[c-nsp] ASR1002-X & (2) full BGP feeds

[Adam Greene]

Hi guys,

 

We have a customer with an ASR1002-X supporting redundant links to the
Internet, currently taking only default routes to both in a primary/failover
scenario. However, they want to have the absolute best path to all
destinations to the Internet, and so are considering taking full routes from
both providers. 

 

According to their research the ASR1002-X supports up to 1,000,000 routes
and to support two full BGP feeds, Cisco recommends upgrading from the
default 1 GB RAM to 16 GB RAM.

 

Questions:

-          It looks like a full BGP routing table is currently about 566,000
routes. Since only the best route to any given destination is stored in the
routing table, is it safe to assume that even taking (2) full feeds, the
customer will stay well below the 1,000,000 route maximum? (the number of
internal routes is negligible)

-          Is 16GB RAM really necessary for (2) full BGP feeds in the real
world? Seems like overkill to me. I seem to recall that when
"soft-reconfiguration inbound" is enabled with (2) peers, it in effect
causes 1.5x or 2x the amount of RAM to be used. However, even with this
caveat, shouldn't 8GB RAM be sufficient?

-          Safe to assume the processor on an ASR1002-X should have no
problem managing 2 full BGP feeds? About 200Mbps aggregate bandwidth
currently flows through the router, and it consistently runs at 0% CPU
utilization

 

Thanks for sharing your experience. 

 

Best regards,

Adam