Configuring an Interface to Fill in DD Packets with the Actual MTU

Procedure

1. Run system-view

   The system view is displayed.

2. Run interface interface-type interface-number

   The OSPF interface view is displayed.

3. 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.

4. Run ospf mtu-enable

   The interface is configured to fill in DD packets with the actual MTU and check whether the MTU in DD packets received from a neighbor exceeds the MTU of the local end.

   By default, the MTU in DD packets sent by an interface is 0.

   Setting the MTU in a DD packet will lead to the re-establishment of the neighbor relationship.

5. Run commit

   The configuration is committed.