Routing

• Routing– Forwarding of packets from one network to

another network choosing the best path from the routing table.

– Routing table consist of only the best routes for every destinations.

Routing Network Diagram

E0 10.1.1.1/8

HYD

LAN – 10.0.0.0/24

E0 20.1.1.1/24

KSA

LAN – 20.0.0.0/24

1.1.1.1/8S0

S11.1.1.2/8

• Head Office Ethernet interface should be in the same network as your Head office LAN and similarly on Branch Office side.

• Head Office S0 and Branch Office S1 should be in same network.

• Head Office LAN and Branch Office LAN should be in different Network.

• All interfaces of Router should be in different network.

Rules of Routing

• Static Routing

• Default Routing

• Dynamic Routing

Types of Routing

• It is configured by Administrator manually.

• Mandatory need of Destination Network ID

• It is Secure & fast

• Used for Small organizations with a network of 10-15 Routers.

• Administrative distance for Static Route is 0 and 1.

• It is the “trustworthiness” of the routing information. Lesser the Administrative distance, higher the preference.

Disadvantages :-• Used for small network.

• Everything to manually

• Network change effect complete n/W

Static Routing

Configuring Static Route

Router(config)# ip route <Destination Network ID> <Destination Subnet Mask> <Next-hop IP address >

Or

Router(config)# ip route <Destination Network ID> <Destination Subnet Mask> <Exit interface type><interface

number>

Example: ip route 11.0.0.0 255.0.0.0 10.0.0.2

Routing Network Diagram

E0 10.1.1.1/8

HYD

LAN – 10.0.0.0/24

E0 20.1.1.1/24

KSA

LAN – 20.0.0.0/24

1.1.1.1/8S0

S11.1.1.2/8

• A Default routing protocol is configured for unknown destinations.

• Generally used in the internet where the destinations are unknown.

• Example : The address of yahoo is unknown.

• Configured at end points

• It is the last preferred routing

• Default routes help in reducing the size of your routing table.

Default Routes

Default Routing - Real Time Example

E0 192.168.1.150/24

LAN - 192.168.1.0/24

E0 202.54.30.150/24

IP 202.54.30.1/24

HYD

INTERNET

Configuring Default Route

Router(config)# ip route <Destination Network ID> <Destination Subnet Mask> <Next-hop IP address >

OrRouter(config)# ip route <Destination Network ID>

<Destination Subnet Mask> <Exit interface type><interface

number>