USG FLEX 500 - Internet with fixed IP does not work.

D2IT

Hello, we are facing a problem with the USG FLEX 500, where we have an internet link with a fixed IP that does not work on this firewall. It is not possible to access the internet, not even to ping the internet link gateway. However, when testing this same link with the same fixed IP settings on any other device, the internet works perfectly.

We have already reset the USG FLEX 500, updated the firmware, downgraded the firmware, and tested with another network cable. Both the LAN and the firewall itself are without internet, since it is not possible to ping through the firewall CLI. We also tested configuring the MAC of the old firewall (USG60) on the WAN1 interface of the USG FLEX 500, but the problem persists.

We contacted the operator, and they informed us that there is no device or MAC blocking. They stated that, by configuring the IP, mask, and gateway correctly, the internet should work, which in fact occurs on any other device.

We tested using another firewall port, but the problem persists. We also performed a test using another internet link with DHCP, and this one works on the firewall.

PeterUK

With a fixed IP on the device thats working change its MAC and see what happens

D2IT

It has already been done, both with the original Zyxel USG 500 MAC and with the cloned USG 60 MAC.

PeterUK

So does a PC connected to the wan with fixed IP work? copy its MAC to Flex

D2IT

We have also carried out the test using a notebook, connecting the network cable from the operator's link and configuring the fixed IP in the same way as in the USG 500. On the notebook, the internet also works.

PeterUK

So copy notebook MAC to the Flex WAN and see if that works

D2IT

This has also been tried, but it didn't work. The internet provider doesn't impose any restrictions on the MAC; any device correctly configured with the IP, mask and gateway should be able to access the internet. Only on the USG 500 this internet doesn't work.

PeterUK

I don't get why its not working

Guess the only thing to do is a packet capture on the WAN as you ping 1.1.1.1 on the Flex and see if it ARP to the gateway

Zyxel_Melen

Hi @D2IT,

1. May I know if any other devices have the same ISP IP connected to the ISP link at the same time?
2. Could you help to collect the diagnostic info for me to check? I will DM you for the file.