Setting Up a Link Aggregation
5 minute read.
In general, a link aggregation (LAGG) is a method of combining (aggregating) multiple network connections in parallel to provide additional bandwidth or redundancy for critical networking situations. TrueNAS uses lagg(4) to manage LAGGs.
You can lose your TrueNAS connection if you change the network interface that the web interface uses!
If your network changes result in lost communication with the network and you need to return to the DHCP configuration, you can refer to the information below to restore communication with your server. Lost communication might require an IPMI or physical connection to the system, and reconfiguring your network settings using the Console Setup menu.
To prepare before making changes:
Have the DNS name server addresses, the default gateway for the new IP address, and any static IP addresses on hand before making network changes. You only have 60 seconds to change and test new network settings before they revert to the current settings. For example, back to DHCP assigned if moving from DHCP to a static IP.
Back up your system to preserve your data and system settings. Save the system configuration file and a system debug.
Grab a screenshot of your current settings in the Global Configuration widget as a precautionary step.
Before making network interface changes:
- Stop running apps.
- Power off running virtual machines (VMs) and containers.
- Remove active NIC devices for VMs and containers.
Changing IP address(s) assigned to the primary interface can cause issues with access, so it is best to make changes outside normal working hours.
TrueNAS protects your connection to the interface by displaying the Test Changes option on the Network screen after you make and save changes to the network interface.
TrueNAS shows the unapplied changes widget above the Interfaces widget after saving network changes.
Click the Test Changes button to test access to the UI after making a change and before making it a permanent change. This safeguard is intended to prevent changes that can break access to the UI.
Revert Changes discards any changes made to the interface within the same 60-second period.
The test timer starts after you click Save on the Add Interface or Edit Interface screens. After clicking Test Changes, wait a few moments to give the interface time to initialize, and then refresh the browser until you see the Save Changes button or follow the steps below to test in a new browser tab. Click Save Changes to make the changes permanent.
To test the change in a different browser tab:
Click Test Changes.
(Optional) Click on 60 and enter a new number to change the time allotted to test the network change before changes automatically revert.
Immediately open a new browser window. Do not close the existing login session tab.
Enter the new IP address in the browser URL field of the new browser window, and press Enter. The TrueNAS login screen displays.
Enter your administrator login credentials to access the system.
Go to Network and click Save Changes to make the changes permanent.
If the timer expires before you save the changes, TrueNAS reverts to the settings before you made the change. Return to the original browser session, to re-enter your interface changes, click Save, then repeat the steps above.
If you cannot access the UI, return to the original browser session and click Revert Changes on the Network screen.
To set up a LAGG, go to Network, click Add on the Interfaces widget to open the Add Interface screen, then:
Select Link Aggregation from the Type dropdown list. You cannot change the Type field value after you click Save.
Name populates with the default name for a LAGG interface, bond1.
You cannot change the Name of the interface after clicking Apply.
Leave Define Static IP Addresses selected.
(Optional, but recommended) Enter any notes or reminders about this particular LAGG interface in Description.
Select the protocol from the Link Aggregation Protocol dropdown. Options are LACP, FAILOVER, or LOADBALANCE. Each option displays additional settings.
Select the interfaces to use in the aggregation from the Link Aggregation Interface dropdown list.
(Optional) Click Add to the right of Static IP Addresses to show additional IP address fields for each additional IP address to add to this LAGG interface.
Click Save when finished.
Test the network change when prompted.
