Configuring Timers

You can configure the following timer values that regulate L2TP tunnel processing:

Hello interval—If the server does not receive any messages within a specified time interval, the router software sends a hello message to the tunnel’s remote peer. By default, the interval length is 60 seconds. If you configure a value of 0, no hello messages are sent. To configure a different value, include the hello-interval statement at the [edit services l2tp tunnel-group group-name] hierarchy level:hello-interval seconds;
Retransmit interval—By default, the retransmit interval length is 30 seconds. To configure a different value, include the retransmit-interval statement at the [edit services l2tp tunnel-group group-name] hierarchy level:retransmit-interval seconds;
Tunnel timeout—If the server cannot send any data through the tunnel within a specified time interval, it assumes that the connection with the remote peer has been lost and deletes the tunnel. By default, the interval length is 120 seconds. To configure a different value, include the tunnel-timeout statement at the [edit services l2tp tunnel-group group-name] hierarchy level:tunnel-timeout seconds;