Do switch SG300 and SG200 support multiple VLAN on port channel ?

[manh dung]

I am using SG300 - 28 ports as core switch and SG200 - 26 ports as distributed switch. I want to establish port channel between distributed switch and core switch. The port channel will act as trunk port to carry multiple VLAN. I tried to configure LAG on SG300 but when I added port into LAG, I saw error "Port gi19 belongs to a VLAN..". I also saw the same error on switch SG200. I think switch SG300 and SG200 don't support multiple VLAN on LAG. Is it correct ?

[Dirk Dittert]

No, this is not correct. I have at least one SG300 that has a LAG that carries multiple VLANs. If I remember correctly, you have to do the following:

1. remove all VLANs from the ports of the LAG (not sure if you need to set the port mode to General as well)
2. create a LAG
3. Re-add the VLANs to the LAG. 

Hope that helps.

[manh dung]

I have tried it. I can add port without vlan into LAG but then I cannot add vlan into LAG. All port of LAG is disabled in port vlan membership.

I think it is impossible. This is some text from admin guide of cisco sg300:

To add a port to the LAG, it cannot belong to any VLAN except the default VLAN.

[Dirk Dittert · Accepted solution]

That is correct. Ports that are part of a LAG can't be assigned to VLANs anymore. However, you can assign the VLAN directly to a LAG. 

For example: you can go to the Port VLAN Membership page and then you need to switch from ports to LAGs. At the top of the page, there's a line that reads Filter: Interface Type equals to Port. You need to choose LAG instead of Port and click on Go. You'll then see all LAGs and the VLANs that are assigned to them. 

[manh dung]

It is amazing ! It works. Your answer is very helpful. Thank you very much.

I have other question. Does switch SG-300 just support 8 LAGs. Is it possible to extend LAG management table ?

[Dirk Dittert]

Exactly the question I was asking some time ago :-)

The SG300 series supports (I guess mainly for marketing purposes) only 8 LAGs. SG500 series supports up to 32 LAGs. The limit might be higher on "real" IOS switches.

I do understand the reasoning behind this, though: The SG300 is mainly marketed as layer 2 Access switch. In this case you have many clients (i.e. end user devices). Their traffic will be forwarded to switches on the distribution layer (layer 3 switches that route and filter on IP level). Those distribution layer switches can then be connected by LAGs (for redundancy and capacity) to your access switches. Usually, one or two such LAGs should be enough.

8 LAGs might be limiting if you're using the SG300 series for something like a top of rack switch where you're connecting servers with multiple redundant connections. But for that use case there might be other setups to increase redundancy without creating a LAG on the switch. This is also important because the SG300 series does not support stacking. This means, that all ports of your LAG (i.e. multiple redundant connections) will then need to terminate on a single point of failure (i.e. SG300 access switch). 

If you just need more capacity, I'd always go with 10GBit ethernet than with multiple cables.

[manh dung]

Thank you, Dirk Dittert

I am using SG-300 as core switch for network office. I will consider your recommendation :)