LACP confusion

[ShaileshMdr]

Hi Community,

So I have a question whether this LACP will work or not. I need your views on this also is there any other way on how I can improve this redundancy.

I have 2 Cisco Switches (Stacked) acting as a link switch.

FGT is in HA (Active and Passive).

Here there are 4 ports that are members of a single port-channel in Cisco switch.

And whereas in FortiGate there are 2 ports each in LACP.

Will it work?

Regards,

Shailesh

[srajeswaran · Accepted solution]

The LACP link will be up, but there will be traffic issues. For example the switch can forward the traffic to passive node as part of load balancing , but passive node will drop the packets.

We can use "set lacp-ha-slave disable" on FGT, and make the LACP down on passive node, but this will influence the failover time and can cause traffic disruption.

Ideal would be to use 2 separate port channels on switch and fortigate nodes.

Ref: https://community.fortinet.com/t5/FortiGate/Technical-Tip-LACP-behavior-in-an-HA-cluster/ta-p/195163

[ShaileshMdr]

Ahh okay!

So I should be using 2 port-channels.

Example: In port-channel 1 both links for active FGT while port-channel 2 both links to slave FGT.

Regards,

Shailesh

[srajeswaran]

Hi@ShaileshMdr ,  that is correct.

[ShaileshMdr]

Hello @srajeswaran 

Thanks for the suggestion. Appreciate it!

Regards,

Shailesh