Highlighted
zzmyers
1 Nickel

Configuring a Fiber Ring on N3024F

I have a perimeter fiber ring which connects about 20 switches to my Dell N3024F. This ring runs the perimeter of our property which is about 1.5 kilometers in length and runs the perimeter security cameras and other devices. There is no easy way to connect in star topology. Right now, I only have one side of the ring plugged in as if I plug in the other side, loop protection shuts down the ports.

I really need the ring as we have a lot of thunderstorms and I get switches or breakers knocked out way to often and want to have the redundancy of the 2 paths back to the switch.

I know a ring should be possible to configure, but I need a tutorial or step-by-step instructions on how to set this up on the N3024. The 1600 page manual is a bit daunting and I am not an expert on Dell switches. Anything anyone can point me at on how to configure this would be appreciated.

0 Kudos
7 Replies
Moderator
Moderator

Re: Configuring a Fiber Ring on N3024F

Hi,

Is there more than one connection between the switches? Something is triggering the spanning tree to shut down ports. It should shut down one of the ports in the ring but it should be accessible over the active connection.  Can you connect it and use the show spanning-tree blocked ports command to see what it is blocking? It is possible that with that many switches it may be timing out spanning tree.

Thanks,
Josh Craig
Dell EMC Enterprise Support Services
Get support on Twitter @DellCaresPRO
0 Kudos
zzmyers
1 Nickel

Re: Configuring a Fiber Ring on N3024F

Hi Josh,

Thanks. I inherited this switch as supposedly unconfigured, but was told that the ring worked at some point in the past. I really don't know how much of that to believe as the original installers were not very good. So, I am unsure if the spanning tree is even set up correctly for this. I will do the test you suggest at a time when it is least disruptive. But I was wondering if there is something I that would give me a walk-through on what the settings should be so as to hopefully avoid shutting down the ports. Or at least give me a better chance to avoid that outcome.

Thanks,

Steve

 

0 Kudos
Moderator
Moderator

Re: Configuring a Fiber Ring on N3024F

Hi,

If you are needing step by step, the best option is our deployment services. https://www.dell.com/en-us/work/learn/by-service-type-deployment  

Thanks,
Josh Craig
Dell EMC Enterprise Support Services
Get support on Twitter @DellCaresPRO
0 Kudos
zzmyers
1 Nickel

Re: Configuring a Fiber Ring on N3024F

So, I tried connecting the ring and the entire switch instantly went into blocking mode -- at least I could not access anything through the network and everything connected to the switch went down.

As far as I can see, all of my Dell switches are in RSTP mode. I checked one of my perimeter switches in the ring and it was set to MSTP mode. I am assuming that could cause a problem. In checking the manuals, it looks like most of my perimeter switches are running in MSTP mode -- they are Planet industrial switches, a couple of IFS industrial switches and a few unmanaged switches. Everything is currently running on VLAN 1.

I would assume that all switches should have same STP mode. Is there anything I should know when mixing and matching switches like has been done here?

Steve

0 Kudos
Moderator
Moderator

Re: Configuring a Fiber Ring on N3024F

I would try setting the same spanning-tree mode. Usually different brand switches work together fine, if the switch is not accessible it sounds more like spanning-tree is not working and it is creating the loop.

Thanks,
Josh Craig
Dell EMC Enterprise Support Services
Get support on Twitter @DellCaresPRO
0 Kudos
zzmyers
1 Nickel

Re: Configuring a Fiber Ring on N3024F

Thanks. Makes sense. I will reconfigure and try again.

0 Kudos
zzmyers
1 Nickel

Re: Configuring a Fiber Ring on N3024F

I reconfigured the switches on the ring which I could -- I found out most of the switches are not managed. I plugged in the 2nd side of the ring and everything went down again. I was plugged in with a console cable and ran the "show spanning-tree blockedports" command and it showed no ports were blocked. I looked at the switch and both link and activity lights were on solid for the 2 ports on the ring.

Seems something is not configured right. Here are the global settings:

image.png

Should the ports for the loop be set up as a LAG? Or is there something else I am missing?

Steve

0 Kudos