RIP-2 Enhanced Features
Two versions are available for RIP: RIP-1 and RIP-2. RIP-2 is an extension to RIP-1.
Comparison Between RIP-1 and RIP-2
RIP version 1 (RIP-1) is a classful (as opposed to classless) routing protocol. It supports the advertisement of protocol packets only in broadcast mode. Figure 3-3 shows the packet format. The RIP-1 protocol packet does not carry any mask, so it can identify only the routes of the natural network segment such as Class A, Class B, and Class C, and does not support route aggregation or discontinuous subnet.
RIP version 2 (RIP-2), is a classless routing protocol. Figure 3-4 shows the packet format.
Compared with RIP-1, RIP-2 has the following advantages:
Supports route tag and can flexibly control routes on the basis of the tag in the routing policy.
Has packets that contain mask information and support route summarization and Classless Inter-Domain Routing (CIDR).
Supports the next hop address and can select the optimal next hop address in the broadcast network.
Supports sending update packets in multicast mode. Only RIP-2 routers can receive protocol packets. This reduces resource consumption.
Provides packets authentication to enhance security.
RIP-2 Route Summarization
When different subnet routes in the same natural network segment are transmitted to other network segments, these routes are summarized into one route of the same segment. This process is called route summarization.
RIP-1 packets do not carry mask information, so RIP-1 can advertise only the routes with natural masks. Because RIP-2 packets carry mask information, RIP-2 supports subnetting. RIP-2 route summarization improves extensibility and efficiency and minimizes the routing table size of a large-sized network.
Route summarization is classified into two types:
RIP process-based classful summarization
Summarized routes are advertised using nature masks. For example, route 10.1.1.0/24 (metric=2) and route 10.1.2.0/24 (metric=3) are summarized as a route 10.0.0.0/8 (metric=2) in the natural network segment. RIP-2 supports classful summarization to obtain the optimal metric.
Interface-based summarization
A user can specify a summarized address. For example, a route 10.1.0.0/16 (metric=2) can be configured on the interface as a summarized route of route 10.1.1.0/24 (metric=2) and route 10.1.2.0/24 (metric=3).