# Modifying L2TP LAC Default Settings for Managing Destinations, Tunnels, and Sessions

Configuring an E Series router for B-RAS enables the router to operate as an LAC with default settings. You can modify the default settings as follows:

- Enable the verification of data integrity via UDP.
- Specify the time period for which the router maintains dynamic destinations, tunnels, or sessions after termination.

  | Note: The previous two operations also apply to an LNS, however there is no default configuration that enables the LNS.

When the router is established as an LAC or LNS and is creating destinations, tunnels, and sessions, you can manage them as follows:

- Prevent the creation of new sessions, tunnels, and destinations.
- Close and reopen all or selected destinations, tunnels, and sessions.
- Configure drain timeout operations, which control the amount of time a disconnected LAC tunnel waits before restarting after receiving a restart request.
- Configure how many times the router retries a transmission if the initial attempt is unsuccessful.

  | Note: All the commands in this section apply to both the LAC and the LNS.

#### Related Documentation

- Generating UDP Checksums in Packets to L2TP Peers
- Specifying a Destruct Timeout for L2TP Tunnels and Sessions
- Preventing Creation of New Destinations, Tunnels, and Sessions
- Shutting Down Destinations, Tunnels, and Sessions
- Specifying the Number of Retransmission Attempts