Change the TCP/IP tuning parameters in Linux

All TCP/IP tuning parameters are located under the /proc/sys/net/ directory. For example, here is a list of the most important tuning parameters, along with a short description of their meaning:

1. /proc/sys/net/core/rmem_max - Maximum TCP Receive Window.
2. /proc/sys/net/core/wmem_max - Maximum TCP Send Window.
3. /proc/sys/net/ipv4/tcp_timestamps - Timestamp ( RFC 1323) add 12 bytes to the TCP headers.
4. /proc/sys/net/ipv4/tcp_sack - TCP selective acknowledgments.
5. /proc/sys/net/ipv4/tcp_window_scaling - support for large TCP Windows (RFC 1323). Needs to be set to 1 if the Max TCP Window is over 65535.
6. mem_default = Default Receive Window.
7. rmem_max = Maximum Receive Window.
8. wmem_default = Default Send Window.
9. wmem_max = Maximum Send Window.

Everything under /proc is volatile, so any changes made are lost after a reboot.

Read More