HP 6125G HP 6125G & 6125G/XG Blade Switches Layer 3 - IP Routing Confi - Page 29

RIPv1 message format Figure 4 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 5 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. • 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. 19