45
RIPv2 message format
The format of a RIPv2 message, as shown in Figure 8, is similar to RIPv1.
Figure 8
RIPv2 message format
The differences between RIPv1 and RIPv2 messages are as follows:
•
Version: Version of RIP. For RIPv2, the value is 0x02.
•
Route tag: RIPv2 added Route tags.
•
IP address: In RIPv2, destination IP address 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.
•
Next hop: RIPv2 messages include next hop information. If set to 0.0.0.0, it indicates that
the originator of the route is the best next hop; otherwise, it indicates a next hop better than
the originator of the route.
RIPv2 authentication
RIPv2 sets the AFI field of the first route entry to 0xFFFF to identify authentication information, as
shown in Figure 9.
Figure 9
RIPv2 authentication message
•
Authentication type: A value of 2 represents plain text authentication, while a value of 3
represents MD5.
•
Authentication: Authentication data, including password information when plain text
authentication is adopted or including key ID, MD5 authentication data length, and
sequence number when MD5 authentication is adopted.
