ip ospf mtu-ignore

To disable Open Shortest Path First (OSPF) maximum transmission unit (MTU) mismatch detection on received Database Descriptor (DBD) packets, use the ip ospf mtu-ignore command. To return to the default, use the no form of this command.

ip ospf mtu-ignore

no ip ospf mtu-ignore

Syntax Description

This command has no arguments or keywords.

Command Default

OSPF MTU mismatch detection is enabled.

Command Modes

Interface configuration mode

Command History

This command was introduced.

Usage Guidelines

Use the ip ospf mtu-ignore command to disable MTU mismatch detection on an interface. By default, OSPF checks whether neighbors are using the same MTU on a common interface. If the receiving MTU is higher than the IP MTU configured on the incoming interface, OSPF does not establish adjacencies. Use the ip ospf mtu-ignore command to disable this check and allow adjacencies when the MTU value differs between OSPF neighbors.

This command requires the LAN Base Services license.


This example shows how to disable MTU mismatch detection on received DBD packets:

switch(config)# interface ethernet 1/2
switch(config-if)# no switchport
switch(config-if)# ip ospf mtu-ignore

Related Commands

show ip ospf
Displays general information about OSPF routing instances.
show ip ospf interface
Displays OSPF-related interface information.