OPNSense 22.1 Performance Fix

OPNSense 22.1 is a fantastic release. But if you recently upgraded and experienced a significant drop in network performance, it may be due to a change in how traffic is handled for Virtual Instances.

 · 3 min read

Your Ancient PC Image by Herbert Aust from Pixabay


So you recently upgraded to OPNSense 22.1 and now your internet and network speeds have all but come to a halt? Well, this may be due to how OPNSense applies what they call Media settings. This refers to how the OPNSense software processes data packets for additional information you can refer to their excellent documentation on the subject.

The Problem

The issue occurs in environments where the network interface remains unassigned, usually due to a setup that leverages something called "vlans". To illustrate this concept, think of the following heierarchy:

-Network Card A
--vlan 5 (Assigned to Network Card A)

-Network Card B
--vlan 10 (Assigned to Network Card B)

In OPNSense, in order for you to use vlan 5 and 10 in the above example for your setup, you have to assign those vlans as interfaces in the firewall. This allows the software to know how to manage traffic you are intending to use in these vlans.

The software allows you to assign the vlans as interfaces without having to assign the "Parent Interfaces", which in this example are Network Card A and Network Card B.

In this scenario, with the latest version of OPNSense, this causes the "Media Settings" to no longer apply to the vlans, because the settings are now applied to the parent interface. Since in our case, the parent interface is not assigned as a firewall interface, the vlans do not get those media settings applied and cause the performance problems associated with those missing settings.

The Fix

To fix this issue, you simply have to assign the Parent Interface as an interface in the firewall. You then Enable the interface and save. Then restart your firewall for those settings to be applied.

Steps to Fix:

  1. Log into your firewall
  2. Click on Interfaces on the left side
  3. Click on Assignments towards the bottom of the Interfaces Menu
  4. In the main section of the screen you will see a New Interfaces section with a drop down.
    • Note, if you do not see this, that means you have no unassigned interfaces and your performance problems are most likely due to some other aspect of your setup.
  5. Choose your parent interface from the drop down and click "+" button on the right.
  6. Find the newly added interface in the list, usually named "Opt#" with a number picked from the next available number.
  7. Click on the name to open the settings.
  8. Rename the interface in the Description to something that makes sense to you.
  9. Check the "Enabled" checkbox.
  10. Check "Prevent interface removal"
  11. Click "Save"
  12. Click "Apply Changes"
  13. On the left side, click the Power menu
  14. Select Reboot and then click the "Yes" button.

After your firewall reboots, your performance should be back to the expected performance.

We hope this helps, please leave feedback. You can also check out this 10 minute video that walks through the issue in a bit more detail:

Watch OPNSense 22.1 Upgrade Broke My Internet


Nate is the Founder and CEO of Stapel, LLC