I haven't seen anyone bring up this point yet, but I feel like I'm missing something... I receive a full BGP table from several providers. They send me ~490k *prefixes* each. However, my router shows ~332k *subnets* in the routing table. As I understand it, the BGP table contains duplicate information (for example a supernet is announced as well as all subnets within that supernet) or excess information (prefix is announced as two /17's instead of a single /16) and can otherwise be summarized to save space in the RIB. It appears to me that the weekly CIDR report shows similar numbers: Recent Table History Date Prefixes CIDR Agg 30-05-14 502889 283047 31-05-14 502961 283069 01-06-14 502836 283134 02-06-14 502943 283080 03-06-14 502793 283382 04-06-14 503177 282897 05-06-14 503436 283062 06-06-14 503988 282999 In this case, does the 512k limit of the 6500/7600 refer to the RIB or the FIB? And does it even matter since the BGP prefix table can automatically be reduced to ~300k routes? Thanks, --Blake Drew Weaver wrote the following on 5/6/2014 10:39 AM:
Hi all,
I am wondering if maybe we should make some kind of concerted effort to remind folks about the IPv4 routing table inching closer and closer to the 512K route mark.
We are at about 94/95% right now of 512K.
For most of us, the 512K route mark is arbitrary but for a lot of folks who may still be running 6500/7600 or other routers which are by default configured to crash and burn after 512K routes; it may be a valuable public service.
Even if you don't have this scenario in your network today; chances are you connect to someone who connects to someone who connects to someone (etc...) that does.
In case anyone wants to check on a 6500, you can run: show platform hardware capacity pfc and then look under L3 Forwarding Resources.
Just something to think about before it becomes a story the community talks about for the next decade.
-Drew