Maximum IPSec/GRE tunnels

netadmindetail · ‎12-06-2007

Hi All

I found some VPN Performances table for Cisco routers saying that: for exemple 870 series router can support about 10 standard IPSec tunnel. A 1841 with Onboard VPN can support about 100 standard IPSec tunnel. A 3825 with AIM-VPN/SSL-3 can support about 2000 standard IPSec tunnel.

But what about IPSec/GRE tunnel ?

Must I divide those values by 2 ?

I found nothing about that. Can someone help me with this.

Thank you very much !

roluce · ‎12-06-2007

I can say that we haven't seen an issue with GRE being a limiter for GRE/IPSec. An 831 can only do 10 IPSec connections concurrently, and you can run 20 GRE tunnels at the same time from that 831.

In other words, I don't believe there is a direct connection. GRE is a software process, so you would have an issue with CPU or memory, but I don't believe that there is a set limit, or any limit in combination. (none that we've seen)

Rob Luce

netadmindetail · ‎12-11-2007

How many 831 do you have as spokes ?

Are you running DMVPN network ?

Martin