Cannot pass single VLAN

[spgsitsupport]

Have few edge stacks (2920) connected to Core stack of Comware based 5900AF via single 10Gb fibre

All routing done by Core

Each stack have the same various VLANs defined (tagged and/or untagged ports)

On every stack every VLAN works. But on one stack a single VLAN does not work (all the other VLANs work fine on that stack)

I have same setup as everywhere, gbic port tagged on 2920, some copper ports on 2920 untagged.

From that 2920 stack I CAN ping Core IP of the VLAN in question and/or DHCP server, but plug in any device to an untagged port and nothing (no IP received, and if set static, no communication)

I have checked, rechecked, re-created, rebooted. Nothing.

Drives me totally insane. Anybody has any idea how to start tackling it?

Seb

[drk787]

Hi @spgsitsupport 

Can you share the configuration from the core and non working edge stack,the VLAN number, the interface number where you are connecting the PC on edge switch and testing.

[spgsitsupport · Accepted solution]

Most simple explanation. The fibre links between two cabinets were wrongly labeled.

So while config on the sattelite 2920 stack was correct, the port on core (as it was mis-labeled) was not tagged for the VLAN in question.

Ofcourse that would not work.

I do not send tagged VLANs on every link, only on the one that is needed

Once noticed & corrected, all works as expected

[parnassus]

Aruba side, show vlan port ethernet <interface-id> detail will easily save your day (the output should - I prefer...the output MUST - match the VLAN Membership of the peer port on the peer switch).

Such of a simple check and you will find the wrong thing immediately...provided that - as very first step - you have also checked that disabling the involved downlink port on the Core will stop a working ping running against the edge switch...or, in a more elegant way, provided that a show lldp info remote-show reports things as you expect, who is who and where it is.

[spgsitsupport]

Indeed, but I did NOT have any config issue on this satellite Procurve switch!

All was exactly as expected (and as it should be)

Iit was a single tag VLAN missing on core 5900F single switch port (as the fibre patch panel names were mislabeled)

So I could be checking the sattelite switch till forever

[parnassus]

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@spgsitsupport wrote: Iit was a single tag VLAN missing on core 5900F single switch port (as the fibre patch panel names were mislabeled)

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Indeed I wrote between brakets: the output should - I prefer...the output MUST - match the VLAN Membership of the peer port on the peer switch. Like for like.

Apart of having an uplink cable connected on the wrong port, that's a bad thing (due to mislabelling or whatever)...the VLAN taggings should always match at both ends otherwise, even if you're dealing with good and correct physical connectivity (uplink/downlink/patching), not matching (missing) VLANs will not be transported at all.

Glad you solved!

[spgsitsupport]

Ofcourse that VLAN must match on both ends

But in my case it was not easy to find (2 cabinets in same building, same patch pairs used for connecting both).

Just different port on a core. I only found it because I was using another fibre pair & the red light was simply not there