WAN with VLAN? (AT&T Fiber True Bridge Mode)

Hi folks, I'm working on setting up my OpenWRT router (WNDR3800 w/ 18.06) with AT&T Fiber in the US, going for true bridge mode (idea from https://github.com/jaysoffian/eap_proxy ). The part in question for this post is that the router's WAN port is eth1 normally (not on a switch, it's a dedicated port). To make this work, I need to route my traffic to the internet over eth1.0 (VLAN 0 on eth1).

The good news is I have it working! But a couple warts remain:

  1. I'm not sure how to get OpenWRT to route my traffic over eth1.0 rather than eth1. I can manually get it going by deleting the default route and adding my new one ("ip route del ... eth1 ; ip route add ... eth1.0"). Can I somehow set a given interface to the default?

  2. I'm not sure how to get IPv6 working over eth1.0, but maybe an answer to the previous point above will point me in the right direction. When I use the AT&T provided router, I do have IPv6 working, so I'm sure the network supports it.

Thanks very much! I'm hoping to get it working, clean it up, and submit a patch + docs to make this easier for others.

VLAN 0 isn't really a VLAN, but indicates priority tagging -- see, for example https://en.wikipedia.org/wiki/IEEE_802.1Q#Frame_format

It's not unheard of that the "WAN" interface is VLAN tagged, but VLAN 0 doesn't seem right to me.

I agree VLAN 0 is weird and looks incorrect, but I think that's orthogonal to my question. Say it was some normal/valid VLAN (e.g. 3 for example). How do I get traffic routed to the internet over a given VLAN?

You define your "WAN" interface on eth1.NNNN and either apply DHCP or static addressing and routing to that interface, as appropriate (rather than to eth1 itself). You'll also need to adjust your switch so that it passes VLAN NNNN as tagged out of its WAN port (or whichever one you're using), as well as tagged to the internal port that eth1 is connected to.

I'm trying to wrap my head around this, too, but am much further behind in understanding it. I'm using a Linksys WRT3200ACM. So the ONT goes to the WAN port, and one of the LAN ports becomes dedicated for the AT&T residential gateway? In my case, an Arris BGW510.

Seriously, I'm totally lost how to get eap_proxy working

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@davygrvy I am having the same issue. I'd love some instructions on how to accomplish this.