AC56U / PPPoe, VPI/VCI

[funkytwig]

Hi, I am using a AC56U connected to a TP LINK 8817 in Bridge mode (so I can use DDNS/VPN). The issue is the AC56U does not seem to support PPPoA (witch makes is useless in the UK with a bridged modem). It also does not seem to enable me to input VPI/VCI, which potentially makes it doubly useless.

Or have I missed something.

I was getting the error "'The wireless router currently uses a private WAN IP address (192.168.x.x, 10,x,x,x, or 172.16.x.x). This router may be in the multiple-NAT environment and DDNS service cannot work in this environment.'' when I tried to use the 8817 in non bridged mode which is why I went to bridged mode. Is there a way to get the 8817 to work in non bridged mode (maybe with a static IP and no DHCP (and get rid of this problem)?

Regards,
Ben

 

[mreckhof]

I was writing a more detailed answer, but ran out of time. If you want the real details, reply back and i'll work on something.

Nutshell: You're used to an "All-In-One" device and now you've split it into pieces. At which point, you need to understand the pieces or you'll have a mess (like this).

1. When you connect using only your ADSL Modem + Router ONLY, what IP address is reported as it's WAN IP? Not the one your PC gets from DHCP, but what it itself reports as the WAN IP assigned to its PPPoA interface. You'll have to login to the modem to see this. Getting it from 'what is my IP address' websites won't give you the answer I'm looking for. Point in asking this is only to make sure that your ISP isn't using private address space on its WAN and then doing the translations someplace else as that'll throw off the whole rest of my answer.

I'm going to assume for now that it's giving you a registered IP address (something not in 192.168, 172.16-172.31, 10 space).

2. If you've chained the WAN link of your ASUS router to the LAN link of your ADSL+ Modem, and it's getting an address AT ALL without configuration, much less one that's in the 192.168, 172.16-31, or 10 space, it's very likely you didn't properly put the modem in bridge mode. Double check it. You'll know you did it because you'll think you just broke everything if you go back to using it as a normal ADSL Modem again.

3. The reason why you don't see VPI/VCI in the ASUS is because it's an Ethernet router, not an ATM router. That's why you have to have the ADSL Modem there. VPI/VCI is an ATM construct, and therefore, it is configured on the ADSL Modem. Once it's in bridge mode., it's probably the only configuration it'll ask for.

4. The reason why you don't see PPPoA on the ASUS is because, once again, it's an Ethernet router, not an ATM router. That's where the A in PPPoA comes from. Instead, if the ADSL modem is in fact in bridge mode, and you've connected its LAN port to the WAN port of your ASUS router, then you need to setup your ASUS router for PPPoE (since it's now being done over Ethernet). That'll then get sent over the Ethernet WAN interface on the ASUS, over to the ADSL router on its Ethernet LAN port, at which point, it'll get bridged over to the ATM port (its WAN port on DSL) and on to the ISP.

So now, you'll put in any PPP information the ASUS and it should connect. If it doesn't, there may be one other thing going on, and that's that the ISP may be 'MAC Locking' where it'll accept PPP connections from. If that's the case, you'll need to get the MAC address off of the ADSL modem and plug it in on the ASUS where it lets you do a WAN MAC Override. It's usually stamped on the bottom of the device but not always and not always the right one. Worst case, if you at least get this far, you may be able to call your ISP and see if they can reset it to your ASUSs MAC address.

At this point, you've now successfully split up the 'All-In-One' device into its components with the ASUS now handling the Layer 3 stuff.

The misconfiguration message should now be gone since the ADSL modem is now not trying to also do the functions you've moved to the ASUS device.

 

[mreckhof]

One last thing. Make sure you REALLY REALLY understand what you're doing here. Once you flip that thing to bridge mode, it's not easy for a non-network professional to do all the steps typically required to flip it back. So you will be dead in the water until you make the rest of it work.

Also, I was doing some additional reading on the topic and there may also be a dependency on what kind of equipment your ISP is using. This works for me, however, it's possible my ISP may be using different equipment with different protocol and bridging options than yours.

Good luck.

 

[funkytwig]

Thanks, I am actually know how to access the router in bridged mode, either using a static IP and connecting the router directly to the PC or through USB. I am fairly technical, have worked in IT for a while.

Not got access to the site for a bit (it is a small charity I am doing this for) and will try what you say but came up with a plan B. The 8817 is a ADSL modem I got to replace the one supplied by the ISP (Technicolor TG582n). I did not want to risk telneting in to the TG582n and setting it to bridged mode because if I screwed it up it leaved them without a internet connection. Plan B is go back to using the Technicolor TG582n and using its DDNS. It will involve telneting in and changing the DDNS provider but I am OK with this as its not as drastic as putting it in Bridge Mode.

I am then hoping if I tun off the DDNS on the ASUS I can get VPN server working on the AC56U. I have turned of as much as I can on the TG582n and put the AC56U in its DMZ (which seemed like a good idea). I may also need to do some port forwarding?

Looking at the 8817 manual in terms of plan A in the Quick Setup / Bridged mode The only thing it asked for is Encapsulation (1483 Bridged IP LLC is the default, manual does not say what other options are). I am hoping when this is done I can still set VPI/VCI and PPPoA in the Interface Setup->Internet page on the 8817 Web interface.

Thanks for your help.

Ben