The linktrace protocol is used for path discovery between a pair of maintenance points. Linktrace messages are triggered by an administrator using the traceroute command to verify the path between a pair of MEPs under the same maintenance association. Linktrace messages can also be used to verify the path between an MEP and an MIP under the same maintenance domain. The operation of IEEE 802.1ag linktrace request and response messages is similar to the operation of Layer 3 traceroute commands. For more information about the traceroute command, see the JUNOS System Basics Configuration Guide.