Thursday, December 20, 2012

Static Routing Vs Dynamic Routing

Before trying out the practicals in this post, please make sure that you have a good knowlege in making a simple network in Cisco Packet tracer with IP configuration. If not, you better follow the previous posts and come back to continue.

Also note that you need to have system that we designed in the previous post (How to assign passwords for routers?)loaded in packet tracer to understand the concepts of this posts easily.















Above diagram shows the network that we configured in the previous post.

before starting with static routing and dynamic routing, I prefer if we check the connectivity of the system as it is to make sure that data packets are transferable within any source and destination in the network.

If the configurations are done properly, then data packets could be transferred within same networks. You can check them as below.

Click on PC àcommand promptàtype ping <destination ip address>

By changing the destination IP addresses( as R0’s Fast Ethernet port address, R0’s Serial port address, R1’s Fast Ethernet port, R1’s Serial port and the PC1’s IP address ) you can check the connectivity of the current network.

e.g.:-
 checking connectivity between PC0 and R0’s FE port.


















checking connectivity between PC0 and R0’s Serial port.











checking connectivity between PC0 and R1’s Serial port.














checking connectivity between PC0 and PC1.
















If PC0 cannot send data packets after passing R0’s Serial port, that shows that the hosts in the LAN
can only identify destinations within it but cannot recognize remote network hosts. The same results
would come when check the connectivity between PC1 and other ports separately. Therefore setting
paths in routing should be done by the administrator of the network.

There are two main methods of setting paths of routers.

1. Static routing.
2. Dynamic routing.

Identifying the Static and Dynamic routing methods.

In static routing, the administrator adds roots manually to routers. High security and avoiding overhead in routers are advantages of static routing. But to apply static routing, the admin should have a good knowledge in routing and this could be applied to small networks.

In dynamic routing, the admin doesn't set the paths manually but Routing protocols are followed to identify remote networks and set the paths.

Assigning Static Routing to both the routers and apply necessary configurations

What we are going to do here is, letting each router know about their other destinations. Just like people in our country knowing the country code of some other country to communicate with them. 

First we'll focus on the IT router (R0) to let know about the FINACE (R1) side. It aplies similar to the FINANCE router as well. Just examine the following commands and I'm sure that you'll understand what we are doing.
















Don't get confused about the Next Hop address. It's just the IP address of the serial port of the neighboring router that each router is connected to. for an instance for IT router's serial 0/0/0, the next hop address is the serial0/0/0 port IP address of FINANCE which is 5.0.0.4.

Now   Check the connectivity again.

  • Checking the connectivity between PC0 and all other destinations.
PC>ping 192.168.1.3

Pinging 192.168.1.3 with 32 bytes of data:

Reply from 192.168.1.3: bytes=32 time=94ms TTL=126
Reply from 192.168.1.3: bytes=32 time=78ms TTL=126
Reply from 192.168.1.3: bytes=32 time=94ms TTL=126
Reply from 192.168.1.3: bytes=32 time=78ms TTL=126

Ping statistics for 192.168.1.3:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 78ms, Maximum = 94ms, Average = 86ms

PC>ping 192.168.1.4

Pinging 192.168.1.4 with 32 bytes of data:

Reply from 192.168.1.4: bytes=32 time=63ms TTL=254
Reply from 192.168.1.4: bytes=32 time=63ms TTL=254
Reply from 192.168.1.4: bytes=32 time=62ms TTL=254
Reply from 192.168.1.4: bytes=32 time=47ms TTL=254

Ping statistics for 192.168.1.4:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 47ms, Maximum = 63ms, Average = 58ms

PC>ping 5.0.0.4

Pinging 5.0.0.4 with 32 bytes of data:

Reply from 5.0.0.4: bytes=32 time=63ms TTL=254
Reply from 5.0.0.4: bytes=32 time=63ms TTL=254
Reply from 5.0.0.4: bytes=32 time=63ms TTL=254
Reply from 5.0.0.4: bytes=32 time=63ms TTL=254

Ping statistics for 5.0.0.4:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 63ms, Maximum = 63ms, Average = 63ms

PC>ping 5.0.0.3

Pinging 5.0.0.3 with 32 bytes of data:

Reply from 5.0.0.3: bytes=32 time=31ms TTL=255
Reply from 5.0.0.3: bytes=32 time=31ms TTL=255
Reply from 5.0.0.3: bytes=32 time=31ms TTL=255
Reply from 5.0.0.3: bytes=32 time=31ms TTL=255

Ping statistics for 5.0.0.3:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 31ms, Maximum = 31ms, Average = 31ms


Now the Hosts in both the LANs can identify each other since the routing was done statically.

Do not forget to copy the running-config files to the startup configuration files as shown below. This makes the running-configuration information (that are volatile and lost when the router is switched off). To non-volatile memory in NVRAM.

 Router#copy running-config startup-config