I recently ran across an issue where the storm-control that was configured on my port-channel interfaces caused the physical interfaces to go into a suspended state.
Hardware: 3 stacked 3850 (IOS XE release 3.7.3E) access switches connecting to a Juniper legacy core and a new 6807-XL core
Interface/EtherChannel configuration:
interface GigabitEthernet1/1/1
description Uplink to 6807
switchport trunk native vlan 2248
switchport trunk allowed vlan 2106,2248,2510
switchport mode trunk
load-interval 30
auto qos trust
channel-protocol lacp
channel-group 1 mode active
service-policy input AutoQos-4.0-Trust-Cos-Input-Policy
service-policy output AutoQos-4.0-Output-Policy
end
interface GigabitEthernet2/1/1
description Uplink to 6807
switchport trunk native vlan 2248
switchport trunk allowed vlan 2106,2248,2510
switchport mode trunk
load-interval 30
auto qos trust
channel-protocol lacp
channel-group 1 mode active
service-policy input AutoQos-4.0-Trust-Cos-Input-Policy
service-policy output AutoQos-4.0-Output-Policy
end
interface Port-channel1
description Uplink to 6807
switchport trunk native vlan 2248
switchport trunk allowed vlan 2106,2248,2510
switchport mode trunk
logging event trunk-status
storm-control broadcast level 50.00
storm-control multicast level 50.00
storm-control unicast level 50.00
end
and
interface GigabitEthernet1/1/2
description Legacy Network
switchport trunk allowed vlan 12,30,50,111
switchport mode trunk
load-interval 30
auto qos trust
no cdp enable
channel-protocol lacp
channel-group 2 mode active
service-policy input AutoQos-4.0-Trust-Cos-Input-Policy
service-policy output AutoQos-4.0-Output-Policy
end
interface GigabitEthernet2/1/2
description Legacy Network
switchport trunk allowed vlan 12,30,50,111
switchport mode trunk
load-interval 30
auto qos trust
no cdp enable
channel-protocol lacp
channel-group 2 mode active
service-policy input AutoQos-4.0-Trust-Cos-Input-Policy
service-policy output AutoQos-4.0-Output-Policy
end
interface Port-channel2
description Legacy Network
switchport trunk allowed vlan 12,30,50,111
switchport mode trunk
logging event trunk-status
storm-control broadcast level 50.00
storm-control multicast level 50.00
storm-control unicast level 50.00
end
show etherchannel detail revealed that storm-control (broadcast suppression) was the issue:
Channel-group listing:
----------------------
Group: 1
----------
Group state = L2
Ports: 2 Maxports = 16
Port-channels: 1 Max Port-channels = 16
Protocol: LACP
Minimum Links: 0
Ports in the group:
-------------------
Port: Gi1/1/1
------------
Port state = Up Cnt-bndl Suspend Not-in-Bndl
Channel group = 1 Mode = Active Gcchange = -
Port-channel = null GC = - Pseudo port-channel = Po1
Port index = 0 Load = 0x00 Protocol = LACP
Flags: S - Device is sending Slow LACPDUs F - Device is sending fast LACPDUs.
A - Device is in active mode. P - Device is in passive mode.
Local information:
LACP port Admin Oper Port Port
Port Flags State Priority Key Key Number State
Gi1/1/1 SA susp 32768 0x1 0x0 0x132 0x45
Age of the port in the current state: 0d:00h:10m:48s
Probable reason: Broadcast suppression: Level of Gi1/1/1 is not configured. Level of Po1 is
50.00%, 50.00%.
<output omitted>
I ended up removing storm-control on both port-channels because I was working
in a limited window of time (cutover) and the link lights turned green and started passing traffic. I haven't been able to find much about this regarding why the interfaces went into a suspended state, as this is not the default behavior of storm-control or etherchannel (to my knowledge).
Also, interfaces Gi2/1/1 (to 6807) and Gi2/1/2 (to legacy) were not connected because not enough fiber was ran to accommodate this, but it is anticipated to happen in the future. So, I'm not sure if that
has something to do with it:
- Gi1/1/1 is part of Port-channel1 to the 6807 core
- Gi1/1/2 is part of Port-channel2 to the legacy core
The show etherchannel summary:
switch#show etherchannel summary
<output omitted>
Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
1 Po1(SU) LACP Gi1/1/1(P) Gi2/1/1(D)
2 Po2(SU) LACP Gi1/1/2(P) Gi2/1/2(D)
Any insight as to why Gi1/1/1 and Gi1/1/2 were in a suspended state because of storm-control would be appreciated. Thanks in advance.