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

[Andre Beck]

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

That makes 169907 total BGP routes. This number is what my other iBGP
mesh members (and eventually eBGP speakers) see and display in the
"sh ip bgp summary" output:

---------------------------------------------------------------------------
BGP router identifier 212.111.224.7, local AS number 15372
BGP table version is 192313826, main routing table version 192313826
169895 network entries and 296415 paths using 26471175 bytes of memory
^^^^^^^^^^^^^^^^^^^^^^
53318 BGP path attribute entries using 2772536 bytes of memory
47917 BGP AS-PATH entries using 1185780 bytes of memory
252 BGP community entries using 14022 bytes of memory
1 BGP route-map cache entries using 16 bytes of memory
1 BGP filter-list cache entries using 16 bytes of memory
3 received paths for inbound soft reconfiguration
3 paths received but denied
BGP activity 3186862/3016966 prefixes, 59880780/59584362 paths
             ^^^^^^^^^^^^^^^^^^^^^^^^
[...]
---------------------------------------------------------------------------
BGP router identifier 212.111.224.2, local AS number 15372
BGP table version is 50948384, main routing table version 50948384
169896 network entries using 17159496 bytes of memory
^^^^^^^^^^^^^^^^^^^^^^
262745 path entries using 12611760 bytes of memory
48561 BGP path attribute entries using 2720088 bytes of memory
44078 BGP AS-PATH entries using 1145288 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 33636632 total bytes of memory
Dampening enabled. 0 history paths, 0 dampened paths
BGP activity 3554346/3384449 prefixes, 24172061/23909313 paths, scan interval 60 secs
             ^^^^^^^^^^^^^^^^^^^^^^^^
----------------------------------------------------------------------------

12.2(25)S5 shows a way larger number of network entries for BGP and
a slightly different display of prefix activity. Is this a bug or a
new way of displaying things, and if so, is it documented?

TIA,
Andre.
-- 
                  The _S_anta _C_laus _O_peration
  or "how to turn a complete illusion into a neverending money source"

-> Andre Beck    +++ ABP-RIPE +++    IBH Prof. Dr. Horn GmbH, Dresden <-