From list-admin Fri Apr 22 18:19:27 1994

Got a list of routes which are not in the NSFnet table but some other places. Spot that one incident that the aggregate is advertised to both routing tables, but there are few specific routes within the aggregate has been advertised to the NSFNET. So in terms of connectivity, both can reach all the specific routes destination, but the path would be different. However, that cause the difference in size of the routing table. This is just the one I happen to see but there could be more such cases. This indicates reason #1 in my previous message. I also saw a lot of routes in the diff list looks like testnets but not quite sure. I do not have time to do more poking today, I will do it on Monday.

--Jessica

I would agree that the difference in table size is most likely due to CIX issues. I used to see table size differences of a few hundred routes, which I mostly attributed to the few days of lag time in getting new CIX routes registered in the PRDB. ANS-CIX (AS 1957) has a new policy for the past week or two which is to stop automatically registering the CIX-only routes (routes known to the CIX which are not registered by another AS 690 service provider) in the PRDB. I understand they are working out a new policy for getting these CIX-only routes registed in the PRDB. This could account for some of the table size discrepency. Also, as service providers register aggregates in the PRDB, AS 1957 component routes are removed, unless for policy purposes the service provider requests and ANS agrees to leave the AS 1957 component networks configured. This could account for several hundred CIX-only component routes that have recently disappeared from the AS 690 routing tables, but which may still be announced to the CIX. Also, there always seem to be a handful of routes (maybe about 20 ?) which are known to the CIX but which are not registered in the PRDB because they cannot be verified as having been assigned from address space delegated to the InterNIC or RIPE. --Steve Widmayer