NAT - Tunnelling IPSEC within a GRE tunnel - has anyone done this

[maddog32]

Hi,

I'm using L2TP/IPSEC to create a Win2k VPN solution from a client to an Adv Server. In the middle there are some Cisco routers that are performing NAT which is obviously causing problems.

In order to overcome these problems I wondered whether anyone has tried creating a GRE tunnel between two routers and then encapsulating the IPSEC packets within the GRE tunnel. Provided NAT is performed after the creation of the GRE packet this should work. Shouldn't it?

Is anyone using this approach? Am I talking rubbish? How has everyone else solved this problem (excluding using PPTP!).

Cheers.

 

[Guest_imported]

This will work. I use GRE for nearly all of my router to router traffic. You should set up your acls carefully though to prevent redundant encryption.