wpa_supplicant; wired auth and dhcp

[Alex Sharaz]

Hi All,

I've got a configuration issue which I'm hoping someone can help with.

I'm running Ubuntu 16.04 (VM) and using wpa-supplicant 2.5 to
authenticate to a wired switch port.
By default any device connected to a wired switch port gets placed in
vlan 4003. Once authentication occurs, the client is placed in a
different vlan.

What I've got in /etc/network/interfaces is

# The primary network interface
auto enp0s5
iface enp0s5 inet dhcp

wpa-driver wired
wpa-conf /etc/wpa_supplicant.conf

The problem is that before wpa_supplicant authenticates, the interface
has already got an IP address from vlan 4003, so the client ends up on
the correct vlan with the wrong IP address.

I can run dhclient -r ;dhclient <ethernet_interface>
but is there a more elegant solution ?
Rgds