The IPv4 Internet Hiccups

New submitter pla writes: Due to a new set of routes published yesterday, the internet has effectively undergone a schism. All routers with a TCAM allocation of 512k (or less), in particular Cisco Catalyst 6500 and 7600's, have started randomly forgetting portions of the internet. 'Cisco also warned its customers in May that this BGP problem was coming and that, in particular, a number of routers and networking products would be affected. There are workarounds, and, of course the equipment could have been replaced. But, in all too many cases this was not done. ... Unfortunately, we can expect more hiccups on the Internet as ISPs continue to deal with the BGP problem." Is it time to switch to all IPv6 yet?

Yes, Please

[jfdavis668]

We changed all our systems over time to handle this great IPv6 change, and haven't used IPv6 yet. Our service provider doesn't even offer it. Come on, some of us are more than ready. We will probably have failures, because it hasn't been truly tested, but we are far more ready than we were for Y2K.

Not really to do with "BGP" or "IPv4" as such...

[cardpuncher]

This isn't really to do with BGP or IPv4 as such, it's an inherent problem in the way "The Internet" regards addresses.

You might be able to get some efficiencies in IPv6 by incorporating formerly-unrelated address allocations under a single prefix. But that doesn't solve the problem of a continuously growing network, increasingly complex (and commercially controversial) peering arrangements, the fact that IPv6 addresses are actually larger and the fact that you're going to have to support IPv4 anyway in parallel with any IPv6 transition (I don't personally believe it will ever happen, but that's a different story).

You could, however, get rather more efficiency in core routing tables if network addresses only had a very transient existence and were related to the source/destination route to be employed (eg: look up a domain name, do some route pre-computation, allocate some addressing tokens that make sense to the routers on the path, recalculate the route periodically or in response to packet loss). That's not IPv6, though. IPv6 has the same order of dependence on every router knowing about every destination network as IPv4 does (give or take the slightly greater prefixing efficiency).

TL;DR - The Internet is getting bigger. Buy more kit.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:Stop doing CIDR!

[BaronM]

OK, I've done BGP before, and I've never heard of anything smaller than a /24 being globally advertised -- most common router configurations won't even accept anything smaller.

That said, how is any network of any size supposed to protect itself again ISP outages other than multihoming? It clutters the routing table, but there is no other solution.