[Beowulf] odd vlan issue

[Michael Di Domenico]

i got roped into troubleshooting an odd network issue.  we have a mix
of cisco (mostly nexus) gear spread over our facility.  on one
particular vlan it's operating as if it's a hub instead of switch.

has anyone seen this before?  i bounced around the net, my issue
appears to be "unicast flooding", but the chief correction seems to be
adjusting the ARP/CAM timeouts.  but that hasn't working.

i'm sure this is a loaded question given none of you can see the
network, but i'm grasping at straws to come up with a reason why this
is happening.

what's weird is we have two dozen other vlans, which aren't affected.
i cannot locate a difference in the config on the switches.

any thoughts are appreciated at this point