24-port NWay Ethernet Switch User’s Guide
124
Switch Management and Operating Concepts
Figure 5-21. Rip Message Format
RIP 2 also attaches a 16-bit
Route Tag
to each entry. A router
must send the same tag it receives when it transmits the route.
Thus, the tag provides a way to propagate additional information
such as the origin of the route. In particular, if RIP2 learns a
route from another autonomous system, it can use the
Route Tag
to propagate the autonomous system’s number.
Because the version number in RIP2 occupies the same octet as
in RIP1, both versions of the protocols can be used on a given
router simultaneously without interference. Before processing
an incoming message, RIP software examines the version number.
