• Supported Platforms
• M Series
• T Series

• Related Topics
• Neighbor Discovery Overview
• Configuring Protocol Family and Interface Address Properties in the Junos Network Interfaces Configuration Guide

Configuring the MTU Option for Neighbor Discovery Advertisements

In Junos OS Release 10.3 and later, you can configure the link-mtu statement to include the maximum transmission unit (MTU) option in router advertisement messages. The MTU option included in router advertisement messages ensures that all nodes on a link use the same MTU value in situations where the link MTU is not well known.

By default, the MTU option field is not included in router advertisement messages.

To include the MTU option in router advertisement messages, include the link-mtu statement:

To stop including the MTU option in router advertisement messages, include the no-link-mtu statement:

To configure the MTU option for neighbor discovery advertisements:

1. Assign a 128-bit IPv6 address to the interface.
   [edit]user@host# set interfaces ge-2/0/0 unit 0 family inet6 address 2001:DB8::/32
2. Configure the interface to send router advertisement messages that include the MTU option.
   [edit]user@host# set protocols router-advertisement interface ge-2/0/0 link-mtu