Problem with DHCP-Server

[openyoureyes76]

Hello,

unfortunately i have a problem with my router's DHCP server. It's not quite clear to me what the cause could be.

My Modem from my provider is a Zyxel Dx3101-B0. This is operated in single-user mode. Via LAN port, the Zyxel is connected to the WAN port of my Asus XT8 mesh (4 pcs.). The dial-up takes place accordingly via the Asus Main router. DHCP server runs on The Asus and is turned off on the Zyxel (unfortunately I am not 100% sure about that).

Every 2.5 minutes, an unknown wired device called "REALTEK SEMICONDUCTOR CORP" with seemingly infinite MAC addresses grabs a new IP. After a few hours, this means that no IP is available and some devices lose their Internet connection (apparently when the lease expires and no new IP can be assigned). The solution so far has always been to restart the router. In addition, I have reduced the lease duration in the DHCP server from 86400 to 3600. Since then, this unnecessarily assigned IP address has been released quickly enough and the problem at least does not lead to any connection problems. However, this does not solve the basic problem.

Does anyone here have an idea/approach where these problems might come from? On the PC I actually have a Realtek network adapter. However, ipconfig /all does not show me any of these mysterious connections.

Many Thanks in advance,

Harald

 

[bbunge]

Most likely you have a phone or other device that has randomise MAC address turned on.

 

[openyoureyes76]

After some further investigation i was able to identify two Reolink E1 surveillance cameras as the cause. They took a new IP-Adress every 2,5 min - always with a new MAC-Adress - no idea why. But turning them off completely solved the problem with the DHCP-Server.