Topology: PC------LAC(R vendor) ------LNS(R2600);
Failure descriptions: PC can dial in normal, but it cannot dial in after a while.
The debug is switched on when the user is dialing, and the fault prompt as L2TP::Error::receive invalid AVP in ICCN is found.
In l2tp-group, add the mandatory authentication of mandatory-lcp and the problem is solved.
Default L2TP group
allow l2tp virtual-template 1
tunnel password simple XXXX
According to debug information, we can find that the tunnel has set up normally, but it fails to negotiate with LAC.
At the beginning, configure mandatory-lcp.