200H - No WAN from ISP modem

MarcoPale

Hi,

I am installing the firewall in question to a client of mine, replacing an old NSG50. Unfortunately, by connecting from the modem to the p1 (GE1) port of the firewall,

20250611_151846.jpg

either in dhcp or static, I cannot get ip from the modem.

The old NSG50 was configured in static mode and reconnecting it I have no problem. The P1 port led on the new one, even when connected to the modem, does not light up.

Zyxel_Judy

Hi @MarcoPale ,

To confirm whether this is a hardware issue with the USG FLEX 200H, please try the following:

Hardware Testing:

• Replace the Ethernet cable between the USG FLEX 200H and modem with a known working cable
• Connect port 1 of the USG FLEX 200H to other devices (such as a switch or laptop)

Observe whether port 1 light up. If port 1 does not light up, this indicates a hardware failure. Please initiate the RMA process to request a replacement unit.

If there is no hardware issue with the USG FLEX 200H, but the WAN port still doesn't obtain an IP address when connected to the modem, please contact your ISP to check if they have configured MAC address binding (IP-to-MAC reservation), the setting ensure only authorized devices can obtain specific IP addresses. If this is the case, provide your ISP with the new device's MAC address and request they update their system accordingly.

MarcoPale

Hi,

port P1, as well as P2 are 100% working (tried with other devices).

By connecting a notebook to the modem port and manually setting the parameters (as attached 1st post) I have the network without problems so I don't think it is MAC binding.

PeterUK

maybe the MAC used on the NSG50 was the notebook MAC when it was cloned?

You can get it setup by double NAT then maybe try one of the 1Gb ports as WAN or set link speed on 2.5Gb to 1Gb or put a switch between the links

MarcoPale

• . Nope

• . Yes, I had thought of trying that way because my guess is that there is an “incompatibility” on the ISP modem/router side.