Mac Devices Register DNS with Generic Hostnames on WiFi but Correct Names on Wired Connection

[__AMM]

Hi Jamf Community,

We're experiencing an interesting DNS registration issue with our Mac fleet that I'm hoping someone might have encountered before.

Issue Description

When our Mac devices connect to our corporate WiFi network, they register in DNS (Infoblox) with generic names like mac.domain or macbook.domain instead of their proper hostnames (e.g., mbp-dav.domain). However, when these same devices connect via Ethernet cable, they register correctly with their actual hostnames.

Environment Details

• DNS/DHCP: Infoblox
• Mac devices: Various models running macOS
• All Mac devices have proper hostnames configured

What I've Verified

I've confirmed the hostname settings are correctly configured on the affected devices:

scutil --get HostName

mbp-dav.domain

scutil --get LocalHostName  

mbp-dav.domain

scutil --get ComputerName

mbp-dav.domain

System preferences show the hostname is correctly set in the Mac's configuration, and I've checked the DHCP packets which don't seem to include any hostname options that might cause this behavior.

Questions

1. Has anyone else encountered this issue where Macs register differently on WiFi vs. wired connections?
2. Are there specific settings in Jamf or on the Mac that could address this inconsistency?
3. Could this be related to how the Mac's mDNS/Bonjour services interact with Infoblox on different network types?

Any insights or suggestions would be greatly appreciated. Thanks in advance for your help!

[sdagley]

@__AMM Have you checked with Infoblox support? I think this is a known issue.

[Valcovish]

It sounds like your Macs are using a different method to register their hostname in DNS over Wi-Fi versus wired connections. Here are some potential causes and troubleshooting steps:

1.DHCP Hostname Registration: Some Wi-Fi networks don’t properly pass the client hostname to the DHCP server, leading to default generic names. Check if your Wi-Fi VLAN is configured to allow hostname registration.

2.mDNS vs. DNS Registration: macOS uses both mDNS (Bonjour) and traditional DNS. When on Wi-Fi, the system may prioritize mDNS, leading to unexpected hostname behavior. Ensure that SetHostName, SetComputerName, and SetLocalHostName are consistent across network interfaces.

3.Infoblox DHCP Settings: Since your Macs register correctly over Ethernet, the issue could be Infoblox treating Wi-Fi connections differently. Verify if Infoblox has separate handling for hostnames based on interface type and check if Dynamic DNS updates are enabled for wireless connections.

4.Jamf Configuration Profiles: If Jamf is enforcing a naming convention, make sure it applies to all interfaces, including Wi-Fi.

5. Try Manually Registering Hostname: Run:

sudo scutil --set HostName mbp-xyz.domain.com
sudo scutil --set LocalHostName mbp-xyz
sudo scutil --set ComputerName mbp-xyz
dscacheutil -flushcache && sudo killall -HUP mDNSResponder

Then reconnect to Wi-Fi and see if it resolves the issue.

If the problem persists, checking Infoblox logs and DHCP lease details might provide more insights.

[__AMM]

we opened a ticket with Infoblox, but they have indicated that the issue is not on their end.

I’ve also verified the local settings on the affected Macs, including the hostname configuration in all three places (HostName, LocalHostName, and ComputerName), and the issue persists.

Any additional thoughts or suggestions would be appreciated.