MacOS Sonoma 14.0 breaks ethernet (Cisco AnyConnect socket filter) fix

MacOS Sonoma 14.0 breaks the Cisco AnyConnect DNS Proxy socket filter

The MacOS Sonoma upgrade that is offered from the MacOS System Settings -> General -> Software Update will download and install version 14.0.  This was confirmed recently with a fresh upgrade attempt this way - the installer was not downloaded before.  The App Store will install the most recent version (14.3 at the moment), but the upgrade option from the OS gives you 14.0 - and promptly offers more updates.

MacOS 14.0 will break Cisco AnyConnects DNS Proxy socket filter for the ethernet interface.  The fix is to either get the MacOS up-to-date via Wifi, or disable the socket filter, do updates, and re-enable.  With the majority of UW Mac users having laptops (and many iMacs have Wifi turned on out of the box), we've not seen too many macs only on ethernet.

Open Applications -> Admin By Request and start an admin session first:

Admin by request logo

Goto Apple Menu -> System Settings -> Network:

network settings window

Click filters, click DNS proxy -> Disable from the drop-down:

disable filter

The filter will then show as disabled:

filter disabled

The ethernet will now be functional.  Update the MacOS to the latest version, and after the restart, go back in and re-enable the DNS Proxy:

enable filter picture

The socket filter will then show as active:

filter enabled picture

Ethernet should be working now with the filter turned on.

End the Admin By Request session.

If this did not fix the issue, you may also try running the follow completely 



KeywordsMacOS, Sonoma, 14.0, Cisco, VPN, AnyConnect, broken, ethernet, socket, filters   Doc ID135031
OwnerDavid H.GroupUW-La Crosse
Created2024-01-25 11:06:04Updated2024-07-19 15:48:26
SitesUW-La Crosse
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