Configuring an LNS Group
Before establishing an L2TP tunnel, create an LNS group and set parameters, such as the source interface, tunnel board, number of tunnels that can be established, and the function of re-marking the packet priorities after performing CAR, for the LNS group.
Context
Each LNS group requires a source IP address (interface IP address) to communicate with a LAC. Based on this IP address, an NetEngine 8000 F determines which LNS group is responsible for processing the request from a certain LAC. Besides the source IP address, other parameters, such as the tunnel board and maximum number of configurable tunnels, can also be configured for an LNS to communicate with a LAC.
Procedure
- Run system-view
The system view is displayed.
- Run lns-group group-name
An LNS group is created, and the LNS group view is displayed.
- (Optional) Run description description-information
A description is configured for the LNS group.
- Run bind slot slot_id
A tunnel board is bound to the LNS group.
Multiple tunnel boards can be configured on the NetEngine 8000 F. You can specify multiple tunnel boards for an LNS group. The round robin load balancing is performed among the tunnel boards based on the number of tunnels.
- Run bind source { interface-type interface-num | interface-name }
An interface is bound to the LNS group.
The IP address of the source interface bound to the LNS group cannot be the same as the IP address of the tunnel source interface on the LAC or the source IP address of the RBS tunnel in a dual-device hot backup scenario.
- (Optional) Run either of the following commands:
To configure load balancing based on the number of tunnels on tunnel boards bound to the LNS group, run the tunnel load-balance by-tunnel command.
To configure load balancing based on the number of sessions on tunnel boards bound to the LNS group, run the tunnel load-balance by-session command.
- Run quit
Return to the system view.
- (Optional) Run l2tp tunnel-limit tunnel-number
The maximum number of allowable L2TP tunnels is configured.
To prevent too many L2TP tunnels on an LNS from deteriorating the LNS performance, perform this step to limit the number of L2TP tunnels.
- (Optional) Run l2tp slot slot-id block enable
Tunnel board blocking is enabled.
If the number of L2TP tunnels established on a tunnel board reaches the upper limit, you can enable the tunnel board blocking function. L2TP tunnels then cannot be established on the tunnel board.
- (Optional) Run l2tp lns fast-reply enable slot slot-id
The tunnel board of the LNS is enabled to send packets to the network-side outbound interface board connected to a LAC based on hardware.
- (Optional) Run l2tp-group group-name
An L2TP group is created, and the L2TP group view is displayed.
- (Optional) Run lns schedule after car
The LNS is enabled to re-mark the priorities of service packets entering a tunnel after performing CAR.
The configuration takes effect only for tunnels established after the command is run.
When an LNS is configured to re-mark the priorities of packets entering a tunnel after performing CAR, the LNS does not support last-mile QoS.
- (Optional) Run tunnel retrans-queue number
The maximum number of concurrent L2TP sessions allowed for an L2TP tunnel is configured. Excess session requests are denied.
- Run commit
The configuration is committed.