VPN with PIX 525 and cisco 827 over ADSL connection

[ANGELO DE MASI]

I am trying to implement a VPN connection lan to lan between my central office with a PIX 525 and a branch office with an ADSL connection managed by a cisco router 827 adsl. My ISP provided me just one public IP address which is assigned to atm interface and i use it to allow clients on the network accessing internet through PAT. After I have configured isakmp and IPsec parameters on both Pix and router i was'n able to get VPN on, on debug I can see continually : retrasmission of PHASE 1.

On atm interface i have configured encapsulation AAL5SNAP as reccomended by my ISP but I fear that it's the problem. Isn't It ??

PLEASE can anyone help me? Have anyone been experienced with a such of this scenario? I will greatly appreciate every advice, thanks in advance.

[vijkrish]

What IOS version are you using on the 827 router ? Starting 12.2(4)T3

or 12.2(3) IOS has VPN passthrough feature via PAT.

See Cisco bug id: CSCdu28439. A new document about this feature is being done and pushed to CCO as we speak.

This feature allows you to pass one single ESP Tunnel mode VPN via the 827 router. This should get your VPN going.