RIP

Routing Information Protocol

Routing Information Protocol generally called as RIP. RIP is a dynamic, non-Cisco proprietary, distance vector routing protocol. RIP calculates the best route based on hop count. RIP is a flexible, simple configuration protocol thus made this protocol a successful protocol. Features Rip protocol’s AD no#120 AD no# Administrative Number Non-Cisco proprietary protocol Metric-hop count Maximum HOP count is 15,thus RIP works only with 15 routers, If 16th router is added then the 16th router will not be able to include in the network using RIP As no# ( Autonomous system number) is not supported It support 4 equal paths for load balancing RIP sends entire routing table to its neighbour router. There are currently two versions of RIP protocol. RIPv1, and RIPv2 RIPv1 Features

1. Rip v-1 is a Class full Routing protocol
2. Does not send subnet mask with routing table
3. Does not support VLSM and summarization
4. Rip v-1 does not support authentication, which leads to security risk and possibility of hacking thus delivering transferred packet to some other hackers destination

RIP v2:

RIP v2 is a revised version derived from RIP v1.

Special features in rip V2:

1. It is a class less protocol
2. It sends subnet mask with routing table
3. It supports VLSM and summarisation
4. It supports authentication
5. It adds router tag thus to differentiate between internal and external router.

Disadvantages:

• Inability to support paths longer than 15 hops
• Reliance on fixed metrics to calculate routes
• Network intensity of table updates
• Relatively slow convergence
• Lack of support for dynamic load balancing

Difference between RIPv1 & RIPv2

RIPv1	RIPv2
Class full	Classless
Broad cast based	Multicast based (224.0.0.9)
VLSM is not supported.	Supports VLSM networks.
No authentication required.	It has MD5 authentication.
Discontinuous networks are not supported.	It supports discontinuous networks

Operation

Rip protocol which uses distant vector protocol periodically exchanges its own routing tables to their immediate network neighbours routers. A router's routing table contains information about the distance between itself, Metric information and known destinations. These destinations can be individual host computers, printers, servers or other networks. Thus all routers will gather details about all other routers details in the same network. And updates the tables periodically.

RIP TIMERS

Router Timer	Description	Time in Seconds
Hello timer (or) Update Timers	It specifies how frequently routing messages will be sent	30 seconds
Invalid Timer	It specifies how long a router should wait in the absence of a routing-update message of a specific route before declaring it invalid	SIX times the Update timer, 180 seconds
Hold-down Timer	It specifies the hold-down period	Same as invalid timer180 seconds
Flush Timer	It indicates how much time should pass before an RIP route is removed from the routing table.	Seven times the routing update period, 240 seconds.

Rip configuration:

Syntax

Router (config) #router RIP

Router (config-route) #network (directly connected network address)

Example:

Let us configure RIP protocol in network made of 3 routers, 3 switches and 9 pc

With ip address and network connections as in figure below

Router#1

London router

London (config) #router RIP

London (config-route) #network 10.0.0.0

London (config-route) #network 192.168.100.0

Router#2

New Delhi router

New Delhi (config) #router RIP

New Delhi (config-route) #network 11.0.0.0

New Delhi (config-route) #network 192.168.100.0

New Delhi (config-route) #network 192.168.101.0

Router#3

Hongkong router

Hongkong (config) #router RIP

Hongkong (config-route) #network 12.0.0.0

Hongkong (config-route) #network 192.168.101.0

RIP summary

RIP Types	RIP V-1,RIP V-2
Metric	HOP count(max. 15# routers)
Load balancing	4 equal path
Administrative Number(AD) no#	120
Autonomous system (AS) no#	NOT APPLICABLE
Syntax Router (config) #router RIP Router (config-route) #network (directly connected network address)