STP issue

[prspth]

Hello,
I'm trying to run a lab with two switches connected in a loop as follow:

switch1[0]="A"
switch1[1]="B"
switch1[image]="kathara/base"

switch2[0]="B"
switch2[1]="A"
switch2[image]="kathara/base"

I'm using brctl to enable stp and both switches think they are the roots though I can see the stp traffic on both networks. It looks like both switches are ignoring the stp messages. Could it be because the containers should be connected by veth?

[tcaiazzi]

Dear @prspth,

Thanks for reaching out!

Historically, it is not possible to make STP network scenarios, since with the old network plugin collision domains were implemented through Linux Bridges, that catch STP packets, influencing the algorithm.

However, with the new network plugin, based on VDE, it should be possible to use STP. Indeed, the VDE plugin does not affect traffic in any way.

We never tested it as we released the new plugin, but I created an example scenario with the same loop you provide, and it seems to work.

Here is the example: stp.zip

This is the network topology:

This is the STP status on both the switches:

On switch2 we have that eth0 is in blocking state, so it seems to work.

Please let me know if this helps and if the example works properly.

Thanks!

[prspth]

Dear @tcaiazzi,
Thanks for your quick reply and the scenario. I've checked in my kathara settings the Docker Network Plugin is set to kathara/katharanp_vde and it is. I ran your scenario and unfortunately switches are ignoring each other:

root@switch1:/# brctl showstp br0
 bridge id		8000.0e0cda40065c
 designated root	8000.0e0cda40065c
root@switch2:/# brctl showstp br0
 bridge id		8000.26cd05fabfac
 designated root	8000.26cd05fabfac

Here are the output of kathara check:

*	Current Manager is: Docker (Kathara)
*	Manager version is: 20.10.22
*	Python version is: 3.11.7 (v3.11.7:fa7a6f2303, Dec  4 2023, 15:22:56) [Clang 13.0.0 (clang-1300.0.29.30)]
*	Kathara version is: 3.7.1
*	Operating System version is: macOS-13.1-arm64-arm-64bit
*	Trying to run container with `kathara/base` image...
Deploying devices...|##################################################################| 1/1
*	Container run successfully.
Deleting devices...|###################################################################| 1/1

Is there anything else I should check? Thanks!

[tcaiazzi]

Dear @prspth,

I suspect it is something related to your environment, since on my side I have:

root@switch1:/# brctl showstp br0
br0
 bridge id		8000.0eb47daf56a0
 designated root	8000.0eb47daf56a0
...
root@switch2:/# brctl showstp br0
br0
 bridge id		8000.12689d22dc1d
 designated root	8000.0eb47daf56a0
...

On which platform are you performing the test?