topic IPSec Tunnel PAN to Cisco ASA - matching for phase 2 in General Topics

IPSec Tunnel PAN to Cisco ASA - matching for phase 2

palomed — Tue, 09 May 2017 16:26:28 GMT

Do the proxy ID's on the pan side have to match the ACL defined crypto domain on the ASA? That is - suppose on the PAN side you had for phase II of the tunnel 192.168.1.0, 192.168.2.0 and 192.168.3.0 while the ASA side had only 192.168.1.0 and 192.168.2.0. Would phase II tunnel still come and allow traffic for the first two subnets? Or would both sides need to match precisely in order for phase 2 to successfully come up at all? Thank you.

Re: IPSec Tunnel PAN to Cisco ASA - matching for phase 2

TranceforLife — Tue, 09 May 2017 17:02:27 GMT

I think l had a similar case some time ago. Where customer added an additional subnet on one side but forgot to configure a proxy id. This was bringing a tunnel down. So yes proxy id`s have to match, otherwise, the tunnel will be coming up/down (flapping). I always imagine a proxy id`s as a additional authentication keys then should match on the both sides.

Re: IPSec Tunnel PAN to Cisco ASA - matching for phase 2

Raido_Rattameister — Tue, 09 May 2017 17:09:41 GMT

@TranceforLife If you expect Proxy ID to give additional security then avoid using aggressive mode and stick to main... 🙂

Re: IPSec Tunnel PAN to Cisco ASA - matching for phase 2

palomed — Tue, 09 May 2017 17:59:19 GMT

Well it's not so much that I want extra security. I need to migrate the tunnel to a new data center and in the process we found defunct subnets, overlapping subnets etc etc. So I tried to clean up as best possible. But I was trying to determine if me and the partner are not entirely in-sync if the tunnel would still come up. Tunnel turn-up is always a nightmare. 🙂