Aggregate using 4-port in FG cluster and Cisco Catalyst

[FB]

I have an 802.3ad aggregate using 4-port in FG dual-node cluster and a Cisco Catalyst Cisco IOS Software Bengaluru, Catalyst L3 Switch Software CAT9K_IOSXE, Version 17.6.5, RELEASE SOFTWARE fc2

The current status is: In FG all 4 ports are in Up-Running-Active state

status up algorithm L4 lacp-mode active

But in cisco side, half of the ports are in SUSPENDED state

Why is that?

How to detect parameters that are not matching? 

FG support is limited to tell me that in FG side everything is OK and even sending diag and sniffer information, still, they can´t tell what´s could be wrong in Cisco Side

Here, an example, the S status of the port

101    Po101 SU       LACP        Gi2-0-44 w     Gi2-0-46 s

============================================================================

status: up
npu: n
flush: n
asic helper: y
ports: 4
link-up-delay: 50ms
min-links: 1
ha: master
distribution algorithm: L4
LACP mode: active
LACP speed: slow
LACP HA: enable
aggregator ID: 1
actor key: 17
actor MAC address: 48:3a:02:ed:c3:52
partner key: 101
partner MAC address: 8c:94:61:b0:e0:00

and all ports are OK as well

member: port1
index: 0
link status: up
link failure count: 0
permanent MAC addr: 48:3a:02:ed:c3:52
LACP state: established
LACPDUs RX/TX: 5596/5509
actor state: ASAIEE
actor port number/key/priority: 1 17 255
partner state: ASAIEE
partner port number/key/priority: 557 101 32768
partner system: 32768 8c:94:61:b0:e0:00
aggregator ID: 1
speed/duplex: 1000 1
RX state: CURRENT 6
MUX state: COLLECTING_DISTRIBUTING 4

[AEK]

Try do the same as in this tech tip.

https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-setup-LACP-between-FortiGate-and-Ci...

[yutanta5]

In my case I'm running A/P because I do not need the capacity of 2. What I ended up doing to fail over and fail back was to tell the units that they both should accept BPDU's. If you do not do this you will end up with a Fortigate blocking traffic while the ports are up ( spanning tree will kick in ).