Yes, such a document could be useful. We're using a prefix-list as shown below. We could use it as a starting-point to establish a standard prefix filter, or as Randy put it, a prefix filter technical coding advice. ip prefix-list sanity seq 5 deny 0.0.0.0/0 ip prefix-list sanity seq 10 deny 10.0.0.0/8 le 32 ip prefix-list sanity seq 15 deny 127.0.0.0/8 le 32 ip prefix-list sanity seq 20 deny 172.16.0.0/12 le 32 ip prefix-list sanity seq 25 deny 192.0.2.0/24 le 32 ip prefix-list sanity seq 30 deny 192.168.0.0/16 le 32 ip prefix-list sanity seq 35 deny 169.254.0.0/16 le 32 ip prefix-list sanity seq 40 permit 0.0.0.0/0 le 32 /Rosenbecker -- Fredrik Rosenbecker IP-Only AB On 27-Jun-00 philip bridge wrote:
Seeing this mail, together with the cyclic discussions on NANOG about prefix filters and 'does anyone know if Provider X is filtering prefixes from block Y at mask Z' type problems, got me thinking that it might be a good idea for the RIPE community to come up with a set of recommendations for BGP prefix filters. It would have a number of advantages.
- a standard prefix filter recommendation would always be in synch with Registry practices. - it would lower the effort barrier for people to implement prefix filtering in the first place, and therefore foster stability of the global routing system. - it would at least help to align the filtering practices of Providers a little bit, so that debugging routing problems becomes a little bit less like guesswork... hopefully fewer threads like 'does anyone know if Provider X is filtering prefixes from block Y at mask Z?'
I am thinking of something broadly along the lines of RIPE-210 for route dampening.
Feedback?
Phil
At 17:32 21.06.00 +0200, Joao Luis Silva Damas wrote:
During the RIPE 36 meeting in Budapest there was a request to publish the list of CIDR blocks allocated by the RIPE NCC and the smallest allocation issued from each of them.
This is it:
62/8: /19 193/8: /29 # Contain small PI assignments 194/8: /29 # Contain small PI assignments 195/8: /29 # Contain small PI assignments 212/8: /19 213/8: /19 217/8: /20
We shall put this information permanently on our website.
regards,
Joao Damas Head of External Services RIPE NCC
Philip Bridge Nextra (Schweiz) AG <www.nextra.ch> Tel: +41 031 985 88 06 / Mobile: +41 79 659 75 50 E-Mail: <mailto:bridge@nextra.ch> Disclaimer: <http://www.nextra.ch/signature_nw.html>