Re: Talked about this before

[Bruce Pinsky <bep () whack org>]

Forrest W. Christian wrote:
> On Mon, 9 Sep 2002, Pawlukiewicz Jane wrote:
>
>
> > Quick Question, how much memory does the bgp tables actually take. I'm
> > estimating 32 mb in my plan, but I'm worried that's not enough.
>
>
> Two views:
>
> hln-cs1#sh ip bgp summ
> BGP router identifier 206.127.65.1, local AS number 4043
> BGP table version is 132881, main routing table version 132881
> 112575 network entries and 336143 paths using 24365495 bytes of memory
> 60397 BGP path attribute entries using 3624720 bytes of memory
> 53004 BGP AS-PATH entries using 1426946 bytes of memory
> 0 BGP route-map cache entries using 0 bytes of memory
> 20536 BGP filter-list cache entries using 246432 bytes of memory
> Dampening enabled. 96 history paths, 45 dampened paths
> 111752 received paths for inbound soft reconfiguration
> BGP activity 112575/456 prefixes, 336319/176 paths, scan interval 15 secs
>
> That said:
>
> hln-cs1#sh mem
>                 Head    Total(b)     Used(b)     Free(b)   Lowest(b)
> Largest(b)
> Processor   623C83E0   219380768   117525008   101855760   100536360
> 100521172
>       I/O    F500000    11534336     8157292     3377044     3365952
> 3352444
>
> By the time you populate the routing table and/or cef, and do a few other
> things, you probably want at least 256MB.
>
> If you are using something else, YMMV - it all depends on how efficient
> the software is at storing it in memory.

And add to that the below, noting the 20%+ difference between what the process 
holds and what is reported via the bgp commands :

router#sh proc mem
Total: 226435680, Used: 98336472, Free: 128099208
 PID TTY  Allocated      Freed    Holding    Getbufs    Retbufs Process
   0   0      98188       1848    5744500          0          0 *Init*
   0   0        716  473572020        716          0          0 *Sched*
   0   0 1695597520  282572480      48536     182184          0 *Dead*
...
 103   0  394643684 1139584448   91248608      13000          0 BGP Router
...



router#sh ip bgp sum
BGP table version is 45578905, main routing table version 45578905
112990 network entries and 338257 paths using 23363262 bytes of memory
59466 BGP path attribute entries using 3568080 bytes of memory
52666 BGP AS-PATH entries using 1780032 bytes of memory
1 BGP community entries using 24 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 activity 7862100/10119105 prefixes, 24954823/24616566 paths, scan interval 
60 secs

router#sh mem
                Head    Total(b)     Used(b)     Free(b)   Lowest(b)  Largest(b)
Processor   6210DDA0   226435680    98330588   128105092   122426928   124143936
      I/O    F900000     7340032     2345240     4994792     4859760     4994748


FYI, 3660 w/256MB and 3 transit peers with 112K+ routes each.

--
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bep