Assistance Needed for Network Configuration: Removing ISP Router

[Lukapple]

Hello,

I recently switched from a coaxial connection to fiber optic. During the transition, my ISP provided me with two devices: one is an ONT (Innbox G23 NT GPON) and the other is a router (Zyxel VMG8623-T50B). The fiber optic cable connects to the ONT, and then the LAN output goes into the Zyxel VMG8623-T50B router, which then connects to my Zyxel USG Flex 500.

Initially, the ISP's router (Zyxel VMG8623-T50B) was in "router" mode, so I requested the ISP to switch it to "bridge mode." Their support team set the VMG router to bridge mode and provided me with a username/password for establishing a PPPoE connection, but it didn't work. I monitored the network packets (using Wireshark), and only the initial PADI packet was sent.

After multiple contacts with support, I encountered an employee who surprisingly gave me completely different instructions - I had to provide the MAC address of my Zyxel Flex 500 (which is likely registered on the ISP's side) and set up automatic IP (DHCP). There was no mention of a PPPoE connection.

This setup works now, but I want to completely eliminate the VMG8623-T50B router. When I connect to the VMG8623-T50B, I can only see basic settings (others are apparently hidden or locked). Among these settings, I see "WAN information" with the following connections listed:

• ETHWAN_VLAN3907 (IPoE)
• ETHWAN_VLAN3906 (PPPoE): not connected
• ETHWAN_VLAN1101 (IPoE)
• ETHWAN VLAN1201 (IPoE): Bridged, this is apparently used for the internet
• ETHWAN_VLAN1401 (IPoE)
  Two of these connections are used for IP telephony (which I do not use).

I am now wondering where the PPPoE connection is established, as it is not established on the Zyxel VMG8623-T50B (since it uses IPoE). Is it possible that the PPPoE connection is established on the ONT (Innbox G23 NT GPON)? Or could it be that the PPPoE connection is established somewhere on the ISP's side?

Would it be possible to completely remove the VMG8623-T50B router and connect the output from the ONT (Innbox G23 NT GPON) directly to my USG Flex 500?

I would appreciate any advice and assistance with the configuration. Screenshots are attached.

Devices:

• Innbox G23 NT GPON (ONT): datasheet attached
• Zyxel VMG8623-T50B: User Guide
• Zyxel USG Flex 500: Product Page

Thank you!

 

[L&LD]

Yes.

Remove the ISP router and connect your router directly to the ONT.

 

[Lukapple]

Yes.

Remove the ISP router and connect your router directly to the ONT.

That was the first thing I tried - I set my router to DHCP and connected the cable from the ONT to the WAN port. However, I did not receive an IP address.

Could it be that I need to configure a specific VLAN for this to work?

 

[L&LD]

I don't know what you've done to your router, nor am I familiar with that model.

I would power down the ONT (minimum 10 minutes). Reset the router, and power everything up, and try again.

An ONT is just an Ethernet WAN connection. Otherwise, it isn't an ONT.

If that doesn't work, you may need to contact the manufacturer of the USG Flex 500 for help in setting that up properly.

At this point, it just seems you've really messed up the router settings for no reason (and toggling settings isn't ideal for getting the router to do what the GUI is showing, sometimes).

 

[Barmynon]

That was the first thing I tried - I set my router to DHCP and connected the cable from the ONT to the WAN port. However, I did not receive an IP address.

Could it be that I need to configure a specific VLAN for this to work?

You could try cloning the MAC address of the ISP supplied router assuming your router supports cloning a MAC address.

 

[Lukapple]

I don't know what you've done to your router, nor am I familiar with that model.

I would power down the ONT (minimum 10 minutes). Reset the router, and power everything up, and try again.

An ONT is just an Ethernet WAN connection. Otherwise, it isn't an ONT.

If that doesn't work, you may need to contact the manufacturer of the USG Flex 500 for help in setting that up properly.

At this point, it just seems you've really messed up the router settings for no reason (and toggling settings isn't ideal for getting the router to do what the GUI is showing, sometimes).

I haven't made any changes to my router (Zyxel Flex 500) other than setting DHCP for the WAN connection. The screenshot with VLAN settings is from the ISP's router, to which I have limited access and cannot change these networking settings.

I will try powering down the ONT (or whatever it is) for a longer period and see if that helps.

You could try cloning the MAC address of the ISP supplied router assuming your router supports cloning a MAC address.

I already tried cloning the MAC address of the ISP-supplied router before they set it to bridge mode, but it didn't work.

It is a fact that the MAC address is registered on the ISP's side because the bridge mode didn't work until they registered the MAC address of my router on their end.
I would like to get rid of their router, and in my opinion, bridge mode should work the same as plugging the LAN directly into my router. Is there any trick I might be missing?

Thank you for your suggestion.

 

[Barmynon]

I haven't made any changes to my router (Zyxel Flex 500) other than setting DHCP for the WAN connection. The screenshot with VLAN settings is from the ISP's router, to which I have limited access and cannot change these networking settings.

I will try powering down the ONT (or whatever it is) for a longer period and see if that helps.


I already tried cloning the MAC address of the ISP-supplied router before they set it to bridge mode, but it didn't work.

It is a fact that the MAC address is registered on the ISP's side because the bridge mode didn't work until they registered the MAC address of my router on their end.
I would like to get rid of their router, and in my opinion, bridge mode should work the same as plugging the LAN directly into my router. Is there any trick I might be missing?

Thank you for your suggestion.

Have you tried connecting a laptop directly into your modem and seeing if it gets an IP?

 

[sfx2000]

I don't know what you've done to your router, nor am I familiar with that model.

I would power down the ONT (minimum 10 minutes). Reset the router, and power everything up, and try again.

An ONT is just an Ethernet WAN connection. Otherwise, it isn't an ONT.

It's quite possible that the ONT and the carrier provided CPE have internet on a VLAN - so would need more info on who the ISP is, and maybe this would be helpful.

This can be quite common, esp when it's a multiple service end-point - e.g. DialTone, Broadband, and TV for example... each would have their own VLAN ID...

 

[Lukapple]

Have you tried connecting a laptop directly into your modem and seeing if it gets an IP?

Yes, I have tried connecting a MacBook directly to the modem, but it only gets the IP 169.254.137.128, which is a link-local address (assigned when a device cannot obtain a valid IP address from a DHCP server).

It's quite possible that the ONT and the carrier provided CPE have internet on a VLAN - so would need more info on who the ISP is, and maybe this would be helpful.

This can be quite common, esp when it's a multiple service end-point - e.g. DialTone, Broadband, and TV for example... each would have their own VLAN ID...

It likely uses a VLAN, as the name of the LAN connection on their router is ETHWAN_VLAN1201_bridged. Additionally, there are two VLANs on their router that are probably used for phone services (but I don't use those, I only need the internet). The ISP is Telemach (a European ISP).