Routing, IP Routing and its Protocol

IP Routing and its Protocol

What is IP routing/ Routing?

IP routing or routing is the process to move packet from source to destination on other network with the help of routing devices such as router.

There are two ways of routing

• Static Routing
• Dynamic Routing

Static Routing

In static routing all the other networks are configured on router manually. As the number of network increases this task becomes complicated. The command used on router to configure static routing is

ip route <Destination Network Address> <Subnetmask> <Gateway Interface IP/ Number>

Dynamic Routing

In dynamic routing different routing protocols are used to perform routing. In these routing protocols all the network connected to source router are configured in them. They automatically exchange their routing table with the other routers configured with that routing protocol to perform routing.

Most common used routing protocols are

• RIP
• EIGRP
• OSPF
• BGP

RIP

Routing Information Protocol (RIP) is used to perform routing over the network. RIP performs routing over the limited number of hop count which is 15. This means that RIP can exchange its routing table information from First router to 15th router. On 16th router the information of First router routing table can't be shared and that will become unreachable.

There are three versions of RIP

• Version 1 Only supports Class Full IP address of IPv4 which means it can not support Subnetted IP Addresses.
• Version 2 supports both Non-Subnetted and Subnetted IP Address of IPv4.
• Version 3 supports both IPv4 and IPv6 IP Address

EIGRP

Enhanced Interior Gateway Routing Protocol (EIGRP) is advanced routing protocol than RIP. This is also used to perform routing over the network. EIGRP also perform routing over the limited number of hop count by default which is 100 and configurable up to 255. This hop count is much more than RIP.

OSPF

Open Shortest Path First (OSPF) is also a routing protocol which works under the Link State Routing (LSR) Algorithm. The major advantage of OSPF is that it can detect the changes in topology such as Link Failures or Data Load on Link with the help of which it calculates the other shortest path with the help of algorithm named Dijkstra Algorithm.

OSPF is catagrozied in two parts

• Single Area OSPF
• Multi Area OSPF

Single Area OSPF

In Single Area OSPF all the network lies under the same area.

Multi Area OSPF

In Multi Area OSPF there are more than one areas containing some networks in them.

BGP

Border Gateway Protocol (BGP) is a routing protocol which is used to exchange information and data over the internet form one group of network under same Autonomous System (AS) to other group of network having different Autonomous System (AS). We can also say that it is used to connect two or more different ISP's (Internet Service Providers) with each other.

What is Autonomous System (AS)?

Autonomous System (AS) is a unit in router policy which show that network or group of networks controlled by single network admin or group of admins on the behalf of single corporation. AS also represents the routing domain and assigned unique number globally called as Autonomous System Number (ASN).