Category: tcp/ip

TCP/IP Tuning

Improving Network Performance When it comes to network performance, unless there is an explicit problem, leave the network optimization to the kernel. If you see a network problem, then study the problem in detail and come up with a solution for that problem, and…

TCP State Diagram

TCP State Diagram TCP goes through different states. The diagram below, which is from Richard Stevens TCP/IP Illustrated Volume 1, should help in understanding the states that TCP goes through.

TCP Header

TCP header is usually 20 bytes unless options are present. Maximum header length is 60 bytes. A typical TCP header contains the following: – Source Port (16 bits) – Destination Port (16 bits) – Sequence bits (32 bits) – Acknowledgement Number (32 bits) **…

IP Header Explained

Mininum 20 bytes, maximum 60 bytes. Maximum size is 65,535 bytes for IP header + data. – Version field (4 bits) for IPv4 or IPv6 – IHL or Internet Header Length (4 bits), it is the number of 32-bit words in the header –…

TCP Flags Explained

TCP Flags TCP has six flags that can help you troubleshoot a connection. The flags are: U – URG A – ACK P – PSH R – RST S – SYN F – FIN When using tcpdump command to troubleshoot network connections, you can…

Understanding IP addresses

In IPv4 there are 5 different IP address classes, Class A,B,C,D,E. Keep in mind that when figuring out number of hosts, we always subtract 2, all 0’s for network and all 1’s for broadcast. Class A – 0 to 127. 2^8 networks, 2^24-2 hosts….

%d bloggers like this:
%d bloggers like this:
%d bloggers like this:
%d bloggers like this:
%d bloggers like this:
%d bloggers like this: