Link aggregation between two GS1900-24E switches

Mike_Fossati

Is it possible to use link aggregation (e.g. LACP) to connect two GS1900-24E switches witch each other?

#Biz_Switch_Mar_2019

Sakura_T

Why not.
Make sure you set LAG configuration correctly on both switches before actually connecting them, otherwise you'll have loops in the network.

Sakura_T

Why not.
Make sure you set LAG configuration correctly on both switches before actually connecting them, otherwise you'll have loops in the network.

Zoolook

Hi, I recently installed 2 switches of this exact model at home, on different floors and they're doing a good job while connected with 4 cables in a LAG between each other.

Now only the one in the ground floor is linked to the router and the internet, everything hooked up to the other one needs to use the LAG for connecting to the internet. As I still have a bit of physical room to wire a 5th cable between the floors, I'm wondering if I would connect the 1st floor Zyxel directly to the router, would that create a loop? If not, would that be of any benefit for connections directly to the router (internet)? 

Sakura_T

@Zoolook
Not sure exactly what you mean about the 5th cable, can you be more specific about your topology?
As I know, each LAG can support up to 8 ports in a group, which means you can include the "5th" port into the LAG and there will be no loop concern.

Zoolook

@TY9527
Oh, sorry, talking about the 5th cable can be misleading, indeed. It is not meant as part of the existing LAG which connects the 2 switches, it would be just physically routed along the other 4 but at the ground floor level connected to the router instead of the switch. So the topology would become a sort of degenerated (only by the physical shape) triangle consisting of the switches at 2 corners connected by the the 4 fold LAG as one "thick edge" and the router at the other corner, if I would add the "missing" edge (remember this corner is currently connected only to one of the switches by the LAG). So as this edge I would add to build the triangle would not be part of the existing LAG, it seems to me this triangle would then build a loop, unless something can be configured in order to avoid the loop.