Try typing GRE instead of TCP or UDP in your NAT statements. GRE is its own
protocol.
If NAT can't be configured to handle GRE specifically, you should be able to
configure NAT to staticly translate the IP, and then access-list the public
IP to permit only GRE & TCP 1723.
access-list 111 permit gre any host {destination-host-public-ip}
access-list 111 premit tcp any host {destination-host-public-ip} eq 1723
access-list 111 deny ip any host {destination-host-public-ip}
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:13:33 EDT