3504 Dynamic Interfaces / Physical Interfaces

[GRANT3779]

Hi Folks, 

In the past when working with WLCs the interfaces have always been configured as LAG / trunk with the dynamic interfaces/vlans all going through the same LAG.

Can I have say some ports configured in a lag and then the left over physical ports potentially used for a specific dynamic interface? E.G for a dmz

[balaji.bandi]

I take that as a separate segment, not you looking in exiting LAG, then you should be able to.

But again it depends on the use case.

[GRANT3779]

Yeah completely separate. Only traffic exiting out this interface would be a specific VLAN /SSID traffic. Everything else would exit the LAG

[balaji.bandi]

personally not implemented never come across this requirement, this is good requirement.

as long that VLAN untagged in LAG, Only Tagged other Port it should work.

here is the reference :

https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-vlan/68100-wlan-controllers-vlans.html

[Scott Fella]

Well, from what I know, you either use LAG or you don’t. You will not be able to define a port channel for a single port different from the other ports. Also the WLC uses the default src ip dest load balancing. For your use case, you should not use LAG but define the port for that traffic. This way your management and other traffic could be primary on port 1 and backup on port 2 and for your special interface you can have that primary on port 3 and if you wish to have redundancy use port 4 as backup.

[GRANT3779]

Thanks Scott, assuming if i went down that route using say port 1, this would still have the ability to carry multiple vlans? Not clued up on the inner workings of the WLC, does it tag traffic with the corresponding dynamic interface vlan before sending it out onto the attached LAN?

[Scott Fella · Accepted solution]

The answer is yes. When you disable LAG, when you create interfaces or edit already existing interfaces, you define what ports are used. Only one interface on the WLC can be set to native but not necessary. If you have more than one interface assigned to a port, then that port has to be connected to a trunk port. You might as well just connect to all trunk ports in case you want to adjust in the future. Vlan tagging is defined on the WLC and has to match on the switch port.