3Com 10014299 manual Configure the Interval For Sending Hello Messages

612CHAPTER 43: CONFIGURING L2TP

■LAC and LNS authenticate each other.

It can be found that either LAC or LNS can originate tunnel authentication request. However, if one side enables the tunnel authentication, the tunnel can be established only when the passwords on both ends of the tunnel are exactly the same. If tunnel authentication is disabled on both ends, whether or not the tunnel authentication passwords are the same will make no sense.

Perform the following configurations in L2TP group view.

Configure the Interval

for Sending Hello

Messages

Table 676 Set Tunnel Authentication and Password

Operation	Command
Enable tunnel authentication	tunnel authentication
Disable tunnel authentication.	undo tunnel authentication
Set the password of tunnel	tunnel password { simple cipher }
authentication.	password
Remove the password of tunnel	undo tunnel password
authentication.

Tunnel authentication is enabled by default. If no tunnel authentication password is configured, the host name of the router will act as the tunnel authentication password. In order to ensure tunnel security, users are recommended not to disable tunnel authentication.

To ensure the tunnel security, it is recommended that the user should not disable tunnel authentication.

The tunnel authentication password is the router host name, so you must manually configure the tunnel authentication password after the authentication is enabled, and ensure that the password at the LAC side is the same as that at the LNS side.

This configuration is available to LAC and LNS.

To detect the connectivity of the tunnel between LAC and LNS, both the LAC and the LNS will regularly send Hello messages to the peer and the receiving end will make responses upon receiving. If the LAC or LNS does not receive the Hello response within the specified interval, the Hello messages will be repeatedly sent. It no response message from the peer is received after three Hello messages are sent, the local end will assume the L2TP tunnel has already been disconnected. In order to restore connectivity between the LAC and LNS, a new tunnel will have to be established.

Perform the following configurations in L2TP group view.

Table 677 Set the Interval for Sending Hello Message

Operation	Command
Set the interval for sending tunnel hello	tunnel timer hello hello-interval
packet
Restore the interval for sending tunnel	undo tunnel timer hello
hello packet