IP Routing

IP Routing

Routing  =   Path determination  + Switching

Routing means to find best way for sending packets or  it means to search best path for communication.  Routing has 2 components :-

(a)Path determination    It means to find best route.

(b)Switching               It mean to actually send packets over the pre-defined path.

There are 3 types of switching :-

(1) Packet switching

(2) Message switching

(3) Circuit switching

Routing process use 2 types of protocols :

1. Routing protocol

2. Routed protocol

1. Routing protocol     It is use to find the best route automatically. It has 2 types :-

(i) IGP (Interior Gateway Protocol)  It is use within Intranet. Eg:  RIP, IGRP, EIGRP, OSPF etc.

(ii)EGP (Exterior Gateway Protocol)  It is use to connect the different environments or different Intranets. Eg: BGP, IS-IS etc.

There are 2 categories for the routing protocol :-

(a) Classless       They refer to Link State routing protocol, they can use subnet mask in their                               routing table updates, they can support subnetting and supernetting. They                               are more intelligent. Eg:  EIGRP,  OSPF etc.

(b) Classful         They refer to Distance Vector routing protocol,  they cannot support                                         subnetting and supernetting.  They cannot use subnet mask in their routing                            table updates , they can send routing updates to the broadcast address                           (255.255.255.255)  Eg:  RIP, IGRP  etc.

Routing protocol use some information to find the best route automatically, these information are known as Routing Metric:-

(a) Hop count     It means routers between source and destination.

(b) Bandwidth     It is data carrying capacity of a network in bits per second.

(c) Congestion    it means network traffic.

(d) Delay           It means time for which packet is hold by router before passing it to the next                     hop. Maximum delay can be 5 minutes.

(e) AD (Administrative Distance)    It means reliability or distance between two routers. If AD                             number is less, then route  is more reliable.  AD for RIP=120, EIGRP=90 and                  OSPF=110, so EIGRP is most reliable in these 3 routing protocols.

(f) MTU (Maximum Transmission Unit)  It is maximum size of packet or message which can be                      pass by router. MTU is an important metric in Message Switching.

2. Routed Protocol     It is use to actually send packet over the pre-defined path, it is carrier protocol. Eg: IP, IPX etc.

Terms use in routing are :-

1. AS (Autonomous System)    It means Intranet with centralize administration or it is a domain with routing environment.

2. Area     It means subnet or branch office.

3. IS (Intermediate System)  Any device which can forward packets or which can perform routing function. Eg: Router, Switch etc.

4. ES (End System)     Any device which cannot forward packet. Eg: PC, Printer etc.

5. Hello   When any computer or router will be connect in network, then it will broadcast its information to other devices.;

6. Heartbeat    It means each router will advertise itself or send signals to other routers after every 30 seconds.

7. Blackhole   It is router which does not respond to heartbeat.

There are 2 types of routing :-

1. Static Routing    It means route will be create by administrator, no routing protocol will be use, it is faster, AD is always 1, it does not have fault tolerance, it can be use in small network and it cannot be use in the complex network.

2. Dynamic Routing   It means route will be define by the routing protocols automatically. It has fault tolerance or redundancy. It can be use in very large networks and complex networks.

NOTE: We can also use Hybrid routing and Default routing.

To configure Windows Server as Router :-

NOTE: Router is a networking device which can connect different network ID.

Open Server Manager    -> Add Roles    -> Network Policy Server (NPS) (and Remote Access in Win2012)    -> Routing and Remote Access      -> Install

Open Administrative tools      -> Routing and Remote Access     -> Configure and Enable Routing and Remote Access    -> Custom Configuration      -> LAN Routing    -> Finish

Assign IP address for different network ID(two IP addresses for two Networks).

Give default gateway in each client machine.