Les and everyone, Thanks! I have just redone the whole setup and discovered the following: the problem appears to have been on the Cisco side all along. The default (natiive) VLAN on the trunk port was set to VLAN 3. Apparently, it had to be set to VLAN 1. Once I did it the port started to work exactly as expected, whether a VLAN is named or not! Problem solved! Thank you all very much again. This was an obscure one for sure. Cheers, Boris. On Mon, Jun 2, 2014 at 2:11 PM, Les Mikesell <lesmikesell at gmail.com> wrote: > On Mon, Jun 2, 2014 at 12:55 PM, Boris Epstein <borepstein at gmail.com> > wrote: > > Hello everyone, > > > > Thanks for thoughtful and thorough advice. No luck so far, though. > > > > I have two VLAN's now - 0003 and 0004, named "vlan3" and "vlan4" > > respectively - and still for some reason the CentOS fails to recognize > them > > as one would expect. So I am puzzled as to what is still missing from the > > picture? Could the NIC itself (the hardware) introduce some undesired > > weirdness into the picture? > > You haven't given enough info for anyone to help. Can you post your > ifcfg-eth0 and ifcfg-eth0.3 files along with the error messages you > see if there are any? > > -- > Les Mikesell > lesmikesell at gmail.com > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >