We are using a set of stacked Dell N2024 switches as our top of rack switch.
We have WAN connectivity from our ISP configured on a trunk port and access ports connecting to a set of firewalls.
Connectivity had worked fine while the firewalls were configured as active-passive but after switching to active-active we have problems with WAN connectivity.
We were seeing the ports being blocked by spanning tree so we disabled spanning tree on the VLAN which the firewalls are connected.
We have a similar setup in another datacenter where disabling spanning tree fixed the issue but on these switches the ports remain down.

 

TOR#show interfaces detail Gigabitethernet 2/0/10

Port Description Duplex Speed Neg MTU Admin Link
State State
--------- --------------------------- ------ ------- ---- ----- ----- -----
Gi2/0/10 WAN  Full 1000 Off 1518 Up Down

Port Description
--------- ----------------------------------------------------------------------
Gi2/0/10 WAN 

Flow Control: Enabled
Port: Gi2/0/10
VLAN Membership mode: Access Mode

Operating parameters:
PVID: 494
Ingress Filtering: Enabled
Acceptable Frame Type: Admit All
Default Priority: 0
GVRP status: Disabled
Protected: Disabled

Port Gi2/0/10 is member in:

VLAN Name Egress rule Type
---- --------------------------------- ----------- --------
494 VLAN0494 Untagged Static

Static configuration:
PVID: 494
Ingress Filtering: Enabled
Acceptable Frame Type: Admit All

Port Gi2/0/10 is statically configured to:

VLAN Name Egress rule
---- --------------------------------- -----------
494 VLAN0494 Untagged

Forbidden VLANS:
VLAN Name
---- ---------------------------------

Port Gi2/0/10 Enabled
State: Disabled Role: Disabled
Port id: 128.63 Port Cost: 0
Port Fast: No (Configured: no ) Root Protection: No
Designated bridge Priority: 32768 Address: F8B1.567B.FF5E
Designated port id: 128.63 Designated path cost: 0
CST Regional Root: 80:00:F8:B1:56:7B:FF:5E CST Port Cost: 0
BPDUs: Sent: 2306541, Received: 0

TOR#show spanning-tree vlan 494

Failure Information
---------------------------------------
VLANs failed to be configured : 1
---------------------------------------
VLAN Error
---------------------------------------
VLAN 494 Neither PVST nor Rapid-PVST instance exists for this VLAN / VLAN range.