BGP memory

Unanswered Question
Sep 12th, 2007


I have few question regarding BGP memory consupmtion.

when I issue show ip bgp summary

229747 network entries using 25961411 bytes of memory

351053 path entries using 16850544 bytes of memory

60752/39921 BGP path/bestpath attribute entries using 6075200 bytes of memory

55459 BGP AS-PATH entries using 1446116 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 50333271 total bytes of memory

1 received paths for inbound soft reconfiguration

BGP activity 1495465/1265718 prefixes, 13783077/13432024 paths, scan interval 60 secs

BGP is using around 50MB of memory

but when I issue show processes memory then proccesses are holding for BGP 135MB

PID TTY Allocated Freed Holding Getbufs Retbufs Process

318 0 1659897080 1427661016 135629840 0 0 BGP Router

319 0 0 0 7048 0 0 IP-EIGRP(0): HEL

320 0 1377432 30106984 7064 0 0 BGP I/O

321 0 0 14183240 10064 0 0 BGP Scanner

For what purpose is used more than 80MB (135MB-50MB)?

Is this allocated filed means cumulative alloacation?

If full BGP table uses only 50MB of memory is it

possible have router with only 64MB of RAM?

thanks in advance

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4 (2 ratings)
royalblues Wed, 09/12/2007 - 01:40

I think tHe first command gives you the details of the memory consumed for holding the routes, paths and attributes and not about processes like BGP scanner etc..

Also it is recommended to have 256Mb of RAM to hold a full internet BGP table


guruprasadr Wed, 09/12/2007 - 02:14


It is recommended a minimum of 128 MB of RAM in the router to store a complete global BGP routing table from one BGP peer.

INFO: On the Catalyst 6000 receiving a full BGP table, it is recommended to have MSFC2 with 256 MB of RAM to avoid bug CSCdt13244.

The memory consumption by BGP routes depends on the number of attributes such as multi-path support, soft reconfiguration, number of peers, and AS_PATH.

Refer RFC1774 for more details about BGP Memory requirement.


Best Regards,

Guru Prasad R

Antonio_1_2 Wed, 09/12/2007 - 04:36

So proccess itself uses 80MB of memory, while the bgp table uses only 50MB?

Is that mean that it depends on hardware & software platform, and some other platform may use a less memory for BGP?


This Discussion