H3C Technologies H3C SecPath F5020 - Manual (Page 46)

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Step Command Remarks
3. Enable L2TP tunnel
authentication.
tunnel authentication Enabled by default.
4. Configure the tunnel
authentication key.
tunnel password { cipher | simple }
password
By default, no key is configured.
Setting the Hello interval
To check the connectivity of a tunnel, the LAC and LNS periodically send each other Hello packets. At
receipt of a Hello packet, the LAC or LNS returns a response packet. If the LAC or LNS receives no
response packets from the peer within a specific period of time (the Hello interval), it retransmits the Hello
packet. If it receives no response packets from the peer after transmitting the Hello packet five times, it
considers the L2TP tunnel to be down.
To set the Hello interval:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter L2TP group view.
l2tp-group group-number [ mode { lac
| lns } ]
N/A
3. Set the Hello interval. tunnel timer hello hello-interval The default setting is 60 seconds.
Enabling session flow control
The L2TP session flow control function adds sequence numbers to transmitted packets, and uses them to
reorder packets arriving out of order and to detect lost packets.
This function takes effect on both sent and received L2TP data messages. The L2TP sessions support this
function if either the LAC or LNS is enabled with this function.
To enable session flow control:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter L2TP group view.
l2tp-group group-number [ mode { lac
| lns } ]
N/A
3. Enable the session flow
control function.
tunnel flow-control
By default, this function is
disabled.
Configuring the DSCP value of L2TP packets
The Differentiated Services Code Point (DSCP) field is the first 6 bits of the IP ToS byte. This field marks the
priority of IP packets for forwarding. This feature sets the DSCP value for the IP packet when L2TP
encapsulates a PPP frame into an IP packet.
To configure the DSCP value of L2TP packets: