Routing Information Protocol (RIP)

Routing Information Protocol (RIP) is a dynamic routing protocol used in local and broad-based network. Therefore, this protocol is classified as an interior gateway protocol (IGP). This protocol uses distance-vector routing algorithm.RIP is a distance-vector routing protocol, which employs routing hops as a metric. RIP prevents routing loops by implementing restrictions on the number of hops allowed in a path from source to destination. The maximum number of hops allowed for RIP is 15. This hop limit, however, also limit the size of the network that can support the RIP.A hop 16 is considered an infinite distance and used to denounce inaccessible, inoperable, or routes that are not desirable in the selection process.

Initially each RIP router management updates are transmitted every 30 seconds. At the beginning of deployment, routing table is small enough that traffic is not significant. As networks grow in size, however, it became apparent there might be a massive traffic burst every 30 seconds, even if the router is initialized at random.

There are three versions of the Routing Information Protocol: RIPv1, RIPv2, and RIPng.

RIP version 1

RIP uses the classful routing. Periodic routing updates do not carry subnet information, lacking support for variable length subnet masks (VLSM). This limitation is not possible to have different sized subnets within the same tissue class. In other words, all subnets within the network class must have the same size. There is also no support for router authentication, making RIP vulnerable to various attacks.

RIP version 2

RIP version 2 includes the ability to carry subnet information, thus supporting Classless Inter-Domain Routing (CIDR). To maintain compatibility, the hop limit of 15 fixed. RIPv2 has the facility to fully operate with the original specification should be zero if all the protocol field in RIPv1 messages correctly determined. In addition, the necessary activation of compatibility features that enable interoperability.In an effort to avoid unnecessary load on hosts that do not participate in routing, RIPv2 multicasts entire routing table to all adjacent routers at the address 224.0.0.9, as opposed to RIP using unicast broadcast. Unicast addresses are allowed for special applications.RIPv2 is an Internet Standard STD-56.

RIPng

RIPng (RIP next generation) is an extension of RIPv2 to support IPv6, the next generation Internet Protocol. 

The main difference between RIPv2 and RIPng is:

Description	RIPv2	RIPng
Network Support	IPv4	IPv6
Authentication	Support	Not Support
Needs in the entry route	Encode-hope for every entry route	Encode-specific hope for a set entry route