Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

L2TP/IPSec with PIX using EAP-TLS


i have big problems with using my PIX515 (SW 7.2.1) for L2TP/IPSec VPN-Connections using EAP-TLS. With the option EAP-Proxy activated on PIX a RADIUS Access-Request Message reaches the configured RADIUS-SERVER (IAS2003), but the request is rejected by Radius. I did inspection of the packets with a sniffer and see following strange behavior:

- There is a Tunnel-Client-Endpoint AVP with no value and, even stranger, an existing AVP titled User-Password with an encrypted value.

I dont understand where the encrypted Password comes from in the first RADIUS Access-Request message received from the PIX, since the authentication method should be certificate-based (EAP-TLS). And I dont know either if the Tunnel-Client-Endpoint MUST be present in the message. Fact is the RADIUS responds with an Access-Reject Message.

The other AVPs in the request seem to be OK, and there is an existend AVP titled EAP-Message (79) that seems alright...

Other detail: In the event log on the IAS the request is logged as Type "PAP" (and not EAP as it should be!) and the log tells me about a problem with wrong username/password.

Tested the same client and Radius configuration using a RRAS-Server from Microsoft instead of the PIX and it worked fine! Could this be a bug of the Pix EAP-Proxy function?

EAP-Proxy should pass all EAP packets unmodified to the Radius, right? This seems not to be the case. Comparing the RADIUS Access-Request Message received from the Pix (which fails) with the RADIUS Access-Request Message received from the RRAS-Server (which successes) shows significant differences.

Every help appreciated. Please ask me for further infos if needed or if you would like me to post the Packet Capture file (Ethereal format)/Configuration information.

Thank you very much!!

Best regards,



Re: L2TP/IPSec with PIX using EAP-TLS

The Cisco Secure PIX Firewall Software Release 6.0 supports VPN connections from the Cisco VPN Client 3.5 for Windows.Refer the following URL for more information

CreatePlease login to create content