macOS Sequoia LAN is totally unstable!

It's not just SMB. My brand-new shared-over-afp NAS keeps disconnecting mid Time Machine backup. I've been seeing strange disconnections in ssh, and even acquiring an IP address by DHCP has been dodgy.

I didn't see ssh disconnection issues with macos 15 until upgrade to 15.0.1 :-(. Now, all LAN connections are unstable and unusable. I hoped Apple come up with another update to fix the issue.

There is clearly an SMB issue going on as I've had similar experiences with SMB related disconnects trying to run previously working Time Machine backups to my Synology, 15.01 is clearly at fault. I had SMB issues (disconnects/Finder crashes) on Mac OS 14, but this only occurred when I had Time Machine running a backup while also transferring files to my Synology.

[Edited by Moderator]

connect to the NFS, SMB, and xRDP services on my Ubuntu 24.04-based home server. They all worked stably with Sonoma until I upgraded to Sequoia, no matter 15.0, 15.0.1 official or 15.1. I think this problem is not protocol-specific but is rooted at something wrong down below the Transport Layer.

etresoft wrote:

Here are some things to try:

1) Make sure System Settings > WiFi > Private WiFi Address is set to "fixed"

2) Make sure you aren't running any kind of firewall or network filter.

3) Make sure you aren't running any kind of 3rd party "security" or "privacy" app

4) Go through #2 and #3 again. Yes. "Little Snitch" belongs in this category too.

and as of today

5) Update to Sequoia 15.0.1. Supposedly it works better with some of those 3rd party security apps.

Edit: totally spaced this out

2a) Make sure you aren't running any kind of VPN. Some of them work. Some of them don't.

Suggest that you do NOT update to Sequoia 15.0.1 it has spread these problems to droves of users who weren't having them before. 15.0.1 will not keep stable network connections with the firewall enabled. It may have something to do with running Little Snitch at the same time - if you have Little Snitch properly configured, you don't need the Apple firewall. Suggesting people run without any firewall at all, or without their security apps, is TERRIBLE advice. ABSOLUTELY TERRIBLE.

Hi,

I faced the issue with the lan access from the apps that aren't of Apple, for example Chrome, Termius (ssh, sftp client) and so on.

In particular I get problems when I try to access in HTTPS or SSH to a local resources like Raspberry, internet router or switch.

To temporary resolv the issue (when it appear), I have to deactivate and reactivate one app from the lan access from system setting -> privacy and security -> Local Network (I hope those are the right names of the menu, I'm not have the engligh language on my mac).

With Safari or terminal I can access to local resources in HTTPS or SSH without any problem.

I think the problems are due to the Network Access feature that it doesn't works right.

[Edited by Moderator]

Here are some things to try:

1) Make sure System Settings > WiFi > Private WiFi Address is set to "fixed"

2) Make sure you aren't running any kind of firewall or network filter.

3) Make sure you aren't running any kind of 3rd party "security" or "privacy" app

4) Go through #2 and #3 again. Yes. "Little Snitch" belongs in this category too.

and as of today

5) Update to Sequoia 15.0.1. Supposedly it works better with some of those 3rd party security apps.

Edit: totally spaced this out

2a) Make sure you aren't running any kind of VPN. Some of them work. Some of them don't.

D3vildog76 wrote:

@etresoft while help, is helpful you're prescribing level 1 support concepts to a (original issue) poster that is level 3 all day long.

I have no idea what you are talking about with level 1s and level 3s.

Many people are having general networking problems with Sequoia. In this situation, anyone having such problems must confirm that they have gone through all of those steps. Otherwise, any attempts to help or any further attempts to diagnose the problem are a total waste of time for everyone.

These networking problems affect all protocols. They absolutely must be eliminated before discussing a notoriously complicated protocol like SMB.

As far as SMB goes, I have no idea what people are doing when they report problems with Sonoma or Sequoia. In every case, they always claims it was perfect before the upgrade. But I've used Mac networking with SMB and I know that is has always been far, far from perfect.

The OP does not appear to be using WiFi, but rather wired Ethernet. Does the WiFi setting mentioned at (1) have some effect on Ethernet networking too? I didn't see a "Private WiFi Address" option when I looked just now, but perhaps that's because I have WiFi on but not connected (on for location services, not connected because of Ethernet). Doesn't appear to be a "Private" option for Network > Ethernet either.

Don't know why my few replies are disappeared. I have the exact issue with my Macbook Pro 16(2019). What I have to do is " make inactive" all the network connections (WiFi, wired Ethernet) and "Make active" again.

exact the same issue here

Many thanks. so far, your suggestion is working on my macbook.

Update on my above situation. As suggested by many in this thread, uninstalling Little Snitch restored networking and allowed me to complete Time Machine backups to NAS. Reinstalled Little Snitch as a test: all the issues returned. I haven't tried keeping Little Snitch + disabling MacOS firewall yet... I'll wait for 15.1 before trying that.

From what I gather this is happening at a very low-level of the network stack (probably the transport layer), affecting wired and WiFi networking.