IPsec over TCP to VPN3K doesn't work from XP PPPoE client

[mmihalyfi]

• I use the latest Cisco VPN client and VPN 3000 concentrator code

• the MTU is decreased to the default install's 1300

• WinXP with it's built in PPPoE client for ADSL

• UDP works, IPsec over TCP doesn't (from other Internet it works too)

what's wrong? any ideas? thanks!

Martin

[thomas.chen]

Hi Martin,

( Firstly, I assume that you are using TCP because you are inside

some device which uses PAT, else there is not point using TCP )

In the VPN dialer, try checking in the box that says "Enable Trasparent Tunnelling"

If you need to do transparent tunneling using TCP, then on the concentrator under Configuration >

System > Tunneling protocols > IPsec > IPsec over TCP check the box to enble IPsec over TCP and make

sure that the port number to be used is the same on the client and the concentrator.

[mmihalyfi]

Hello Thomas,

Thanks for taking the time to answer.

As I wrote it works well from other type of Internet connection (dial-up), it just doesn't work if it's ADSL with XP's built-in PPPoE connection. Don't know why.

Thanks,

Marton

[mmihalyfi]

Hi Thomas,

I found the root of the problem. It has nothing to do with PPPoE. The built-in firewall was enabled and it drops the VPN client's internal UDP communication to loopback on port 62515.

If I disable it the client can connect fine with TCP.

Now the question is how to add such a rule to allow 127.0.0.1:62515...

Thanks,

Martin