Spanning Tree - Type P2p

[RS19]

I have the below command.

The switch port  type is P2p. It is not P2p edge. Because of that this port is part of STP topollogy change. Which means whenever the switch port goes up/down STP topology change notifications are sent.
This port server is connected.
So I dont want any STP topology change notifications to be sent. Any configuration change I can make to achive this. (By changing to access port, this can be stopped, but I need this port to be trunk)

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interface GigabitEthernet1/0/1
switchport trunk allowed vlan 630
switchport mode trunk
arp timeout 300
spanning-tree portfast
spanning-tree bpduguard enable
end

SW01#show spanning-tree int gigabitEthernet 1/0/1

Mst Instance        Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
MST0                Desg FWD 20000     128.2    P2p 

[RS19]

In addition, below is the existing configuration of that port.

switchport trunk allowed vlan 600
switchport mode trunk
arp timeout 300
spanning-tree portfast
spanning-tree bpduguard enable

[MHM Cisco World]

Let me check this

MHM

[Giuseppe Larosa]

Hello @MHM Cisco World ,

the OP @RS19 is using MST

>> MST0 Desg FWD 20000 128.2 P2p

Hope to help

Giuseppe

[RS19]

So can i add the below command to address my requirement.

spanning-tree portfast edge trunk

[Giuseppe Larosa]

Hello @RS19 ,

>>

So can i add the below command to address my requirement.

spanning-tree portfast edge trunk

yes in interface mode as we have discussed before.

Hope to help

Giuseppe

[MHM Cisco World]

I already run and immediately the port turn from 
p2p -> p2p edge 

NOTE:-
some SW support this command 
spanning-tree portfast edge trunk
other support below 

spanning-tree portfast  trunk

MHM

[MHM Cisco World]

spanning-tree portfast  trunk

MHM

[MHM Cisco World]

spanning-tree portfast  trunk

MHM

[M02@rt37]

Hello @RS19 

To prevent STP topology change notifications from being sent when your trunk port goes up or down, while keeping the port in trunk mode, you should use the `spanning-tree portfast edge trunk` command under the interface configuration. This command enables PortFast on the trunk port, treating it as an edge port, which ensures that the port bypasses the usual STP states and does not trigger topology changes when the link state changes. This is particularly useful for ports connected to servers or other non-STP devices, as it allows the port to immediately enter the forwarding state without affecting the overall STP topology. Additionally, you should keep `spanning-tree bpduguard enable` configured, as this protects the network by shutting down the port if a BPDU is received, preventing potential loops. Depending on your IOS version, the command might be `spanning-tree portfast trunk` or `spanning-tree portfast edge trunk`, and either variant will achieve the desired effect, maintaining the trunk configuration while stopping unnecessary STP notifications.

[RS19]

Thanks.

U mentioned " `spanning-tree portfast trunk` or `spanning-tree portfast edge trunk`,

I already have the below commands

switchport mode trunk
spanning-tree portfast


Is the above 2 commands equal to the command "spanning-tree portfast trunk" ?

[MHM Cisco World]

Is the above 2 commands equal to the command "spanning-tree portfast trunk" ?

Big NO' it totally different

MHM

[Giuseppe Larosa]

Hello @RS19 ,

>>

I already have the below commands

switchport mode trunk
spanning-tree portfast

>> Is the above 2 commands equal to the command "spanning-tree portfast trunk" ?

No, they are not equivalent the commands spanning-tree portfast trunk or spanning-tree postfast edge trunk are more specific and their purpose is to enabled P2P Edge on a port that is configured as a trunk and it is operating as a trunk.

Hope to help

Giuseppe

[M02@rt37]

@RS19 

The commands switchport mode trunk and spanning-tree portfast, when used together, do enable some level of STP optimization on a trunk port by allowing the port to bypass the traditional STP states and immediately enter the forwarding state. However, these commands do not fully achieve what spanning-tree portfast trunk or spanning-tree portfast edge trunk are designed to do. The latter commands are more specific and instruct the switch to treat the trunk port explicitly as a P2P edge port within the STP framework. This distinction is important because it ensures that the port is recognized by STP as an edge port even though it is configured as a trunk, which is particularly relevant in preventing STP topology change notifications when the port's link state changes, such as when a server or other non-STP device is connected.

Using spanning-tree portfast trunk or spaning-tree portfast edge trunk provides a more accurate and reliable configuration for scenarios where the port must operate as a trunk while also being treated as an edge port by STP. Therefore, while the combination of switchport mode trunk and spanning-tree portfast does provide some level of STP efficiency, the more specific spanning-tree portfast trunk or spanning-tree portfast edge trunk commands are recommended for a more precise and effective configuration on trunk ports that connect to devices not participating in STP.

[RS19]

My vendor is suggeting to use the below command.

spanning-tree portfast trunk

Any difference between this command and "spanning-tree portfast edge trunk"

[RS19]

My vendor is suggeting to use the below command.

spanning-tree portfast trunk

Any difference between this command and "spanning-tree portfast edge trunk"

[MHM Cisco World]

I already suggested this in my previous comments

And there is no difference at all

It just IOS ver. Command different, 

MHM

[paul driver]

Hello

---

@RS19 wrote:
This port server is connected.
So I dont want any STP topology change notifications to be sent. Any configuration change I can make to achive this. (By changing to access port, this can be stopped, but I need this port to be trunk)

nterface GigabitEthernet1/0/1
switchport trunk allowed vlan 630
switchport mode trunk
arp timeout 300
spanning-tree portfast  <---- applied but will not be used as interface is in an administrative mode of trunk
spanning-tree bpduguard enable <----as its  applied to the interface, the  port will err disable if bpdu's are received 

---

Trunks will participate in stp listening/learning states, or proposal/syncing, if you wish for this interface to bypass those states you'll need to apply port-fast trunk as suggested by others.

Note- If you are using MST, then it is recommended NOT to manually prune any vlans on the trunks, Unlike PVST+/RSTP which are per-vlan spanning-tree which will allow you to prune trunks for certain LB criteria or vlan isolation, MST is per-instance spanning-tree meaning a single logical stp instance for all vlans, runs over the trunk(s) so pruning a vlan off a mst trunk can cause unwarranted l2 issues as those vlan(s) you wish to prune are part of that single logical instance

suggest port cfg: 
interface GigabitEthernet1/0/1
Description server
switchport mode trunk
spanning-tree portfast edge trunk  
spanning-tree guard root

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 @MHM Cisco World  wrote:

Which port effect by topology change? 
Any port connect to host with or without portfast not effect.

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My understanding this is incorrect, any port without portfast applied stp changes WILL be seen as/when that portt transisions up/down, hence it is recommended to assign all edge ports to go straight into a a forwarding state (portfast)