[c-nsp] 12.2(25)S5 shows 190000 BGP prefixes?

[Bruce Pinsky]

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Andre Beck wrote:
> Hi,
> 
> I just found that a 72xx running 12.2(25)S5 shows an increased number
> of active BGP prefixes. Compared to the other iBGP mesh members, the
> number from "sh ip bgp summary" is way too large:
> 
> ----------------------------------------------------------------------------
> BGP router identifier 212.111.224.8, local AS number 15372
> BGP table version is 12935683, main routing table version 12935683
> 190844 network entries using 21565372 bytes of memory
> ^^^^^^^^^^^^^^^^^^^^^^
> 302705 path entries using 15740660 bytes of memory
> 57469/31045 BGP path/bestpath attribute entries using 6206652 bytes of memory
> 51832 BGP AS-PATH entries using 1384316 bytes of memory
> 1009 BGP community entries using 39244 bytes of memory
> 0 BGP route-map cache entries using 0 bytes of memory
> 42054 BGP filter-list cache entries using 504648 bytes of memory
> BGP using 45440892 total bytes of memory
> BGP activity 190845/0 prefixes, 4608899/4306191 paths, scan interval 60 secs
>              ^^^^^^
> Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
> 212.111.224.2   4 15372   84994 3335308 12935678    0    0 8w3d            2
> 212.111.224.7   4 15372 4116825 3335309 12935678    0    0 8w3d       135105
> 213.148.131.181 4 20676 6778241  169985 12935683    1    0 8w3d       167596
> ----------------------------------------------------------------------------
> 
> Using "sh ip route summary", the real amount of BGP routes comes out
> at a more reasonable count:
> 
> Route Source    Networks    Subnets     Overhead    Memory (bytes)
> bgp 15372       110058      59849       10874048    26063524
>   External: 127676 Internal: 42231 Local: 0
> 


Info from "show ip route summary" is displaying the number of BGP routes in
the forwarding RIB, i.e. installed in the routing table.  The output of
"show ip bgp summary" is showing you the count of the number of network
entries across all of your BGP peers in the BGP adacency RIB structures.
That would explain the difference between the counts.

What versions are running on your other BGP routers that you included?  I'd
be curious to do a quick test to see if I can duplicate your results.

I know there were changes in 12.2(25)S in several areas of code that
contribute to the output of "show ip bgp summary".  I suppose there could
be a bug that was introduced as a result of some of those changes.

I'd probably open a case at this point.

- --
=========
bep

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