How IP routing works

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The routing acts as the main support for sending the data from one device to the other by using the network. For transferring data the IP network acts as like a bridge between the two different devices. During transfer the data had been broken into smaller units that are called as packets. This data unit would carry along with data, a header which contains the information’s.

  • The information includes:
  • IP addresses
  • The source device
  • The destination device

The routing is similar to the switching concepts and for IP routing the IP address had been used for forwarding IP packets from its source to destinations.

How does it get transferred?

The transfer of data would take place step by step in sequential order if in case any problem occurred in the middle there is a lot of a possibility for the data to get lost.

  • The host X open the command prompt and he enter some IP address (Eg: 100.100.100.001).
  • The IP would immediately start up its work with the “Address resolution protocol” to determine or check out in which network this packet had been destined based on the IP address and subnet host mask.
  • The data would be sends through the router because only then the data could able to get diverted into the correct network. After that the host X can send the packets to the router for that the hardware address of that particular router would get connected.
    • In case if the address is not found then the message would be sends to the ARP broadcast that contains the MAC.
    • Through which it can able to identify it for this process to happen there require a sufficient amount of time. This is the main reason why sometimes the ping gets time out.

This all process would be carried out with the help of router and now the host X is ready to transmit the packets.

How does the IP router start working?

Once everything is ready the network layer would be ready to receive data from the data link layer from there the packet is being generated. That particular packet would contain source and destination IP address along with ICMP requests. You can also check Router Instructions for more information.

The data link layer would create a frame that would encapsulate the particular packet with its information that is need for the packet to transmit on local network.

  • It includes the source and destination hardware address – MAC
  • It also contains the type of the network protocol layer like IPV4 or IPV6
  • At end it would carry out the frame to cyclic redundancy check that is used to find the repetition of data.

After the check had been over it would hand over the rest to the physical layer which would start its encoding from 1s to 0s. That is into the digital signal and transmits this out on the local physical network.

  • The signal had been picked up by the router EO interface and there it starts reading the frame.
  • It checks CRC and compared up with the CRC values of the host.
  • Then the hardware address of the destination would be checked out whether it is correct or not.
    • When it gets matched then from that it would check out its field of the frame would be checked out.
    • Then IP is a main field it would be sends to it and hands the packet to the IP protocol that had been running on the router.
  • Here the frame would be stripped and the original packet would be generated by host X (in router buffer you data would be found there).

Then the IP would looks into the packets destination IP address that used to determine whether the packet is for the router (it would start linking up). It connects up with the network on interface E1.

The router would place the packet in the buffer of interface E1. There the router would create a frame set of packet to the destination host.

  1. Router looks into the ARP for checking whether the hardware address had already been resolved.
  2. If not then it would send that information to the ARP broadcast out of E1 to find its specific address.

Destination process

Now host Y would responds with specific hardware address with its network interface card ARP. Actually the E1 interface would have everything that had too been sends to the final destinations. Only inside that interface it holds the required data.

Then the host Y would receive the frame and it would run a CRC and it would start checking out. After that it would discards its frame and hands to the packets of IP. Then the IP would check out its destination IP address. Finally the host Y would receive the data.

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