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.
In case anyone wants to check on a 6500, you can run: show platform
hardware capacity pfc and then look under L3 Forwarding Resources.
to fix the problem on sup720/rsp720:
Router(config)#mls cef maximum-routes ip 768
This requires a reload to take effect. If you don't recarve the TCAM and
you accidentally hit the maximum number of prefixes, the entire chassis
will go into software forwarding mode and will require a reboot to recover.
IOW, there is no way of avoiding a reload, so best plan as soon as
possible. More info here:
This problem also affects ASR9000 boxes running typhoon line cards which by
default will only set aside 500k slots for ipv4 prefixes. The fix for
these boxes is:
It seems our "gone bad" 6708s may be included in this issue. If you don't have enough spare ports or spare cards, this puts you in a somewhat precarious situation. You need to reload to affect the v4/v6 route storage change, but you might lose some blades in the process.
Yes, a Sup720/PFC3CXL defaults to 512K IPv4 routes, and reconfiguring
the FIB requires a reload. So I've been quietly expecting a somewhat
serious meltdown when we hit 512K
It would probably be a good time to upgrade the memory on my 7206 NPE-G1 as well (512MB). I was going to replace the router but am going to keep it around for the Fall Semester. Anyone know of any good 3rd party memory modules that are equivalent to the MEM-NPE-G1-1GB? I got a quote for the official Cisco ones last summer and it was around $5,000 lol
This problem also affects ASR9000 boxes running typhoon line cards which by default will only set aside 500k slots for ipv4 prefixes. The fix for these boxes is:
I believe you mean "This problem also affects ASR9000 boxes running ...trident... line cards". Please confirm?
Closer to? Internap announces 507K prefixes to me today. Coupled with the
prefixes I carry in iBGP internally, I've been sitting at 511K for quite
some time, and at occasions, exceeded 512K in the last 2 weeks.
The IPv6 table will not be as big as the v4 table even after full
acceptance. Given that most providers will be advertising a single /32 and
then rest will be some /48 routes for multi-homed scenarios.
This will leave v4 and mpls in one big pool, puts v6 to something useful for quite a while and steals all of the multicast space which is not really used on most deployments.
This gives us the following (which is pretty great for IP backbone purposes in dual stack):
#show mls cef maximum-routes
FIB TCAM maximum routes :
Regardless, shouldn't need more than 626K to make it to v6 and we wont need
as many for v6. That was one of the problems that v6 was designed to
address.
Yep, exactly… the problem is the carving suggested by most kills the fact that MPLS and v4 are pooled, which on a larger network is very nice, especially if using 6PE where each v6 route may need an MPLS route too.
