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Re: Talked about this before

  • From: Bruce Pinsky
  • Date: Mon Sep 09 22:20:29 2002 
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