(Optional) Setting the Hold-max-cost Timer Value
Context
If an LDP session or LDP adjacency over the active link fails but an IGP route for the active link is reachable, a node that has LDP-IGP synchronization enabled uses a Hold-max-cost timer to enable an IGP to advertise LSAs or LSPs carrying the maximum route cost, which delays IGP route convergence until an LDP session or LDP adjacency is established. Therefore, an IGP route for a standby link and an LDP session over the standby link can become available simultaneously.
Setting the Hold-max-cost timer value in the interface view
You can set the Hold-max-cost timer value on a specified interface. This mode applies to the scenario where a few interfaces need to use the Hold-max-cost timer.
Setting the Hold-max-cost timer value in the IGP process
After you set the Hold-max-cost timer value in the IGP process, the Hold-max-cost timers on all interfaces in the IGP process are set to this value. This mode applies to the scenario where many interfaces on a node need to use the Hold-max-cost timer.
- If an IGP carries only LDP services, configure the parameter infinite to ensure that a selected IGP route is kept consistent with the LDP LSP.
- If an IGP carries multiple types of services including LDP services, set the value of the parameter value to ensure that a teardown of LDP sessions or LDP adjacency does not affect IGP route selection or other services.
Procedure
- If OSPF is used as an IGP, perform the following steps:
Set the Hold-max-cost timer on a specified OSPF interface.
- 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.
Set the Hold-max-cost timer on all OSPF interfaces in a specified OSPF process.
- On an Ethernet interface, run undo portswitch
- If IS-IS is used as an IGP, perform the following steps:
Set the Hold-max-cost timer on a specified IS-IS interface.
- 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.
Set the Hold-max-cost timer on all IS-IS interfaces in a specified IS-IS process.
- On an Ethernet interface, run undo portswitch
