Link Aggregation (also referred to by the terms Port Bonding, Port Trunking, Link Bonding, to mention a few) is the process of combining multiple physical links (ports in case of switches) to form one logical link, for purposes of increasing total available bandwidth, performance and reliability. Link aggregation is most commonly used to link bandwidth intensive devices (such as servers) to the backbone of a network or for connecting core switches with distribution switches, to extend the reach of a network.
The E8, E24 and E48, all support link aggregation, using LACP. Through Datto Networking you can configure between 2 and 8 ports to be part of a single Link Aggregate Group (LAG) and you can have up to 4 such active groups configured on a single switch, concurrently.
Setting up a Link Aggregate Group (LAG):
To configure an LAG on switch, follow these steps:
1. Log into your Partner Portal account and the specific network that is managing your switches
2. Go to the Manage > Switches Page and click on the name of the specific switch you'd like to set up link aggregation on, to bring up its configuration pane.
3. Once in the configuration pane, select the ports you want to aggregate by checking the boxes on the left most column of the specific ports (example below is setting up a LAG with ports 3 and 4)
4. Once you are done selecting the ports of the LAG, click on the blue "Aggregate" button, up top to form your first Link Aggregate Group (Group 1). Note that the ports that are part of this LAG are clearly indicated as "Group 1" in the Link Aggregation column, with a common color (Red in this case).
5. You can then choose to create a second LAG in a similar fashion and so on (up to 4 LAGs are allowed). And you can have up to 8 ports per LAG (example below shows Group 2 has 4 ports - 1, 6, 8 and 10)
6. Successive LAGs are indicated with different colors (Red, Blue, Green and Orange)
7. If you made any other changes (besides Link Aggregation) to the switch pane, they would need to be saved by clicking the save button. It is a good idea to hit save anyway, just to be sure.
Splitting a Link Aggregate Group (LAG):
To split on or more links away from an LAG, simply click on the port(s) that you want to remove from their LAGs and click the "Split" button, up top. You'll notice that the Aggregate button changes to Split, when you select one or more ports that are already part of an LAG.
You can also split ports from multiple different LAGs, all at the same time, with one single click of the button!
1. When you aggregate ports together, if any of those ports were previously powering a PoE device, PoE will be disabled on them and will need to be re-enabled if required, once the LAG is torn down. You'll notice that the PoE configuration options for all ports in an LAG are also be disabled.
2. The port settings of the lowest numbered port will always be used for the LAG. The Port settings for remaining ports will be disabled.
3. Rate limiting is not supported on aggregated ports.
4. If you split even one of the ports from an LAG that has only two ports as members of the group, the entire LAG is torn down.
5. Link Aggregation is done using LACP, so it requires that the device (typically a server or another switch) plugged in on the other end is also LACP capable.