[CentOS] VLAN issue

Fri Jan 23 23:27:59 UTC 2015
Boris Epstein <borepstein at gmail.com>

Hello all,

I have a machine running Centos 6.6 connected to a port on a Cisco Catalyst
3750 series switch. That port is part of VLAN 48. I have VLAN 48 on the
CentOS machine too.

The IP network on VLAN 48 is The address on the
CentOS side is, the address on the Linux end ought to be

When I only bring up eth0.48 VLAN device with the IP= I have
no connectivity. If I bring it up along with eth0 with another VLAN 48
address assigned to it (for instance, I do have connectivity.

Also, strangely enough, sometimes to get things going I have to disconnect
the Linux host from the switch - physically detach the wire and reconnect
it again.

Be that as it may when I just bring up the VLAN by itself I have thus far
been unable to get anywhere.

Has anybody seen a situation like this? Does anybody have an explaination
for it?