What protocols must router permit for VPN on firewall?

[mburnford]

We have a Cisco router connected to the outside interface of a PIX506 firewall running v6. It works fine for SMTP mail and access from inside to Internet, and I now want to set up VPN to it from clients using Cisco VPN Client 3.

The ISP asks what ports and protocols I need opened on the router. I don't know! What ones do I need for clients to run normal Windows operations including a telnet into a UNIX host?

Michael Burnford

[mburnford]

In addition, the Cisco documentation seems to say that the router must support IKE Mode Config, and my ISP says their router (Cisco2500) does not.

Can I still get the VPNClient3 to initiate a connection (presumably using an IP address from the "ip local pool" range)?

If not, how do I do it?