VLAN Confusion around passing through PPPoE from Draytek Modem to OpenWrt Router

Hey, I hope you can point me in the right direction here. I'm an IT professional, but networking overwhelms me, it's just a whole different beast. But, I'm eager to learn. I just feel like I'm missing a core framework in my mind that helps me grasp it all..

Anyway, it's probably a very basic issue, but bloody hell..

So, my home internet is PPPoE VDSL2 with VLAN tag 7. Currently using a cheap TP-Link modem router.

Before me I have a Draytek Vigor 165 modem and a Cudy W3000 with the latest stable OpenWrt. My plan is to use the Draytek as bridge, passing through DSL (connected to Draytek WAN) to the Cudy (from Draytek LAN1 to Cudy WAN), where the PPPoE dial-in will take place. Draytek gets 192.168.2.1, Cudy gets 192.168.1.1 and has DHCP enabled for 192.168.1.1/24 to serve the clients.

Does that look alright to you so far? :slight_smile:

Now I'm stuck at the whole VLAN tagging situation. Do I enable VLAN on the Draytek, but don't tag it? Do I enable and tag it with 7 at the Draytek? Do I configure Cudy WAN without any VLAN settings when it's already tagged at the Draytek? Do I configure two VLANs in Cudy, one of them tagged 7 for Cudy WAN and one of them tagged ??? for Cudy Lan 1-3 & WiFi? Are there multiple ways to do it? Are there performance differences?

Like, I know the very basics of what VLANs are, but.. feeling like I'm in over my head, which rarely happens. Normally I find some way to make sense of complicated situations, but here.. not really.

Appreciate any help!

PS: What doesn't help is the fact that the Drayek offers "Bridge Mode" twice, once in the Operation Mode settings, and once in MPoA settings that aren't available when you put the Operation Mode in Bridge Mode..

The packets going into the DSL line usually need to be tagged. The modem usually can handle adding and removing tags as packets pass through so that the Ethernet connection to the router is untagged. This of course simplifies router configuration.

If you need tagged pppoe packets on the Ethernet cable this is not complicated to do in the router as it appears the WR3000 is a typical DSA model. Change the wan interface's Device from wan to wan.7 for example if the tag needs to be 7.

Even better, if the modem supports it, have the modem terminate the pppoe connection internally and bridge ipoe (i.e. user TCP/UDP connections as plain layer 3 over Ethernet) to the router. Terminating pppoe can be CPU-intensive when there is no hardware accelerator for it.

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Thanks so much for the reply!
The Draytek doesn't seem to support IPoE, at least I don't see options relating to it in the GUI, so I guess we can bin that one.

The packets going into the DSL line usually need to be tagged. The modem usually can handle adding and removing tags as packets pass through so that the Ethernet connection to the router is untagged. This of course simplifies router configuration.

So in this case I would enable tag insertion on the modem (there's Customer tag and Service tag, I'm guessing I need the Customer one in my case?) and configure WAN on the router as PPPoE connection with my credentials and don't configure anything relating to VLANs there?

If you need tagged pppoe packets on the Ethernet cable this is not complicated to do in the router as it appears the WR3000 is a typical DSA model. Change the wan interface's Device from wan to wan.7 for example if the tag needs to be 7.

Oh so this isn't done by creating a VLAN device? And I wouldn't need to do this at all if I enabled tagging on the modem, yes?

Thanks again!

I'm going to guess that Customer Tag is on the Ethernet cable (facing the customer) and Service Tags are on the DSL line (facing the service provider). So you would set Service Tag to 7 and Customer Tag to none.

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Thanks man, I'll try the configuration in the next days and report back :slight_smile:

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You can do the tagging either on the daytrek modem by setting the customer tag or by using the described wan.7 (or however you wan Ethernet port is called in openwrt). I prefer the tagging inside the modem and doing pppoe stuff on the router.

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Thanks again! I managed to get it running by tagging in the modem and dialing in on the router.

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