H3C Technologies H3C S7500E Series Switches - Manual (Page 39)

3-4
z Version: Version of RIP, 0x01 for RIPv1.
z Must be zero: This field must be zero.
z AFI: Address Family Identifier, 2 for IP, and 0 for request messages.
z IP Address: Destination IP address of the route. It can be a natural network, subnet or a host
address.
z Metric: Cost of the route, 16 for request messages.
RIPv2 message format
The format of RIPv2 message is similar to RIPv1. Figure 3-2 shows it.
Figure 3-2 RIPv2 Message Format
Command
AFI
IP address
Version Unused
Subnet mask
Next hop
Route tag
Metric
0 7 15 31
Route
Entries
Header
The differences from RIPv1 are stated as following.
z Version: Version of RIP. For RIPv2 the value is 0x02.
z Route Tag: Route Tag.
z IP Address: Destination IP address. It can be a natural network address, subnet address or host
address.
z Subnet Mask: Mask of the destination address.
z Next Hop: 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 message format
RIPv2 sets the AFI field of the first route entry to 0xFFFF to identify authentication information. See
Figure 3-3 .
Figure 3-3 RIPv2 Authentication Message
z Authentication Type: A value of 2 represents plain text authentication, while a value of 3
represents MD5.