Spanning Tree Questions

[sbyrd]

I will ping Eric and see if he can contact you to arrange access to the switches to try and figure it out.

This may not be easy to tell from afar what they are doing wrong.

Thank you. I understand that is might not be possible to see their mistakes. However, right now it has been my word against their Cisco guy, and as you can guess he is not familiar with Ubiquiti or Netonix so he assumes the problem is all on my end. Also, I am not really all that familiar with Cisco outside of a very very basic knowledge of IOS.

[sirhc]

The only person that would be of any real help here is Eric.

I have asked him to get into contact with you and see about getting access to the switch to possible see why the CPU is shooting up. Maybe that would tell us something?

If I was there on site and had access to their gear as a tech I could probably figure out what they are doing wrong but not from afar.

I do know that we use RSTP all over the place on our network with Cisco gear and other brands and we have no issues but I know that fact is of no help for you here with the finger pointing.

[sirhc]

The problem is the Cisco's switches are using Rapid PVST, which is kinda like RTSP (actually more like MSTP) but is not compatible with other switches as it is Cisco proprietary protocol.

We looked into some advice on how to configure other switches to work with it, but still didn't work.

If we put in an option to transparently pass through BPDUs if STP is disabled would probably work, we are considering putting this feature in v1.4.X

Other option would have been to have them use industry standard RSTP which those switches would support.

[sbyrd]

The problem is the Cisco's switches are using Rapid PVST, which is kinda like RTSP (actually more like MSTP) but is not compatible with other switches as it is Cisco proprietary.

We looked into some advice on how to configure other switches to work with it, but still didn't work.

If we put in an option to transparently pass through BPDUs if STP is disabled would probably work, we are considering putting this feature in v1.4.X

Thanks sirhc. I was going to come on here and put update on this thread myself.

Thaks to Eric for taking the time to help me out on this today. Unfortunately because of how the customer has their stuff configured I will have to remove the Netonix switches from the mix. Love the switches, but I have to make good on the contract and provide them with a working link.

Next time I will do my due diligence and get some more detailed configuration information from the customer before I quote, configure, and install a private link.

[sbyrd]

Chris/Eric,

We tried turning on RSTP on the netonix switches and they said it was not working. However should we instead tried using STP? The following post on another forum (I may be misunderstanding) seemed to say that PVST+ compatibility is accomplished via STP on other switches?

https://support.avaya.com/forums/showthread.php?t=4474

"When PVST+ is configured, it uses by default, normal STP BPDU’s on VLAN 1 and PVST BPDUs for other VLANs. This allows a PVST+ switch to connect to a switch using IEEE 802.1Q spanning tree as a tunnels for PVST. PVST+ BPDU’s are tunneled across the 802.1Q VLAN region as multicast data. The single STP is addressed to the well-known STP MAC address 01-80-C2-00-00-00. The PVST BPDUs for other VLANs are addressed to multicast address 01-00-0C-CC-CC-CD.
Coming to the Native VLAN:
If you are not tagging the native VLAN from Cisco, then on the ERS4500 side, you need to have the port mode Trunk All and Untag PVID option enabled on the port and PVID on port is native VLAN of Cisco. Else this frames may get discarded."

Also should we have then possibly set my ports to instead of Untagged Vlan 1, Trunk 1-3999 and set them to either Tagged VLAN 1 Trunk 1-3999 or maybe Q in Q vlan 1? Cisco treats VLAN 1 differently than most other networking equipment.

[sbyrd]

Other option would have been to have them use industry standard RSTP which those switches would support.

I wish I could have had them done that. This facility or campus is one of many across the USA and I think Europe and they all use exclusively Cisco so they use Cisco exclusive features like Rapid PVST+. To change it here they would have to change it everwhere. or that is the line that their engineer told me. Basically they are subject to the design methods of corporate.

[sirhc]

"When PVST+ is configured, it uses by default, normal STP BPDU’s on VLAN 1 and PVST BPDUs for other VLANs. This allows a PVST+ switch to connect to a switch using IEEE 802.1Q spanning tree as a tunnels for PVST. PVST+ BPDU’s are tunneled across the 802.1Q VLAN region as multicast data. The single STP is addressed to the well-known STP MAC address 01-80-C2-00-00-00. The PVST BPDUs for other VLANs are addressed to multicast address 01-00-0C-CC-CC-CD.
Coming to the Native VLAN:
If you are not tagging the native VLAN from Cisco, then on the ERS4500 side, you need to have the port mode Trunk All and Untag PVID option enabled on the port and PVID on port is native VLAN of Cisco. Else this frames may get discarded."

Also should we have then possibly set my ports to instead of Untagged Vlan 1, Trunk 1-3999 and set them to either Tagged VLAN 1 Trunk 1-3999 or maybe Q in Q vlan 1? Cisco treats VLAN 1 differently than most other networking equipment.

Would be interesting to try if they were game.

[sbyrd]

I am going to see tomorrow when I am scheduled to remove the Netonix to see if they are willing to give it a quick try. According to the document Eric found http://www.alliedtelesis.com/userfiles/ ... o_REVB.pdf It should not be necessary. They should just have to change the VLAN 1 settings on the Cisco. However, based on my phone conversation I am not sure they understood it that way or made the change.

See these excerpts from the above link.

[sbyrd]

My gut tells me they will not give it a try as the link has not worked as advertised since it was installed a few weeks back.

[sbyrd]

Final update: I was not able to get them to try some other setting tweaks. I removed the Netonix from between the Cisco and the Airfiber and everything is working fine. No fault of Chris or Eric. It is just they way this client has their network designed.