---
title: "How to Tune the Linux Kernel for Networking"
slug: "kernel-tuning"
updated: 2025-12-23T15:05:21Z
published: 2025-12-23T15:05:21Z
canonical: "docs.swxtch.io/kernel-tuning"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.swxtch.io/llms.txt
> Use this file to discover all available pages before exploring further.

# How to Tune the Linux Kernel for Networking

**WHAT TO EXPECT**

**In this article**, users will learn how to tweak the Linux kernel for increased packet rates, minimizing packet trops.

**PLEASE NOTE**

Kernel Tuning should be the last option when setting up and configuring the Linux xNIC for performance. We expect users to validate network loss BEFORE attempting to optimize/tune the network kernel.

These settings have been found to increase packet rates and minimize packet drops. These settings are for implementing on a Linux machine running the swxtch-xNIC service.

To do this:

1. **Open** the `/etc/sysctl.conf` to begin editing.
2. **Add** the following lines:

```shell
net.core.rmem_default=26214400
net.core.rmem_max=26214400
```

**PLEASE NOTE**

The suggested kernel parameters above only optimize the receive buffer. If you need to increase the size of the send buffer, please contact support@swxtch.io.

1. Once the desired changes have been added to `/etc/sysctl.conf`, **save changes** and **exit**.
2. **Run** the following command to validate the change:

```shell
sudo sysctl -p
```

Example:

```shell
$ sudo sysctl -p
net.core.rmem_default = 26214400
net.core.rmem_max = 26214400
```

1. **Run** the following command to validate the rmem max.

```shell
sudo sysctl net.core.rmem_max
```

Example:

```shell
$ sudo sysctl net.core.rmem_max
net.core.rmem_max = 26214400
```

If the values are the expected ones, the kernel has been tweaked, and now users should do a test to validate transfers.