Intel Network PCIe Issue

August 18, 2024

I recently encountered a puzzling network issue on an Intel Network VM. The kernel was up-to-date, and all configurations seemed correct, yet the network connection was dropping intermittently, causing a full network outage. In this blog post, I’ll walk you through the steps I took to identify and resolve the issue.

The Problem:

The network connection on the VM would drop randomly, causing a full network outage. Upon inspecting the system logs, I found the following error message:

[132915.070196] igb 0000:04:00.0 eth0: PCIe link lost

This error message indicated that the PCIe link was lost on the Ethernet interface (eth0). However, I couldn’t understand why this was happening, as the kernel was up-to-date and the hardware was functioning correctly.

Troubleshooting Steps:

To troubleshoot this issue, I followed these steps:

Verified Hardware Configuration: I verified that the hardware configuration was correct and that the Ethernet interface was properly connected to the switch.
Checked for Firmware Updates: I checked for firmware updates for the Intel Network VM, but there were no updates available.
Inspected System Logs: I inspected the system logs to see if there were any other error messages related to the network interface.

The Solution:

After some research¹, I discovered that adding specific kernel parameters might solve the issue. I added the following parameters to the kernel command line:

pcie_port_pm=off pcie_aspm.policy=performance

These parameters disable PCIe port power management and set the ASPM policy to performance.

Edit the /etc/default/grub file and add the following line to the GRUB_CMDLINE_LINUX variable:
```
GRUB_CMDLINE_LINUX="pcie_port_pm=off pcie_aspm.policy=performance"
```
run the following command to update the GRUB configuration:
```
sudo update-grub
```
I rebooted the system to apply the changes.
Note: Verify that the kernel parameters are being applied by checking the system logs or running the cat /proc/cmdline command.

Conclusion:

In this blog post, I demonstrated how I troubleshooted and resolved a mysterious network issue on an Intel Network VM. By adding specific kernel parameters to the GRUB configuration, I was able to resolve the issue with the PCIe link and restore network connectivity.