[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 192.168.48.0/255.255.255.0. The address on the
CentOS side is 192.168.48.101, the address on the Linux end ought to be
192.168.48.100.

When I only bring up eth0.48 VLAN device with the IP=192.168.48.100 I have
no connectivity. If I bring it up along with eth0 with another VLAN 48
address assigned to it (for instance, 192.168.48.99) 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?

Thanks.

Boris.