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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
The differences between RIPv1 and RIPv2 messages are stated as follows:
•
Version
–Version of RIP. For RIPv2 the value is 0x02.
•
Route tag.
•
IP address
—Destination IP address. It can be a natural network address, subnet address, or host
address.
•
Subnet mask
—Mask of the destination address. Unlike RIPv1, RIPv2 can carry subnet information.
