[c-nsp] 6500 cef bug?

[Jon Lewis]

Anyone ever seen something like this on the 6509 (sup720-3bxl)?

We have a customer advertising a /24 to the 6509.  The /24 is a subnet of 
a shorter network they use elsewhere on the internet.  It's been working 
fine for quite a while.  The bgp session flaps due to the customer router 
rebooting.  When the session comes back up, the 6509 receives the route. 
sh ip ro <IP> and sh ip bgp <IP> both show exactly what you'd expect. 
But the 6509 isn't actually using the route.  sh ip cef <IP> shows the 
entry for the shorter network out on the internet (not the /24 you'd 
expect).

Clearing the bgp session from either end doesn't help.  I finally 
resolved the issue by installing a static route for the /24 on the 6509 
pointed at the BGP peer IP.  That fixed the show ip cef.  Then I went back 
into the config and removed the static route.  Problem is still resolved.

I used to see vaguely similar things on the 7500 platform...but in that 
case, the fix was to flip dcef off/on.  I suppose in this case, we're 
probably long overdue for a reboot/software upgrade.  Still running 
12.2(18)SXD7b.  I'll probably go to one of the 122-33.SXI versions.

----------------------------------------------------------------------
  Jon Lewis, MCP :)           |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
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