X670G2 will not pass vlan traffic on a specific port

[AdmiralKirk]

I inherited an x670g2 when I took this job.  It is still on an older image (ExtremeXOS version 21.1.3.7) because I have too many other things to do.

There were ~10 vlans defined already, all of them tagged on the 5 ports that support our separate buildings on campus, as well as tagged on the ports connecting to our vmWare cluster.  DHCP comes from a Windows server in said cluster, with scopes defined for each building/vlan.  In the past year I've added 4 vlans successfully, but the one I'm trying to add now ("v27") just will not work.  

I've made the settings for v27 identical to v16 (my building) excepting of course the correct IP for v27 (192.168.27.1) and the correct port (port 11): tagging, ipforwarding. bootprelay, ports, ospf.  From my desk I can ping 192.168.27.1, the address of the v27.  SSH on the switch and i can ping 192.168.27.1 as well as 192.168.16.1 (my building's vlan). 

I am not getting any traffic to cross the switch.  I connect my laptop to port 11 with a static IP (192.168.27.32) and am unable to ping the switch.  The switch is also unable to ping the laptop.

More info:  about every 6 months this thing stops passing traffic for one or more vlans and I have to reboot it.  The time came around again and I just did that reboot last week, which was before trying to add this new vlan.

I am open to ideas and suggestions.  

[AdmiralKirk · Accepted solution]

After letting the problem simmer for a few days, and over the weekend, I realized just now where the root problem is:  me being dumb.  But honestly, the problem is that I set the tagging but did not have a tag-aware device at the other end to handle the untagging.  Put my IDF switch in place and bam!