Spanning Tree Questions

[david.sovereen@mercury.net]

(2016-05-23 09:38 EDT: I edited this post for clarity and additional information, so you may need to re-read it)

I am having difficulty getting my Netonix switches to speak RSTP with anything other than my Cisco switch, which is root.

I have Mikrotik switches/bridges speaking RSTP and when their traffic goes through Netonix switches to get back to the Cisco root bridge, the path cost does not increase and when I packet sniff for BPDUs, the Mikrotiks see BPDUs from the Cisco (root) but not from the Netonix (directly adjacent switch between the Cisco and the Mikrotik).

In my configuration, my Management VLAN is 10 (top VLAN on VLANs tab). Is that causing Netonix not to send out RSTP on VLAN 1 (second VLAN on VLANs tab)? If so, can that be fixed? RSTP BPDUs are supposed to be on VLAN 1 and it seems like they are not for me.

I should add that I even have a path that goes Cisco <-> Netonix (1) <-> Netonix (2) <-> Mikrotik, and in this case, the Mikrotik still sees BPDUs from the Cisco, the Mikrotik does not see any BPDUs from either of the Netonix switches, and the path costs are not increasing as the number of bridge hops increases. The Netonix switches don't even seem to see each other. For example, no matter what I set the path cost to on Netonix (1), Netonix (2) will always see the path to the Cisco through it as root. I haven't found a place in Netonix that reports the distance to root on each port, which would be helpful in troubleshooting this. Both Netonix switches have the Management VLAN as 10. However, VLAN 1 is untagged on the ports connected to the Cisco and Mikrotik RSTP switches.

Thanks,

Dave

[sirhc]

I have pinged Eric to look at your post, but it helps to know what firmware version you are using.

[david.sovereen@mercury.net]

We are running 1.4.0rc 25

[sirhc]

Can you also post up screen grabs of the VLAN and RSTP and Device/Configuration Tabs I am sure he will want to see them.

[david.sovereen@mercury.net]

How do I upload the images?
Dave

[sirhc]

How do I upload the images?
Dave

Right below the BLUE SUBMIT button there is an "Upload Attachment" link
You can upload all you need

[david.sovereen@mercury.net]

This switch sits between a Cisco switch off Port 1 and a Mikrotik off Port 2 speaking RSTP.

Port 2 is in Discarding mode and it should not be. It doesn't seem to be processing RSTP packets from the Cisco and Mikrotiks. Port 2 and Port 3 should be Forwarding/Designated if it were processing RSTP correctly. When I packet sniff on the Mikrotik off Port 2 of the above Netonix switch, I see BPDUs from the Cisco and no BPDUs from the Netonix.

This switch hangs off the above switch on Port 3.

I have to manually set the Path Cost on Port 1 to 1 in order for it to want choose Port 1 as the port to root. Really, Port 1 should be Forwarding/Root and Port 2 should be Forwarding/Designated if it were processing RSTP correctly.

Dave

[Eric Stern]

I'll also need a detailed network diagram to make sense of this.

[david.sovereen@mercury.net]

I'm getting a Netonix shipped to me so I can break it in a lab. I won't be able to confirm until I receive a Netonix in 1-2 days, but the setup will be:

Cisco switch with:

spanning-tree mode rapid-pvst
spanning-tree lan 1 priority 4096

Mikrotik-1

All ports in Bridge with mode=rstp and path cost 10 (default on Mikrotik)

Mikrotik-2

All ports in Bridge with mode=rstp and path cost 10 (default on Mikrotik)

Wire up as follows:

Cisco G0/1 <-> Mikrotik-1 ether1
Mikrotik-1 ether2 <-> Mikrotik-2 ether1

Mikrotik-1 will show ether1 as root port with path cost of 10

Mikrotik-2 will show ether1 as root port with path cost of 20

Now substitute Mikrotik-1 with Netonix switch with VLAN and STP settings as shown in screenshots (I'm guessing this is critical to reproducing the bug), moving cables from Mikrotik-1 ether1 to Netonix Port 1 and Mikrotik-1 ether2 to Netonix Port 2. (both units in screenshots have identical settings for Port 1 and Port 2)

Mikrotik-2 should show ether1 as root port with path cost of 20 (like before), but it will not. It will show ether1 as root port with path cost of 10, and sniffing on that port, which is connected to Netonix Port 2, will show BPDUs from the Cisco and none from the Netonix.

Note that I don't have a Netonix here to lab this out, but as soon as I do (1-2 days), this is what I will be doing. If you have the equipment, time, and willingness to lab this out sooner than I can, and confirm the problem, that would be great.

Dave

[Eric Stern]

Cisco switch with:

spanning-tree mode rapid-pvst
spanning-tree lan 1 priority 4096

I suspect this is at least part of your problem. PVST is a proprietary Cisco feature and doesn't work with any non-Cisco equipment.

I have a Mikrotik, but I don't have any Cisco equipment so i can't duplicate your setup exactly.