One or two LAG port-channel for 5508 v7.4 in HA setup?

[PeterJacobsen]

Hi group

I have a question regarding LAG in HA setup; do you configure two port-channel, one for each controller or, only one port-channel for both?

I have a stack of 3 x 3750x, and 2 x 5508 with each two Gigabit uplink in use.
Active controler (5508-1) is connected to stack switch 1 and stack switch 2.
Standby controller (5508-2) is connected to stack switch 2 and stack switch 3.

I cannot find any documentation or guidelines for configurations of LAG in HA setup.

P.S. my question is not how to configure LAG or LACP, it only if you use one port-channel consist of 4 gigabit ports, or you have two with each 2 gigabit port to each controller.

TIA,
Peter

[Stephen Rodriguez · Accepted solution]

You still need to have separate port channels for each WLC otherwise the switch would see both as up and send traffic to the standby

Steve

Sent from Cisco Technical Support iPhone App

[PeterJacobsen]

Thanks Stephen for your reply.

The switch doesn’t see which of the two port-channel that is on the active controller right?

If WLC01 is the active one in PO1 and standby is WLC02 in PO2, the MAC of the active controller (WLC01) will be sending on PO1.

When failover to standby, the MAC of WLC02 will be sending on PO2. As I see it, it is same IP address (management IP address of WLC01) but different MAC address – from WLC02.

So why could it not be one Port-channel, both controller will use one and same config when it become active?

TIA
Peter

[Stephen Rodriguez]

all ports will be up, and the switch will load balance across all ports, so if the WLC is in standby, the traffic that went there would blackholed.

HTH,
Steve

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[PeterJacobsen]

The right solution is two etherchannels.

BG,

Peter