Hi, 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. Thanks, Jane
"Jane" == Pawlukiewicz Jane <pawlukiewicz_jane@bah.com> writes:
Jane> Hi, Good morning. Jane> Quick Question, how much memory does the bgp tables actually Jane> take. I'm estimating 32 mb in my plan, but I'm worried Jane> that's not enough. I guess that depends which BGP implementation you're using... And the number of sessions with full routes... route-views.oregon-ix.net seems to be using about 215Mb, but it has a lot of peers. -- William Waites <ww@styx.org> finger ww@styx.org for PGP keys Idiosyntactix Research Laboratories http://www.irl.styx.org
"Jane" == Pawlukiewicz Jane <pawlukiewicz_jane@bah.com> writes:
Jane> Quick Question, how much memory does the bgp tables actually Jane> take. I'm estimating 32 mb in my plan, but I'm worried Jane> that's not enough. that was 320Mb, no? ;) -- William Waites <ww@styx.org> finger ww@styx.org for PGP keys Idiosyntactix Research Laboratories http://www.irl.styx.org
On Mon, 2002-09-09 at 09:12, William Waites wrote:
"Jane" == Pawlukiewicz Jane <pawlukiewicz_jane@bah.com> writes:
Jane> Quick Question, how much memory does the bgp tables actually Jane> take. I'm estimating 32 mb in my plan, but I'm worried Jane> that's not enough.
that was 320Mb, no? ;)
Here is a show ip bgp summ from a router with 2 full views and 6 iBGP peers, and a couple of customer peers with < 10 routes each: BGP router identifier 209.196.121.1, local AS number 4278 BGP table version is 7175400, main routing table version 7175400 112794 network entries and 505980 paths using 33655314 bytes of memory 89941 BGP path attribute entries using 5037424 bytes of memory 44221 BGP AS-PATH entries using 1134058 bytes of memory 63070 BGP route-map cache entries using 1261400 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory Dampening enabled. 127 history paths, 118 dampened paths 223243 received paths for inbound soft reconfiguration BGP activity 219567/1719967 prefixes, 5720413/5214433 paths, scan interval 60 secs
-- William Waites <ww@styx.org> finger ww@styx.org for PGP keys Idiosyntactix Research Laboratories http://www.irl.styx.org
-- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 972-414-9812 E-Mail: ler@lerctr.org US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749
also fyi #sh ver IOS (tm) RSP Software (RSP-JK8SV-M), Version 12.2(8)T4, RELEASE SOFTWARE (fc1) #sh ip bgp sum 113668 network entries and 263570 paths using 21568596 bytes of memory 83881 BGP path attribute entries using 5034840 bytes of memory 24724 BGP AS-PATH entries using 637716 bytes of memory 16 BGP community entries using 384 bytes of memory 77639 BGP route-map cache entries using 1242224 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory Dampening enabled. 211 history paths, 234 dampened paths BGP activity 286636/18319023 prefixes, 13135930/12871489 paths, scan interval 60 secs #sh mem sum Head Total(b) Used(b) Free(b) Lowest(b) Largest(b) Processor 62AADE40 223683008 126211276 97471732 87582336 93694864 Fast 62A8DE40 131080 82776 48304 48304 48252 -- Stephen J. Wilcox IP Services Manager, Opal Telecom http://www.opaltelecom.co.uk/ Tel: 0161 222 2000 Fax: 0161 222 2008 On 9 Sep 2002, Larry Rosenman wrote:
On Mon, 2002-09-09 at 09:12, William Waites wrote:
"Jane" == Pawlukiewicz Jane <pawlukiewicz_jane@bah.com> writes:
Jane> Quick Question, how much memory does the bgp tables actually Jane> take. I'm estimating 32 mb in my plan, but I'm worried Jane> that's not enough.
that was 320Mb, no? ;)
Here is a show ip bgp summ from a router with 2 full views and 6 iBGP peers, and a couple of customer peers with < 10 routes each:
BGP router identifier 209.196.121.1, local AS number 4278 BGP table version is 7175400, main routing table version 7175400 112794 network entries and 505980 paths using 33655314 bytes of memory 89941 BGP path attribute entries using 5037424 bytes of memory 44221 BGP AS-PATH entries using 1134058 bytes of memory 63070 BGP route-map cache entries using 1261400 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory Dampening enabled. 127 history paths, 118 dampened paths 223243 received paths for inbound soft reconfiguration BGP activity 219567/1719967 prefixes, 5720413/5214433 paths, scan interval 60 secs
-- William Waites <ww@styx.org> finger ww@styx.org for PGP keys Idiosyntactix Research Laboratories http://www.irl.styx.org
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.
Probably not. I assume you're talking about Cisco? I've done some calculations under different circumstances, but the results vary. I think the IOS version and CPU architecture have something to do with that. And then there's stuff like average AS path length and how many other attributes, such as communities, routes tend to have. Quick rule of thumb: about 300 bytes per BGP route, where each route from each peer counts seperately. Don't forget you also need a routing table, which uses about the same (maybe slightly less) per entry, but there is only one entry in the routing table per destination prefix (unless you do load balancing). Finally, you're probably running CEF so that's another several hundred bytes per destination (this one seems to vary the most). A quick guestimate would be: (# full BGP views + 2) * global routing table size * 300 bytes I tried to figure out the numbers for Zebra just the other day, and they were surprisingly similar.
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. - Forrest W. Christian (forrestc@imach.com) AC7DE ---------------------------------------------------------------------- The Innovation Machine Ltd. P.O. Box 5749 http://www.imach.com/ Helena, MT 59604 Home of PacketFlux Technologies and BackupDNS.com (406)-442-6648 ---------------------------------------------------------------------- Protect your personal freedoms - visit http://www.lp.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. -- ========== bep
participants (7)
-
Bruce Pinsky -
Forrest W. Christian -
Iljitsch van Beijnum -
Larry Rosenman -
Pawlukiewicz Jane -
Stephen J. Wilcox -
William Waites