Cisco ASR 1002-X and PPTP

Problem: PPTP from any client to an ASR1002-X Cisco does not work. PPTP Connections starts but in PPP LCP phase the connection fails.

Solution: Cisco ASR1002-X with Software IOS-XE 15.3(2)S2 has no PPTP support. You have to take a different Router!

Discussion: The weird thing is, that most of the PPTP stack is still configureable and working, but all packets coming from the client inside the PPTP tunnel are dropped!

Some examples:

.) #show vpdn tunnel
%No active L2TP tunnels
%No active PPTP tunnels

.) in vpdn-group you can set protocol any

.) the router is answering PPTP (TCP 1723)

.) the router starts the PPP layer when a connection is coming in

.) the router even sends LCP O CONFREQ packets to the client

But! The Cisco ASR Router drops every LCP I CONFACK coming from the client.

Cisco was always a reliable piece of hardware for me, but this looks like they removed a feature without removing the code and their QA department worked like this: “it compiles, ship it”.

 

Share on Facebook0Tweet about this on TwitterShare on Google+0Email this to someone