The VLAN MTU must be equal to or smaller than the VLAN's "Real Interface" MTU.

  • 7018842
  • 27-Apr-2017
  • 27-Apr-2017


Novell Open Enterprise Server 11 (OES 11) Linux


Need to set the MTU on a VLAN interface to a larger value than it currently is.

For example, at the terminal you could type this command to set the MTU on the vlan0 interface:
ifconfig vlan0 mtu 9000 

If it fails a possible error cold be:
Numerical result out of range


The VLAN interface will have a "real interface" associated with it.
That "real interface" will have a default MTU of 1500 unless otherwise configured.
Set the MTU on the "real interface" to a larger value first, then the VLAN interface can be set up to that same value.


The MTU on the VLAN can never be larger than the MTU on the "real interface"

Additional Information

The VLAN's "real interface" can be a bond interface.

In the /etc/sysconfig/network directory you will find the ifcfg-* files.
Each file contains the MTU setting for that interface.
MTU='9000' would set the interface to 9000 the next time the config file was read. (bootup for example)