[6bone] Cisco IOS Experiences

[Bernhard Schmidt]

On Fri, Jan 31, 2003 at 09:25:02AM +0100, Marcel Lemmen wrote:

> Does anyone has experiences with these IOS'es in a production environment
> (good and bad please)? Please let me know if there were any problem, how
> this has been solved etc. I need to convince the management this IOS is
> good enough to use :)

We are running 12.2T since about 12.2(4)T on two 7206VXR located at INXS
and DECIX (public exchange points) since about nine months. The first
version were very buggy, e.g. broken unicast IPv4 BGP when enabling
multicast IPv4 BGP, broken OSPF, sudden reloads up to 12.2(11)T2 when
deleting a tunnel interface, 99%/100% cpu for hours until reloading
after running fine for a couple of weeks, and so on. 12.2(13)T runs okay
right now, while we have problems on one machine mixing up IPv6 headers
when forwarding packets through a tunnel. But since this problem did not
appear on any other of our routers we think it might be a hardware
problem.

We also have 12.2(13)T running on two 7507 in the core network. These
machines mixed up routing for one special host after reloading (while
the rest of the network the host was running in was routed okay, and the
host did _not_ have a /32 route, neither in the IP routing table nor in
the dCEF table). The problem could be fixed by clearing the OSPF process.
The rest of the problems is rather cosmetic, e.g. one of the 7500s does
not appear in the IPv6 traceroute definitely going through this router
on one day, then appears on another, then disappears and so on. Also,
you should note that if you want to use the only available decent IPv6
IGP (IS-IS) with tunnels you have to use GRE tunnels, which currently do
not use IPv6 (d)CEF. A 7500 doing 100Mbps of IPv4 has about 10% cpu
load, doing additional 5Mbps of IPv6 with ipv6ip tunnels increased to
load to about 15% while using GRE tunnels the CPU load increased to more
than 40%! So you should not use GRE tunnels on heavy loaded systems if
possible.

At this time I would wait for 12.2S which was sheduled for January,
27th, so we hope it will be there soon.

-- 
   bye bye
     Bernhard