Vyatta NOS documentation

Learn how to install, configure, and operate Vyatta Network Operating System (Vyatta NOS), which helps to drive our virtual networking and physical platforms portfolio.

interfaces dataplane <interface-name> vif <vif-id> mtu <mtu>

Set the maximum transmission unit (MTU) for a vif.

set interfaces dataplane interface-name vif vif-id mtu mtu
delete interfaces dataplane interface-name vif vif-id mtu
show interfaces dataplane interface-name vif vif-id mtu

The default size of the MTU is 1500.

interface-name
The name of a data plane interface. For more information about the supported interface name formats, refer to Data Plane Interface.
vif-id
The ID of a vif. The ID ranges from 1 through 4094.
mtu
The size of the MTU, in octets, for the vif as a whole. The size of the MTU ranges from 68 through 9000.

Configuration mode


interfaces {    
   dataplane interface-name {
        vif vif-id {
            mtu mtu
        }
    }
}

Use this command to set the size of the maximum transmission unit (MTU) for a vif.

During forwarding, IPv4 packets larger than the MTU are fragmented unless the “Don't Fragment” (DF) bit is set in the IP header. In that case, the packets are dropped and an ICMP “fragmentation needed” message is returned to the sender.

Note that MTU sizes larger than 1500 cause the system to generate “jumbo frames,” which are not compatible with some data plane interface cards and devices.

If the data plane interface is part of an Ethernet link bond, MTU settings for the bonded link override MTU settings for the physical interface.

Use the set form of this command to specify the size of the MTU.

Use the delete form of this command to delete the size of the MTU and restore the default size of 1500.

Use the show form of this command to display the current size of the MTU.