"A virtual LAN, commonly known as a VLAN, is a group of hosts with a common set of requirements that communicate as if they were attached to the same Broadcast domain, regardless of their physical location. A VLAN has the same attributes as a physical LAN, but it allows for end stations to be grouped together even if they are not located on the same network switch. Network reconfiguration can be done through software instead of physically relocating devices." (Quoted from wikipedia)
What you can do with VLAN support in dd-wrt:
- Create different subnets for each router's lan port
- Change lan/wan port order
- 802.1q tagging so that a single port can carry frames for multiple VLAN's
Here are some broad generalizations about what hardware is believed to be able to support VLAN's in DD-WRT currently:
Only Broadcom based devices, no Atheros or Ralink devices.
Only LAN ports can do VLAN's on devices with BCM4704 CPU due to the WAN port having a separate MII (connection to the CPU). See the discussion in this thread.
Any other devices that don't create vlan# interfaces by default.
If vlan# interfaces are created then they likely can be reconfigured and tagged using nvram settings as explained on the Switched Ports page because the VLAN GUI is unreliable on modern devices.
VLAN Support Tables
Some notes about the tables:
Port-based VLAN's means that you can reconfigure ports to be in different VLAN's. Port-based VLAN's do not confirm 802.1q VLAN support.
802.1q VLAN's means that you can tag VLAN's with 802.1q headers to create a trunk between two devices that carries frames for multiple VLAN's. 802.1q VLAN's confirm that there is also Port-based VLAN support.
Always put a Confirmation Link when confirming that there is ("Yes") or is not ("No") support for either type of VLAN support. If you can not link to any confirmation then put a question mark ("?") for the VLAN types that can't be confirmed.
Multiple links for the same model are encouraged to help provide better reference.
phuzi0n wrote: When you test VLAN's you need to try to reconfigure them with the nvram variables. Put a port into the WAN VLAN and see if it starts functioning as a WAN port, add a port to a new VLAN and after rebooting set up the VLAN with an IP and DHCP on the networking page, and if you have multiple VLAN capable routers then try to make a trunk between them with at least 2 tagged VLAN's on each and make sure both VLAN's can communicate with a single cable using the trunk ports.
Trunking is a rather high level concept and it hasn't really been explained in detail in any guides that I'm aware of so that might be tough to test yet. I hope I explained it decently on the switch ports page but I do plan on writing a guide to extend multiple WLAN's with a VLAN trunk. I'm just not sure how exactly I want to write it with all the variety of nvram variables that can exist and the nonfunctional VLAN GUI on all k2.6 builds...
I added some code for Giga switches to work with VLAN page, but need extensive testing. If you can help, please test this build on as many Giga routers - report success and/or right/wrong port mappings.