mtu
Use mtu to set the MTU on a tunnel interface.
Use undo mtu to restore the default.
Syntax
mtu size
undo mtu
Default
If the tunnel interface has never been up, the MTU is 64000 bytes.
If the tunnel interface is up, its MTU is identical to the outgoing interface's MTU minus the length of the tunnel headers. The outgoing interface is automatically obtained through routing table lookup based on the tunnel destination address.
Views
Tunnel interface view
Predefined user roles
network-admin
mdc-admin
Parameters
size: Specifies the MTU in the range of 100 to 64000 bytes.
Usage guidelines
After you configure an MTU for a tunnel interface, the configured MTU applies regardless of the tunnel interface status (up/down) and the outgoing interface MTU.
To avoid fragmentation after tunnel encapsulation, set the tunnel interface MTU no greater than the value of the outgoing interface MTU minus the length of the tunnel headers.
Examples
# Set the MTU on Tunnel 1 to 10000 bytes.
<Sysname> system-view [Sysname] interface tunnel 1 [Sysname-Tunnel1] mtu 10000
Related commands
display interface tunnel