Option: Configuring an LMP Control Channel
In contrast with statically configured control channels that provide basic connectivity, LMP control channels provide control channel management and link property correlation as defined in RFC 4204, Link Management Protocol (LMP). To manage the state of the control channel, LMP uses the following sequence of events:
- The LMP peer with the highest router ID sends configuration messages to peers.
- When a peer sends an acknowledgement of a Config message back to the originator, the control channel enters the active state.
- When a peer sends LMP hello messages and receives them from a neighbor, the control channel transitions to the up state.
- Once the control channel is up, link summary messages and acknowledgements are sent between LMP peers to share traffic engineering link information.
To configure an LMP control channel, include the lmp-control-channel statement at the [edit protocols link-management peer peer-name] hierarchy level and specify the physical IP address of the peer as the remote address. You can also specify a hello interval, a hello dead interval, a retransmission interval, and a retry limit. Default values for these statements are shown in Table 1.
Table 1: Default Values for LMP Protocol Fields
LMP Protocol Field | Value |
|---|---|
Hello interval | 150 milliseconds |
Hello dead interval | 500 milliseconds |
Retransmission interval | 500 milliseconds |
Retry limit | 3 retries |
If you plan to use these default values, you do not need to configure them. However, if you choose to manually configure any of these values, you must include all four statements (hello-interval, hello-dead-interval, retransmission-interval, and retry-limit) at the [edit protocols link-management peer peer-name lmp-protocol] hierarchy level. Also, the hello dead interval must be at least three times larger than the hello interval.
If you do not want the routing platform to initiate LMP negotiations, include the passive statement at the [edit protocols link-management peer peer-name lmp-protocol] hierarchy level. To log hello packets, other LMP messages, and state transitions of the control channels and traffic engineering links, include the hello-packets, packets, and state traceoptions flags at the [edit protocols link-management traceoptions] hierarchy level.
For a full example of an LMP protocol control channel configuration, see Example: LMP Control Channel Configuration.
 | Note: You can configure either the control-channel statement or the lmp-control-channel statement at the [edit protocols link-management peer peer-name] hierarchy level, but not both statements simultaneously. |
