Create a new range of extensions and random computers on my network have bound to them

I have just created a range of new extension that I am going to use soon, configured 3 desktop phones to get ready for deploying them and when I look in Reports / Asterisk Info / Peers I see three random computers on my network have seemingly attempted to bind to them but had status UNREACHABLE.

They disappeared after about half an hour but I am puzzled how this could have been.

Has anyone ever seem anything like this before?

I’m hoping that these extensions are not going to be affected when they are put into production.

I think you may have had too many things going on at once.
The PBX is not the issue here.