In: Computer Science
Consider the TCP connection mechanism.
i. What mechanism is used to set up a TCP
connection?
ii. Why is the mechanism needed?
iii. Outline how the mechanism works with a diagram.
iv.CLASSFULL AND CLASSLESS IP
i) Three way handshaking protocol(SYN,SYN-ACK,ACK) is used to establish a TCP(Transmission Control Protocol) Connection.
ii)This mechanism is used to create connection between the client and the server node even before actual data is transmitted.
iii) This three way handshaking works in the following three phases.
Phase 1; The client sends the SYN (Synchronize )packet to server to check for any open ports for the connection establishment.
Phase 2: The server, if any open ports are available sends a SYN-ACK (Synchronization-Acknowledgement) packet to the client.The client receives the SYN-ACK packet.
Phase 3: The client upon receiving the SYN-ACK packet sends ACK packet to the server stating that it received SYN-ACK packet
Now the TCP Socket Connection is established.
iv) The terms classless and classfull IP refers to both IP addressing as well as IP Routing.
Classfull IP:
1) These classfull IP addresses have three parts: Network, Subnet ,Host which contains a 8,16, 24 bit network field based on Class A,B or C Addressing Rules.
Class A: First Octet as Network ID and last three Octets as Host ID.
Class B: First two as Network ID and last two Octets as Host ID.
Class C: First three as Network ID and last Octet as Host ID.
2) Example: Routing Information protocol
3) Subnet mask remains the same for complete network.
4) Limited network can be used and this is the main disadvantage.
5) Imposes Restrictions on the usage of the default route while forwarding IP packets.
CLASSLESS IP:
1)Classless addressing has only two parts. Subnet and host . Here the network and the subnet parts are combined into single part called the subnet or prefix.
2) Subnet mask is of variable length also known as VLSM(Variable length subnet mask) and is not of default type.
3) No boundary limitations on host and network id.
4) Example is BGP (Border gateway protocol)
5) Imposes no Restrictions on the usage of the default route while forwarding IP packets.