Chapter 4. Networking Configuration


4.1. TCP Settings

The Transmission Control Protocol (TCP) is a core part of the Internet Protocol (IP) communication protocol suite. Computers use the TCP/IP protocol to communicate with each other when using the Internet.

4.1.1. Adjusting TCP Send/Receive Window Settings

The operating system is a deciding factor in determining the maximum size of the TCP Send and Receive window.

Procedure 4.1. Set the TCP Send and Receive Windows

For Red Hat Enterprise Linux, use the recommended settings to configure the send and receive windows as follows:
  1. Adjust the Send and Receive Window Sizes

    Adjust the size of the send and receive windows by adding the following lines to the /etc/sysctl.conf file as root:
    1. Add the following line to set the send window size to the recommended value (640 KB):
      net.core.wmem_max=655360
      Copy to Clipboard Toggle word wrap
    2. Add the following line to set the receive window size to the recommended value (25 MB):
      net.core.rmem_max=26214400
      Copy to Clipboard Toggle word wrap
  2. Apply Changes Immediately

    Optionally, to load the new values into a running kernel (without a reboot), enter the following command as root:
    # sysctl -p
    Copy to Clipboard Toggle word wrap
    If the user reboots after the first step, the second step is unnecessary.
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat