I need some help. My Mac Studio renames itself everytime I reboot it.

[svenmany]

Hi,

From our EPSON printer, network status sheet:

<TCP/IP IPv4>
IPv4: Enable
Obtain IP Address: Auto(DHCP)
IP Address: 192.168.x.x
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.x.x
APIPA: Enable
Acquisition way of DNS ADDR: Auto
Primary DNS Address: router ip
Secondary DNS Address: none

<Dynamic DNS>
Dynamic DNS: Enable
Host Name: EPSON.speedport.ip
Obtain Host Name: Auto

<Bonjour>
Bonjour: Enable
Bonjour Name: EPSON.local
Bonjour Service Name: EPSON printer name


Everything works fine. We just typed in the password for our WLAN/WiFi and it just works.

It does feel off-topic to address this, but there's a chance the OP has moved on from this issue.

You can see that nowhere is ".speedport.ip" shown next to ".local". Those are two entirely different namespaces that the local name "EPSON" is a member of.

The only thing relevant to this thread is the Bonjour section. The other section refers to classical DNS, with a DNS server being authoritative for the names within the speedport.ip domain. With Bonjour/mDNS, there is not authoritative server; the management of names is a collaborative effort.

Now - really, really off-topic

The "Dynamic" in the section's name probably refers to RFC 2136 (or some popular extension of it). In that case the Epson printer might be attempting to tell the authoritative server to update its records. Whether the DNS server on your router actually does that depends on whether your router respects that protocol. I would need to install a plugin to have my router support that. You can read more about that here

https://en.wikipedia.org/wiki/Dynamic_DNS

I also found

https://download.epson-europe.com/pub/download/3747/epson374793eu.pdf

and the relevant quote:

10. Select Enable for Register Network Interface Address to DNS Server if you want to register
the host name and domain name to the DNS server through the DHCP server that supports
Dynamic DNS.

If you want to register the host name and the domain name directly to the DNS server, select
Enable for Register Network Interface Address Directly to DNS Serve

This is a confusing description because the first paragraph is not effected by the behavior of the printer. The DHCP server is the one that is configured to update the DNS server (as is the way it works on my router). The second paragraph is the one that's actually about dynamic DNS efforts that the printer participates in.

 

[boppin]

You can see that nowhere is ".speedport.ip" shown next to ".local". Those are two entirely different namespaces that the local name "EPSON" is a member of.

Yes, I know.

The first is for DNS / DHCP, while the .local is for the Bonjour service. Will only appear, when a device can support it like "old" Windows machines by installing Bonjour for Windows. Some people seem to be confused by the different suffixes.

And Bonjour is a so-called zeroconf service which announces itself independent to the network. Use Discovery app to check this.

:EDIT:

Tildesoft

www.tildesoft.com

Although it's obsolete it still works!

But DNS and DHCP usually need a server, except when configured manually which is no longer the case today. Most routers will do this for you.

:edit 2:

The DNS search domain by famous Fritz!Box by AVM is always ".fritz.box"

And I found a good example for what I meant earlier in this thread. When the user did not used the space then the message would be

"Other users can access shared folders on this computer, and administrators
all volumes, at smb://minimumminival

Because it's only 15 characters long with fits the specifications.

 

[transmaster]

Talk about feeling like an idiot. Finally called EERO Support, and they fixed me up. The Mac Studio has paired WiFi and hard-wired Ethernet. Once the tech had me check the status of the Mac on the EERO, in the Mac's profile, you would see the WiFi connection. I turned off the WiFi connection on the Mac, and that fixed it. Apparently, with the update to macOS 26, something changed that caused the problem.
The Mac is named W7ITC. Now, everything WiFi is going through the EERO router.

 

[BigBlur]

Talk about feeling like an idiot. Finally called EERO Support, and they fixed me up. The Mac Studio has paired WiFi and hard-wired Ethernet. Once the tech had me check the status of the Mac on the EERO, in the Mac's profile, you would see the WiFi connection. I turned off the WiFi connection on the Mac, and that fixed it. Apparently, with the update to macOS 26, something changed that caused the problem.
The Mac is named W7ITC. Now, everything WiFi is going through the EERO router.

View attachment 2631306

Isn't that what the first reply to this thread suggested to do?

Try using either Ethernet or WiFi, but not both enabled at the same time.

 

[transmaster]

I spoke too soon; the renaming happened just took longer this time.

 

[boppin]

The Mac Studio has paired WiFi and hard-wired Ethernet.

Are you connected via both WiFi and Ethernet at the same time? Really? Why are you doing this?

If you need to use both, please use different IP ranges. Like my cousin and I connected our Macs in 2006.

 

[bogdanw]

As it wasn't mentioned so far, disable IPV6 from Terminal
- disable IPv6 for Wi-Fi

networksetup -setv6off Wi-Fi

- disable IPv6 for Ethernet

networksetup -setv6off Ethernet

 

[Weaselboy]

I spoke too soon; the renaming happened just took longer this time.

This does not fix your problem, but just as a data point, I am on Tahoe 26.5 and use ethernet and wifi at the same time and don't have this problem. On a MBP in clamshell mode.

 

[jerryjohnson]

Classic Apple support move:
“It's your router.”
Meanwhile the Mac is arguing with itself on a network with literally one computer connected.
Definitely sounds like a macOS hostname/Bonjour bug, especially since it started right after updating to 26.

 

[svenmany]

Talk about feeling like an idiot. Finally called EERO Support, and they fixed me up. The Mac Studio has paired WiFi and hard-wired Ethernet. Once the tech had me check the status of the Mac on the EERO, in the Mac's profile, you would see the WiFi connection. I turned off the WiFi connection on the Mac, and that fixed it. Apparently, with the update to macOS 26, something changed that caused the problem.
The Mac is named W7ITC. Now, everything WiFi is going through the EERO router.

View attachment 2631306

I now the problem resurfaced after this post. I'm most intrigued by the phrase "paired WiFi and hard-wired Ethernet". Are you suggesting that the interfaces were bridged or some other advanced configuration change was made? What software are you running which might have don't some networking changes?

Not that I trust Claude over 60% on an initial query, but I did read just now:

SDR / Radio software — apps that interface with software-defined radios sometimes set up virtual network interfaces or bridges, especially if they're routing audio/data streams over a local network to companion apps.

Also, even if you've eliminated one interface, the Eero could still have a cache of the old stuff. If you eliminate one interface permanently, reboot your routers and computer after that before you make any conclusions about the success or failure of that remediation.

 

[boppin]

It's not a good idea to be connected with Ethernet and WiFi the same together. If you really need Ethernet, use another IP range. Like 192.168.2.x, while WiFi should get the IP address by the router via DHCP.

And it's also not a good idea to disable IPv6.

 

[Weaselboy]

It's not a good idea to be connected with Ethernet and WiFi the same together.

It shouldn't cause any problems. I have been doing this for years and have no issues.

If you run off ethernet and have wifi off, you will lose some features like AirDrop and Continuity. I think it also disables auto unlock with Apple Watch if that matter to you.

 

[boppin]

It shouldn't cause any problems. I have been doing this for years and have no issues.

When connected both ports to a router then yes. Did caused also problems back then by the iMac of a former colleague.

So see Mac "sees" itself and renamed itself.

In 2006 my cousin and I have had a special setup. How to use file sharing between two Macs and using Internet via Airport? Well, the solution was dead simple. First, use two separate IP ranges, as said before, second, use a crossover cable and third, put Ethernet as the first connection in system preferences.

 

[transmaster]

It turns out the WiFi connection on the Mac Studio has to be enabled because that is how the Apple Watch connects to the Mac. This is how the Watch opens the Mac Studio. I did a total reload of macOS 26.5; it took hours. It made no difference.

 

[boppin]

It turns out the WiFi connection on the Mac Studio has to be enabled because that is how the Apple Watch connects to the Mac.

And you didn't followed the steps I already mentioned?

 

[svenmany]

It turns out the WiFi connection on the Mac Studio has to be enabled because that is how the Apple Watch connects to the Mac. This is how the Watch opens the Mac Studio. I did a total reload of macOS 26.5; it took hours. It made no difference.

And you restarted your routers after that? If the problem is caching of names on the routers, they are completely unaware of what you've done on your computer, the problem would still be there with your fresh computere.

 

[svenmany]

When connected both ports to a router then yes. Did caused also problems back then by the iMac of a former colleague.

So see Mac "sees" itself and renamed itself.

Not a problem. The mDNS spec provides provisions for this situation, which I documented in an earlier response. There is no mDNS naming conflict for a single computer to share the same name with all of its interfaces. I've been doing this for decades.

Problems could arise if you play with VLANs, bridges, or other analogous things.

 

[bapegg]

Not a problem. The mDNS spec provides provisions for this situation, which I documented in an earlier response. There is no mDNS naming conflict for a single computer to share the same name with all of its interfaces. I've been doing this for decades.

Problems could arise if you play with VLANs, bridges, or other analogous things.

I have ran both ethernet and WIFI on my Mac Mini's for years without any issues. I don't use VLANs or bridge any connections for virtual machines, etc.

As mentioned, Airplay and other Apple services won't work without WIFI.

 

[svenmany]

I have ran both ethernet and WIFI on my Mac Mini's for years without any issues. I don't use VLANs or bridge any connections for virtual machines, etc.

As mentioned, Airplay and other Apple services won't work without WIFI.

Exactly. That's why I always run both.

I have a managed switch which I've set up with 4 VLANs. I've also played with assigning VLAN numbers to various multi-homed devices on my network. When I've made a mistake doing that, I gotten the renaming behavior we're discussing. I don't think I was ever able to reason through why it was happening. I should have tried harder to understand, but when all hell is breaking loose because of a network change, it's hard to stay calm. I always do these kinds of things on the weekends when my kids happen to be visiting. So, I always have their networking concerns and my wife's to consider. "Dad, did we loose internet?!?"

The mDNS spec at https://www.rfc-editor.org/info/rfc6762/ talks about the issues related to multi-homed hosts and each interface checking the availability of the same name. It discusses the use of timeouts to handle this exact issue. Here's the relevant section:

There is one other special precaution that multihomed hosts need to take. It’s common with today’s laptop computers to have an Ethernet connection and an 802.11 [IEEE.802.11] wireless connection active at the same time. What the software on the laptop computer can’t easily tell is whether the wireless connection is in fact bridged onto the same network segment as its Ethernet connection. If the two networks are bridged together, then packets the host sends on one interface will arrive on the other interface a few milliseconds later, and care must be taken to ensure that this bridging does not cause problems:

When the host announces its host name (i.e., its address records) on its wireless interface, those announcement records are sent with the cache-flush bit set, so when they arrive on the Ethernet segment, they will cause all the peers on the Ethernet to flush the host’s Ethernet address records from their caches. The Multicast DNS protocol has a safeguard to protect against this situation: when records are received with the cache-flush bit set, other records are not deleted from peer caches immediately, but are marked for deletion in one second. When the host sees its own wireless address records arrive on its Ethernet interface, with the cache-flush bit set, this one-second grace period gives the host time to respond and re- announce its Ethernet address records, to reinstate those records in peer caches before they are deleted.

As described, this solves one problem, but creates another, because when those Ethernet announcement records arrive back on the wireless interface, the host would again respond defensively to reinstate its wireless records, and this process would continue forever, continuously flooding the network with traffic. The Multicast DNS protocol has a second safeguard, to solve this problem: the cache- flush bit does not apply to records received very recently, within the last second. This means that when the host sees its own Ethernet address records arrive on its wireless interface, with the cache- flush bit set, it knows there’s no need to re-announce its wireless address records again because it already sent them less than a second ago, and this makes them immune from deletion from peer caches. (See Section 10.2.)

 

[smithrh]

Two items:

While I have not done extensive testing, AirPlay and similar services work fine in my use cases with WiFi off completely (e.g., both sides have no WiFi). I will say the only thing that I have run into that requires WiFi is AirDrop. Again, just my incomplete experiences so testing on your needed services is a good idea.

Also, there's been some sort of change in 26.5, or at least that's when I noticed it: when the service order is changed (WiFi to Ethernet, Ethernet to WiFi) the established connections remain up. In the past they've been dropped.

That is to say, if I had remote screen sharing up and running on Ethernet, and file sharing also up on Ethernet, if the Ethernet is disconnected WiFi now takes over nicely with only minor hiccups. In the past usually the connections would be... disconnected.

Typically I have been manually disabling WiFi on any Mac that also had Ethernet, which is how I've found that many services don't require WiFi (save AirDrop). But if after more testing I can see that having both Ethernet and WiFi "on" at the same time (not load balancing) with the service order being honored, I may try leaving WiFi on permanently.

 

[svenmany]

Two items:

While I have not done extensive testing, AirPlay and similar services work fine in my use cases with WiFi off completely (e.g., both sides have no WiFi). I will say the only thing that I have run into that requires WiFi is AirDrop. Again, just my incomplete experiences so testing on your needed services is a good idea.

Also, there's been some sort of change in 26.5, or at least that's when I noticed it: when the service order is changed (WiFi to Ethernet, Ethernet to WiFi) the established connections remain up. In the past they've been dropped.

That is to say, if I had remote screen sharing up and running on Ethernet, and file sharing also up on Ethernet, if the Ethernet is disconnected WiFi now takes over nicely with only minor hiccups. In the past usually the connections would be... disconnected.

Typically I have been manually disabling WiFi on any Mac that also had Ethernet, which is how I've found that many services don't require WiFi (save AirDrop). But if after more testing I can see that having both Ethernet and WiFi "on" at the same time (not load balancing) with the service order being honored, I may try leaving WiFi on permanently.

I've started doing some testing with Wi-Fi turned off.

• iPhone mirroring fails immediately with the message "Turn on Mac Wi-Fi to connect."
• I can no longer access my iPad as an extended display or to control it as a normal iPad using my computer's mouse and keyboard.
• Continuity camera (where I use my iPhone on computer-based Zoom calls) doesn't work.

Have you been able to get these kinds of things working with WiFi off? I'd like to do more testing. I do see that Airplay does work. What "similar services" are you referring to that work fine?

 

[Honza1]

I did not check all replies - way too many, so may be someone suggested this… Check wifi and ethernet setting for private wifi address settings (and whatever ethernet names it). When on, after every reboot your computer gets new random MAC address for your home network and your router considers your device new device (different MAC) asking for the same name. It still holds the name for the old MAC address device, so it gives you different one.
This is preventing wifi providers from tracking your computer without you allowing them to store cookies. With this not enabled, you do not even have to connect and wifi network can fingerprint you by the MAC address…
This has been around for some time now, but may be was enabled by update. It is driving our IT department nuts ;-)

 

[Bigwaff]

This has been around for some time now, but may be was enabled by update. It is driving our IT department nuts ;-)

Both macOS and Windows 10/11 have supported this for quite some time. Your IT department must be a bunch of doofuses.

 

[OldAppleIIUser]

Your EERO router can not "change" the host name of your computer. My DSL router lets you name devices by MAC address, but also can not change the host name of an external device.

My guess is Bigwaff is correct in that you need to use either wired or wireless. Since you are feeding both from the EERO, the computer sees a conflict from the other port.

Although to be honest, on show site I have had my laptop connected to wireless and wired and not seen this, also using an EERO router.

Funny, the host name on my home EERO router does not show the correct one for my Mac Pro; lol, I disconnected and connected again and now it is right. ha ha.

Weird.

I also have both active on an M4 studio, but running on Sequoia and have not had this concern take place. I put iOS on my iPhone and hated it, so I will not put it on my M2 mini nor my M4 Studio. I do not know why Apple has decided to put mobile OS on desktops except that it cost them less in the long run.

 

[transmaster]

I cannot find the IP reservation setting, I have no advanced settings, or network settings.