cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
6965
Views
0
Helpful
8
Replies

How to Stop Topology change notification?

sachin.tambat
Beginner
Beginner

Hi,

Want to know how can we stop topology change notification from specific network switch connected (Switch-Switch) over trunk port?

I used the spanning tree portfast trunk command but its still show me in sh spanning  details as topology has changed

Is there any other way we can stop the TCN?     

8 Replies 8

cadet alain
Mentor
Mentor

Hi,

Why would you want to stop TCN BPDUs on inter switch trunk links? It's a very bad idea because you'll defeat the purpose of STP altogether.

Regards

Alain

Don't forget to rate helpful posts.

Don't forget to rate helpful posts.

Hi,

we have connected our acsess layer switches to meeting room switches in our organization,

People use to remove the trunk connection from meeting switches and its creating lot of TCN. So we want to STOP TCN only from meeting room switches as it causing lots of TCN please advice.

Hi,

so users disconnect from acces ports on meeting room switch ? if so then enable PortFast  on the meeting room switch with spanning-tree portfast default command in global configuration mode.

Regards

Alain

Don't forget to rate helpful posts.

Don't forget to rate helpful posts.

users are removing trunk connection..so is it anything that we can do on trunk? as i already used spanning-tree portfast trunk command on both access layer and meetin room switch but it wont worked.it still generating TCN.

donlindsay70
Beginner
Beginner

If you are trunking to the access switches then you will get TCNs when the access layer switches are disconnected. If you don't need multiple vlans for your end users in this location then convert the trunk from the upstream switch to an access port and connect your downstream access switch to that port.

You will need to check the layer 2 port security on your upstream switch and be aware that you are more susceptible to L2 spanning tree issues if the users get creative with patching. Best to educate the end users on leaving the infrastructure as they found it.

Sent from Cisco Technical Support iPhone App

Is there anything can be done on trunk of both switch which can avoid TCN? as if i will be doing upstream  as access port then i can not manage the meeting room switch as it has different management vlan.

Guys can you reply on this?

Do you have the option of running two physical cables to the access switch in the meeting room?

If so, you can run two different access mode interfaces in two different VLANs. (One for management and one for data)

If this is not possible, I am not sure what your best option is.. if you REALLY want to filter out the TCN BPDUs even though I do not recommend it, you could probably make a MAC address ACL on the upstream switch and filter them out.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: