Arnold, we are using 6 bit subnet masks for our Cisco core router in New York. In order to accomadate additional hosts on this ethernet we had to do some complex subnetting and secondary addressing. One of these hosts is our name server. The problem is the IP address of this name server (192.103.63.100) is illegal from Cisco's point of view due to the subnet mask we are using. The work around to the problem was to make a static ARP entry in Cisco's ARP table with the MAC address of the name server so that Cisco would be able to reach the name server. However, by 9.21 upgrade to support BGP4 we have seen that the Cisco 7000 stopped passing traffic to the name server. The .100 happens to be the all zeros broadcast address on the subnet. It seems that 9.21 changes the destination address of any IP broadcast address to 255.255.255.255 where the destinationation address was kept as .100 in the previous Cisco code (Dave or Paul can correct me). We are planning to do some renumbering on Friday in order to solve this problem. Serpil