damping parameters described above in the text. The router originating the prefixes would withdraw a prefix, then reannounce, then withdraw, reannounce, etc. The BGP process in IOS checks every 60 seconds for any new or withdrawn prefixes in the local configuration - so on the source router, the withdraw and announce was done by removing and adding the BGP network statement for the prefix in question. The router monitoring the flaps would see the prefix being withdrawn and then announced 60s later. A.3.1 For /24s Parameters used are "set dampening 15 820 3000 30" 1st flap 1000 decay to 966, 982 at update 2nd flap 1966 decay to 1894, 1926 at update 3rd flap 2894 decay to 2787, 2846 at update 4th flap 3280 decay to 3165, 3226 at update Maximum possible penalty is 3280 as defined by the flap parameters, so the penalty at the 4th flap was only incremented from 2787 to 3280, not 3787 as might have been expected. At the 4th flap the prefix was marked as being suppressed for 59 minutes when the update message was received. If the update after the 4th flap was not received within 4 minutes and 20 seconds, the penalty dropped below 3000, and the prefix was not suppressed. A.3.2 For /22s, /23s Parameters used are "set dampening 15 750 3000 45" 1st flap 1000 decay to 921, 960 at update 2nd flap 1921 decay to 1777, 1850 at update 3rd flap 2777 decay to 2583, 2671 at update 4th flap 3583 decay to 3311, 3451 at update Maximum possible penalty is 6000. At the 4th flap the prefix was marked as being suppressed for 33 minutes when the update message was received. If the update after the 4th flap was not received within 4 minutes and 40 seconds, the penalty dropped below 3000, and the prefix was not suppressed. A.3.3 For remaining prefixes Parameters used are "set dampening 10 1500 3000 30" 1st flap 1000 decay to 889, 946 at update 2nd flap 1889 decay to 1679, 1781 at update 3rd flap 2679 decay to 2367, 2526 at update 4th flap 3367 decay to 3019, 3176 at update Maximum possible penalty is 12000. At the 4th flap the prefix was marked as being suppressed for 10 minutes when the update message was received. If the update after the 4th flap was not received within 2 minutes and 5 seconds, the penalty dropped below 3000, and the prefix was not suppressed. A.3.4 Summary When analysing flap damping performance on the router or across the network, network managers should compare with the above lab tests. Note especially that slowly flapping prefixes are unlikely to be suppressed even though they show significant flapping history. A future version of this document may consider what to do in this instance. >>>>end

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