Vyatta Network OS Documentation

Learn how to install, configure and operate the Vyatta NOS, which helps drive our virtual networking & physical platforms portfolio.

interfaces dataplane <interface-name> mtu <mtu>

Sets the size of the MTU for a data plane interface.

set interfaces dataplane interface-name mtu mtu
delete interfaces dataplane interface-name mtu
show interfaces dataplane interface-name 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.
mtu
The size of the MTU, in octets, for the interface as a whole, including any logical interfaces configured for it. The size of the MTU ranges from 68 through 9000.

Configuration mode

interfaces {
    dataplane interface-name {
        mtu mtu
    }
}

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

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.