Preventing the LAC From Negotiating L2TP Failover Protocol
The L2TP LAC implementation on MX Series routers supports L2TP failover and peer resynchronization with a failed remote endpoint. The LAC supports both the L2TP failover protocol method and the L2TP silent failover method. By default, L2TP on the LAC attempts to negotiate the L2TP failover protocol with the LNS. When negotiation determines that the LNS supports this method, then the LAC uses L2TP failover protocol if the LNS fails. When the LNS does not support L2TP failover protocol, then the LAC uses silent failover in the event of an LNS failure. The ability to fall back on silent failover prevents the failover from forcing a disconnection of the tunnel to the peer and all the associated sessions.
You can disable the default behavior to force the LAC to operate only in silent failover mode. This configuration can be useful when routers that act as the LNS either are configured for silent failover or incorrectly negotiate use of the failover protocol even though they do not support it. However, when you issue this statement and the LNS supports only failover protocol, then the LAC cannot negotiate failover protocol, and recovery (failover protocol recovery initiated by the LNS) always fails.
To disable negotiation of the L2TP failover protocol:
- Configure disabling.[edit services l2tp]user@host# set disable-failover-protocol
