Hi All,
Today I encountered weird behavior on my switch when i configured through an interface template.
To my knowledge Spanning-tree portfast should be configured on the interface itself, and won't work when it is only present in the template. Therefor almost all switch models i know configure it automatically on the interface when you source a template with spanning-tree portfast configured in it.
Today wasn't consistent in this behavior on my stack switch.
the facts:
- stack switches are WS-C3650-48PD both running IOS 16.9.5
- template configuration
template PLACEHOLDER_NAME
storm-control broadcast level pps 1k
storm-control multicast level pps 2k
storm-control action shutdown
storm-control action trap
spanning-tree portfast
spanning-tree bpduguard enable
switchport access vlan xx
switchport mode access
switchport nonegotiate
load-interval 30
!
- Interfaces start configuration
interface GigabitEthernet1/0/45
switchport access vlan xx
storm-control broadcast level 5.00
storm-control multicast level 5.00
storm-control action trap
ip device tracking maximum 10
!
interface GigabitEthernet1/0/46
switchport access vlan xx
storm-control broadcast level 5.00
storm-control multicast level 5.00
storm-control action trap
ip device tracking maximum 10
!
interface GigabitEthernet2/0/3
switchport access vlan xx
storm-control broadcast level 5.00
storm-control multicast level 5.00
storm-control action trap
ip device tracking maximum 10
- behavior
I performed exactly the same action on both interfaces, removing the current configuration and adding 'source template PLACEHOLDER_NAME'. I want to point out that both interfaces hadn't have spanning-tree portfast configured yet.
the following commands were performed
Switch(config)#int ra g1/0/45-46
Switch(config-if-range)#source template PLACEHOLDER_NAME
%Warning: portfast should only be enabled on ports connected to a single
host. Connecting hubs, concentrators, switches, bridges, etc... to this
interface when portfast is enabled, can cause temporary bridging loops.
Use with CAUTION
%Portfast has been configured on GigabitEthernet1/0/45 but will only
have effect when the interface is in a non-trunking mode.
%Warning: portfast should only be enabled on ports connected to a single
host. Connecting hubs, concentrators, switches, bridges, etc... to this
interface when portfast is enabled, can cause temporary bridging loops.
Use with CAUTION
%Portfast has been configured on GigabitEthernet1/0/46 but will only
have effect when the interface is in a non-trunking mode.
Switch(config-if-range)#no switchport access vlan
Switch(config-if-range)#no storm-control broadcast level 5.00
Switch(config-if-range)#no storm-control multicast level 5.00
Switch(config-if-range)#no storm-control action trap
Switch(config-if-range)#do sh run int g1/0/45
Building configuration...
Current configuration : 140 bytes
!
interface GigabitEthernet1/0/45
source template PLACEHOLDER_NAME
ip device tracking maximum 10
end
Switch(config-if-range)#do sh run int g1/0/46
Building configuration...
Current configuration : 140 bytes
!
interface GigabitEthernet1/0/46
source template PLACEHOLDER_NAME
ip device tracking maximum 10
end
For some reason it does notify with the portfast warning as it should, but does not configure it on the interfaces itself. I was like, Ok, than I add it manually this time. But on another interface where i performed the same action it reacted differently.
Switch(config)#int g2/0/3
Switch(config-if)#source template PLACEHOLDER_NAME
Switch(config-if)#no storm-control broadcast level 5.00
Switch(config-if)#no storm-control multicast level 5.00
Switch(config-if)#no storm-control action trap
Switch(config-if)#no switchport access vlan
Switch(config-if)#do sh run int g2/0/3
Building configuration...
Current configuration : 169 bytes
!
interface GigabitEthernet2/0/3
source template PLACEHOLDER_NAME
spanning-tree portfast
ip device tracking maximum 10
end
No warning this time, but it did configure spanning-tree portfast on the interface.
I do encountered the spanning-tree portfast warning when using the range command on most of the switches and it always configures spanning-tree portfast as expected on the interfaces. This time it did not.
Is this a minor bug? Is it configuration order? I don't know.
It did not break anything and is just a minor problem, but I still want to point it out.
