This VLAN configuration is for the ZyXEL ES-2108 8 port switch. Using the VLAN
configuration below, port 1 remains the admin port, port 2 is the trunk port,
port 3 is for the WAN connection and ports 4-8 can be used for a DMZ.

Hope this helps some people out there.

vlan 1 
  normal "" 
  fixed 1 
  forbidden 2-8 
  untagged 1-8 
  ip address default-management 192.168.1.1 255.255.255.0 
exit 
vlan 101 
  normal "" 
  fixed 2-3 
  forbidden 1,4-8 
  untagged 1,3-8 
exit 
vlan 102 
  name DMZ 
  normal "" 
  fixed 2,4-8 
  forbidden 1,3 
  untagged 1,3-8 
exit 
interface port-channel 2  
  pvid 100 
  name TRUNK 
  vlan-trunking 
exit 
interface port-channel 3  
  pvid 101 
  name EXTERNAL 
exit 
interface port-channel 4  
  pvid 102 
  name DMZ 
exit 
interface port-channel 5  
  pvid 102 
  name DMZ 
exit 
interface port-channel 6  
  pvid 102 
  name DMZ 
exit 
interface port-channel 7  
  pvid 102 
  name DMZ 
exit 
interface port-channel 8  
  pvid 102 
  name DMZ 
exit