Configuring LDP Sessions
Context
The MPLS LDP session is classified into local LDP sessions and remote LDP sessions. You can choose one of the following configurations according to your requirements:
Configuring a local LDP session (based on interfaces)
In most cases, you need to configure a local LDP session when deploying MPLS LDP services.
Configuring local LDP sessions (based on routes)
When the MPLS LDP function is configured, the MPLS LDP function must be enabled globally first and then on all the required interfaces. If too many interfaces need to be enabled with the function, the configuration method wastes too much time and energy, and cannot ensure the configuration accuracy.
After the MPLS LDP function is enabled globally, the function is automatically enabled on the IGP-enabled interfaces and the IGP-based LDP sessions are configured. This simplifies configuration and guarantees the configuration accuracy.
Configuring a remote LDP session
In most cases, remote LDP sessions are not established between adjacent LSRs. A remote LDP session is used for configuring a VPLS in Martini mode.
A local LDP session and a remote LDP session can coexist. That is, two LSRs can establish a local LDP session and a remote LDP session simultaneously. In this case, configurations of the local and remote LDP sessions at both ends must be the same.
Procedure
- Configuring a local LDP session (based on interfaces)
Perform the following steps on two directly connected LSRs.
- On an Ethernet interface, run undo portswitch
The interface is switched to Layer 3 mode.
By default, an Ethernet interface works in Layer 2 mode.
The mode switching function takes effect when the interface only has attribute configurations (for example, shutdown and description configurations). Alternatively, if configuration information supported by both Layer 2 and Layer 3 interfaces exists (for example, mode lacp and lacp system-id configurations), no configuration that is not supported after the working mode of the interface is switched can exist. If unsupported configurations exist on the interface, delete the configurations first and then run the undo portswitch command.
If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.
- On an Ethernet interface, run undo portswitch
- Configuring local LDP sessions (based on routes)
Configure automatic LDP deployment based on Intermediate System to Intermediate System (IS-IS).
Configure automatic LDP deployment based on Open Shortest Path First (OSPF).
- Configuring a remote MPLS LDP session
Perform the following steps on the LSRs on both ends of a remote LDP session.
- Run remote-ip ip-address
The IP address of the remote MPLS LDP peer is configured.
By default, the IP address of the remote LDP peer is not configured.
This IP address must be the LSR ID of the remote MPLS LDP peer. If the LSR IDs of the LDP instance and the local node are different, use the LSR ID of the LDP instance.
Modifying or deleting the IP address of a remote peer leads to deletion of the remote LDP session and MPLS service interruption.
After the IP address of the remote peer is configured using the remote-ip ip-address command, the value of ip-address cannot be used as the IP address of the local interface. Otherwise, the remote session will be interrupted, causing MPLS service interruption.
- Run remote-ip ip-address
