Unable to Create Network Namespace

Last Updated At: 2025-10-21 09:10:00

Problem Description

When performing a command to create a new Network Namespace, the command gets stuck and cannot continue. Dmesg message prompt: "unregister_netdevice: waiting for lo to become free. Usage count = 1"

Causes

This problem is a kernel bug. Currently, the following kernel versions have this bug:

Ubuntu 16.04 x86_64 kernel version is 4.4.0--91-generic.
Ubuntu 16.04 x86_32 kernel version is 4.4.0--92-generic.

Solution

Upgrade the kernel version to 4.4.0--98-generic, which has fixed this bug.

Processing Procedures

Perform the following command to check the current kernel version.
```
uname -r
```
Perform the following command to check whether the 4.4.0--98-generic kernel version is available for upgrade.
```
sudo apt-get update
sudo apt-cache search linux-image-4.4.0--98-generic
```
If the following information is displayed, it represents that the version exists in the source and can be upgraded:
```
linux-image-4.4.0--98-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
```
Perform the following command to install the new version of the kernel and the corresponding Header package.
```
sudo apt-get install linux-image-4.4.0--98-generic linux-headers-4.4.0--98-generic
```
Perform the following command to restart the system.
```
sudo reboot
```
Perform the following command to enter the system and check the kernel version.
```
uname -r
```
If the following result is displayed, it represents the version update is successful:
```
4.4.0--98-generic
```