Assistance Needed for Network Configuration: Removing ISP Router

OldFox Posts: 16  Freshman Member
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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.


Thank you!

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