Routing table size on Cisco ISR 2900, 3900

roger_karam
roger_karam used Ask the Experts™
on
Hello everyone,

Does anyone know where I can find the routing table size for the Cisco 2951 and other ISR generation 2 routers from Cisco?

Thanks,
RAK
Comment
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®

Commented:
routing table size depends on the amount of memory you have in your router:
https://www.cisco.com/en/US/tech/tk365/technologies_q_and_a_item09186a00800949e8.shtml#seventeen
and
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094a83.shtml
with: When running full Internet BGP routes, it is best to have at least 512 MB or 1 GB of RAM on the VIP or line card

Commented:
Hello.

It depends on how much (Free) RAM do you have. If you need full routing table (more than 300k prefixes), you need at least 512MB Ram.  I did several tests few months ago, and for ~80k prefixes you need cca 70MB of memory. Also watch out for CPU utilization!  And yes, we are talking only about IPv4 prefixes :)

Author

Commented:
So there is no predefined limit per memory size?

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial