vpn with L2TP update

[Steve]

Hi, after posting the first post, I discovered that if I disable packet
filterig of my ISA server, the client can connect correctly. So I think that
the problem can be that I have to open same outher ports. But wich port??

Thank you
Steve

 

[Bill Grant]

If you are using the NAT-T client, you need to open udp port 4500 in
addition to the normal L2TP/IPSec ports. See MS KB 818043.

 

[Steve]

I have already open this port, but it don't work.

Help me!!!