macOS frequently adding a number to the name of my computer

James Sepe wrote:

The Mac Studio does have both wired and wireless networks. Wired for speed and wireless for Airdrop which I use constantly.

Are you sure about that? Have you compared the speed with one being disconnected? You might be surprised.

I am using eero as my network. I thought maybe it was rotating MAC addresses but this morning I woke to Mac Studio (7) where last night it was just Mac Studio. I checked the MAC address and they had not changed.

I see a lot folks having this issue but no really solution. Any thoughts?

Your network is confused by the multiple interfaces. Easy solution is to disconnect the wired interface. Maybe there is some fix you can do in the Eero network. Maybe not.

I run both interfaces at the same time and do not have any problems.

However, I set up my router to provide reserved IP addresses to each MAC address.

I think I have the DHCP reservation set for 24 hours or something longer than the standard default. I'm not at home to check.

What has been described in the past is that the DHCP reservation for the Mac is still active when the Mac wakes and starts talking to the DHCP server for IP address. Somehow, the communication is garbled and the Mac thinks there is already another computer using that IP address, using the same name, so it changes the name. As etresoft noted, I believe it is tied to having both interfaces active.

With the reserved IP addresses I have never seen that problem happen on my network.

James Sepe wrote:

I will try turning off the WiFi for a while and see if the (number) gets appended. After that I will also try setting the Mac Studio's network interfaces to manual and specifying the IPs bypassing DHCP.

Sorry. Apparently I wasn't blunt enough. Pull. The. Plug. Use WiFi instead.

James Sepe wrote:

I did test my speeds on Ethernet vs. WiFi and they were 94.3 Mbps (Ethernet) vs 77.8 Mbps (WiFi).

Are you sure about those numbers? You are writing "Mbps" - Mega-Bits per second. Or did you mean to write MBps - Mega-Bytes per second?

I ask because those values are either extraordinarily bad or extraordinarily good. Modern Wifi, on both the client and router, can saturate anything less than a fibre internet connection. For example, I have (in theory) 1.5/1.0 Gbps fibre. My older Linux machine with 10gig ethernet can get 75 MBps. My 2020 M1 MBP can get 72 MBps over WiFi.

Sorry, I just checked an address near where a friend used to live in Lomita. ATT really does offer only 75 Mbps. And they call that fibre?

Anyway, that settles the question. Don't waste your time with the ethernet. Just use WiFi. Your WiFi is several times faster than your internet. I guess your Eero network gets confused by the multiple interfaces and/or the ethernet. So just use the WiFi.