23
•
Supports plain text authentication and MD5 authentication to enhance security.
NOTE:
RIPv2 has two types of message transmission: broadcast and multicast. Multicast is the default type using
224.0.0.9 as the multicast address. The interface working in the RIPv2 broadcast mode can also receive
RIPv1 messages.
RIP message format
A RIP message consists of a header and up to 25 route entries. (A RIPv2 authentication message uses the
first route entry as the authentication entry, leaving 24 available.)
RIPv1 message format
Figure 6
RIPv1 message format
•
Command—Type of message. 1 indicates request, which is used to request all or part of the routing
information from the neighbor; 2 indicates response, which contains all or part of the routing
information. A response message consists of up to 25 route entries.
•
Version—Version of RIP, 0x01 for RIPv1.
•
Must be zero—This field must be zero
•
AFI—Address Family Identifier, 2 for IP.
•
IP address—Destination IP address of the route that can be a natural network, subnet, or a host
address.
•
Metric—Cost of the route
RIPv2 message format
The format of RIPv2 message is similar to RIPv1.
Figure 7
RIPv2 Message Format
Command
AFI
IP address
Version
Must be zero
Subnet mask
Next hop
Route tag
Metric
0
7
15
31
Route
Entries
Header
