I find 2 external ip:s in my ARP table, there should only be one.

[enjoytheview]

I have to flush the ARP table to get rid of the other external IP, but within an hour or so it's back. I blocked the second external IP in the firewall, both in WAN and LAN.. but it still shows up in ARP.

I contacted my ISP via their support chat and they confirmed that there were 2 different external IPs in use. 2 devices with different MAC addresses. But I only have one device connected, my OPNsense. The support chat person thought this was a bit odd. Later on in the chat, he told me that everything was fine and that I only had one IP assigned to my device. After he wrote that, I copied some of his former answers into the chat where he had confirmed that there were 2 different IPs and his response was that he had misunderstood the situation. This is weird. Why did he change his mind suddenly? Maybe I'm being surveilled, I thought.

However..

Can I create a static ARP table? I can't find a guide on how to do this.

And, if I turn off DHCP on my WAN and configure IP + gateway.. can this stop the not welcome IP from connecting to my ARP table?

[enjoytheview]

Now I see 3 external ip:s in my ARP table.. My ISP only allows every custmer 2 external ip:s..

[cookiemonster]

It could be the IP of the gateway for your WAN, and that would be normal and actually necessary to be in the table.