04-04-2017 07:38 AM - edited 03-05-2019 08:18 AM
Hi all
please check my device screenshot
i used to store more then 120,000 routes on my C3825 router
but from the log output , my device was out of memory to store BGP route , and the total numbers of BGP routes was only more 52,000.
any one know what is going on ?
04-04-2017 09:48 AM
Hi
It is a lot routes, are you connected this router to Internet using BGP? It could be being used as a transit router and that is a problem.
If it is a transit router you could block this traffic and avoid be a transit router using ASpath acl + Regular expressions.
04-05-2017 02:23 AM
no i did not connect it as a transit router .
04-05-2017 04:19 AM
Hello,
do you actually need all those 52000 routes ? You obviously could consider route filtering, or working with just default routes.
Either way, check your config for stuff like 'soft reconfiguration inbound/outbound' which as far as I remember doubles the size of the routing table, but is not needed anymore in the latest BGP release.
04-06-2017 03:08 AM
yes , i need them all , actually , there will be more .
04-07-2017 04:14 AM
Hello,
the total memory usage for BGP depends on more factors than only the amount of routes. Can you post the full configuration of your router ?
04-07-2017 09:35 PM
ok
the memory of my c3825 , it show the totoal 's 78MB , do you know what it going on ?
04-08-2017 12:07 AM
Hello,
can you post the output of:
show platform
That output should give you the exact amount of memory...
04-04-2017 12:20 PM
Hello,
52000 routes shouldn't be a problem, if you consider that for the full BGP table (>500K routes) you need about 1 Gigabit of memory.
That said, can you post the configuration of the router, as well as the output of 'show version' ?
04-04-2017 07:02 PM
04-05-2017 06:27 AM
Hello
sh ip bgp neighbors | in Prefix
sh ip bgp sum
Following on from Julo mentioned you can become a transit AS if you peer with two different ISP's and unwittingly adverted their routes to each other, to negate that.a simple regex command would be required.
Regards soft-reconfiguration, Georg is correct this is very resource intensive and nowadays int required - Please review this
Below are the commends to prohibit becoming a transit AS and having soft-reconfiguration inbound disabled>
Example:
ip as-path access-list 10 permit ^$ ( local routes only)
router bgp xx
neighbor <isp1> filter-list 10 out
no neighbor <isp1> soft-reconfiguration inbound
neighbor <isp2> filter-list 10 out
no neighbor <isp2> soft-reconfiguration inbound
res
Paul
04-06-2017 03:03 AM
i did not enable soft-configuration .
do you think any incorrect any on the memory info ?
04-08-2017 05:17 AM
I had always understood that a Full BGP table in modern times (2017) was more around the lines of 8 GB of memory. I have found this to be true with the ISR4k.
04-07-2017 02:58 AM
any reply ?
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide