Give the name of protocols used by different layers of TCP/IP. Discuss the function of ARP and RARP.
Give the name of protocols used by different layers of TCP/IP. Discuss the function of ARP and RARP.
1 Answer
TCP/IP Model contains following layer.
1) Host-to-Network Layer -
It defines characteristics of transmission media.
It also concern with delivery of data when two systems are attached to same network
SLIP
PPP
2) Internet Layer –
This layer permits host to inject packets into network and packet travels independently to destination.
This layer defines packet format and protocol called IP (internet Protocol)
ARP
RARP
IP
3) Transport Layer -
It has TCP and UDP.
TCP (transmission control protocol) –it is Reliable & connection oriented protocol.
UDP (User Datagram Protocol)- it is Unreliable & connectionless protocol.
4) Application Layer -
It includes virtual Terminal (TELNET), file transfer Protocol (FTP), simple Mail Transfer
Protocol (SMTP) and other protocols like HTTP, WWW, DNS.
ARP:(Address resolution protocol)
Networking H/W demands that a datagram contain the physical address of the intended recipient.
If problem Address Resolution protocol (ARP) was developed.
ARP takes the IP address of a host as input & gives its corresponding physical address as the output.
As if doesn‟t know who must be having address if sends the broadcast message to all the computer on the network.
The computer whose IP address matches the broadcast IP address sends a reply and along with if, its physical address to the broadcasting computer.
All other computers lignose the broadcast message as IP address is different Now, when it is responding whose IP address gets match is aware of the sender.
So it doesn‟t require sending broadcast message.
As it knows sender hardware as well as IP address that the reason it uncast the reply so that senders only receive it.
RARP: (Reverse Address Resolution protocol)
ARP is used for solving the problem of finding out which Ethernet address corresponding to a given IP address.
But sometimes we have to solve a reverse problem. That means we have to obtain the IP address corresponding to the given Ethernet address.
Such a problem can occur when booting a diskless workstation.
The problem of obtaining the IP address when an Ethernet address is given, can be solved by using RARP(Reverse Address Resolution protocol)
The newly booted workstation is allowed to broadcast its Ethernet address. The RARP server looks at this request. Then it looks up the Ethernet address in its configuration files and sends back the corresponding IP address.
Using RARP is actually better than embedding an IP address in the memory image because it allows the same image to be used on all machines.
If the IP address were buried inside the image, each workstation would need its own image.
The disadvantage of RARP is that it uses a destination address of all ls(limited broadcasting) to reach the RARP server.
But such broadcasts are not forwarded by routers, so a RARP server is needed on each network.
1) Host-to-Network Layer -
It defines characteristics of transmission media.
It also concern with delivery of data when two systems are attached to same network
SLIP
PPP
2) Internet Layer –
This layer permits host to inject packets into network and packet travels independently to destination.
This layer defines packet format and protocol called IP (internet Protocol)
ARP
RARP
IP
3) Transport Layer -
It has TCP and UDP.
TCP (transmission control protocol) –it is Reliable & connection oriented protocol.
UDP (User Datagram Protocol)- it is Unreliable & connectionless protocol.
4) Application Layer -
It includes virtual Terminal (TELNET), file transfer Protocol (FTP), simple Mail Transfer
Protocol (SMTP) and other protocols like HTTP, WWW, DNS.
ARP:(Address resolution protocol)
Networking H/W demands that a datagram contain the physical address of the intended recipient.
If problem Address Resolution protocol (ARP) was developed.
ARP takes the IP address of a host as input & gives its corresponding physical address as the output.
As if doesn‟t know who must be having address if sends the broadcast message to all the computer on the network.
The computer whose IP address matches the broadcast IP address sends a reply and along with if, its physical address to the broadcasting computer.
All other computers lignose the broadcast message as IP address is different Now, when it is responding whose IP address gets match is aware of the sender.
So it doesn‟t require sending broadcast message.
As it knows sender hardware as well as IP address that the reason it uncast the reply so that senders only receive it.
RARP: (Reverse Address Resolution protocol)
ARP is used for solving the problem of finding out which Ethernet address corresponding to a given IP address.
But sometimes we have to solve a reverse problem. That means we have to obtain the IP address corresponding to the given Ethernet address.
Such a problem can occur when booting a diskless workstation.
The problem of obtaining the IP address when an Ethernet address is given, can be solved by using RARP(Reverse Address Resolution protocol)
The newly booted workstation is allowed to broadcast its Ethernet address. The RARP server looks at this request. Then it looks up the Ethernet address in its configuration files and sends back the corresponding IP address.
Using RARP is actually better than embedding an IP address in the memory image because it allows the same image to be used on all machines.
If the IP address were buried inside the image, each workstation would need its own image.
The disadvantage of RARP is that it uses a destination address of all ls(limited broadcasting) to reach the RARP server.
But such broadcasts are not forwarded by routers, so a RARP server is needed on each network.