L2TP Tunnel Pool Configuration

The configuration of the Layer 2 Tunnel Protocol (L2TPv2) pool is optional for subscriber management. It is necessary only if you want to enable L2TP tunneling.

The L2TP pool configuration helps to efficiently organize and manage multiple LNS servers. It allows you to define these sets locally to ensure that L2TP tunnels are directed to the appropriate servers.

Syntax:

set access l2tp-pool <pool-name> <client-name> <server-name> client-ipv4 <client-ipv4>
set access l2tp-pool <pool-name> <client-name> <server-name> preference [0 - 65535]
set access l2tp-pool <pool-name> <client-name> <server-name> secret-encrypted-text <secret-encrypted-text>
set access l2tp-pool <pool-name> <client-name> <server-name> secret-plain-text <secret-plain-text>
set access l2tp-pool <pool-name> <client-name> <server-name> server-ipv4 <server-ipv4>
set access l2tp-pool <pool-name> <client-name> <server-name> session-limit [1 - 65535]

Configuring the L2TP Tunnel Pool

The following command and options allow you to configure an L2TP tunnel pool.

Attribute Description

<pool-name>

Specifies the name of the L2TP pool, which groups L2TP client-server mappings for tunnel establishment.

<client-name>

Specifies the local L2TP tunnel client (LAC) hostname, representing the client initiating L2TP tunnels.

<server-name>

Specifies the remote L2TP tunnel server (LNS) hostname, which terminates L2TP tunnels and provides subscriber services.

client-ipv4

Specifies the IPv4 address of the local L2TP tunnel client (LAC) IPv4 address used for establishing the tunnel.

server-ipv4

Specifies the remote L2TP tunnel server (LNS) IPv4 address to which tunnels are established.

preference

Defines the priority of the LNS within the pool. Lower values indicate higher preference when selecting a server. Default: 0, Range: 1 - 65535.

session-limit

Tunnels with a session limit reached are not considered for further sessions. This limit has precedence over the default session limit specified in the l2tp-profile. Default: 64000, Range: 1 - 65535.

secret-encrypted-text

Configures the shared secret in encrypted form for secure authentication between the LAC and LNS.

secret-plain-text

Configures the shared secret in plain text format. L2TP tunnel secret can be provided as plaintext or an already encrypted text.

The following example shows a local pool with two LNS severs.

This configuration sets an L2TP pool named 'lns-pool-example' with two LNS servers (LNS1 and LNS2). It defines how the device will manage L2TP tunnels. In this example, there are two different LNS server entries for two different LNS servers, LNS1 and LNS2. Both entries belong to the same pool named 'lns-pool-example'. Each entry in the l2tp-pool array defines the configuration for an individual LNS server.

The client-name is specified as BNG, which indicates that the client will initiate L2TP tunnels to the listed LNS servers. The server-name specifies the name of the LNS. Each entry has a unique server name, LNS1 for the first entry and LNS2 for the second.

The client-ipv4 specifies the IPv4 address of the L2TP client, that is BNG. In both entries, the LAC’s IP address is '198.51.100.200'. The server-ipv4 specifies the IPv4 address of the LNS. The first entry has '198.51.100.219' for LNS1, and the second entry has '198.51.100.220' for LNS2.

The secret-encrypted-text parameter specifies the shared secret used for authenticating the L2TP tunnel between the LAC and LNS. The value is encrypted, and the secret is the same in both entries: '$21e4946e31b406de98b3077aef03ed5a7'.

The preference parameter sets the preference value for the LNS server. A lower value generally indicates a higher preference, but in this case, both entries have the same preference value of 1000. The session-limit parameter specifies the maximum number of sessions (L2TP tunnels) that can be established with the LNS server. Both entries have a session limit of 1000.

supervisor@switch: cfg> show config access
{
  "rtbrick-config:access": {
    "l2tp-pool": [
      {
        "pool-name": "lns-pool-example",
        "client-name": "BNG",
        "server-name": "LNS1",
        "client-ipv4": "198.51.100.200",
        "server-ipv4": "198.51.100.219",
        "secret-encrypted-text": "$21e4946e31b406de98b3077aef03ed5a7",
        "preference": 1000,
        "session-limit": 1000
      },
      {
        "pool-name": "lns-pool-example",
        "client-name": "BNG",
        "server-name": "LNS2",
        "client-ipv4": "198.51.100.200",
        "server-ipv4": "198.51.100.220",
        "secret-encrypted-text": "$21e4946e31b406de98b3077aef03ed5a7",
        "preference": 1000,
        "session-limit": 1000
      }
    ]
  }
}

api  To access the RESTCONF API that corresponds to this CLI, click here.