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skesinis Author

Level 1

23 points

macOS Sequoia LAN is totally unstable!

I've been having disconnection issues on SSH, VNC and SMB, since I installed macOS Sequoia, to the point that I couldn't keep an SSH connection up for over 5 minutes! In the beginning I thought it was just SSH, so I was trying different settings, different MTU which made it a bit more stable, I even downloaded a version of the SSH client that uses OpenSSL instead of LibreSSL that the macOS is using, but I was getting disconnections with corrupted packets of a huge random 32bit number invalid length. I was using a Realtek ethernet adapter, so I tried eleven different ones without success. I even dug out my old Apple Thunderbolt 2 to ethernet adapter, combined with a Thunderbolt 2 to 3 adapter, which showed a better behaviour on SSH. Using WireShark to capture the connections when they were failing didn't help, since the invalid packet length number wasn't anywhere to be found in the packet itself, as it was most likely on the SSH application layer, and thus encrypted.

However when I was trying to do a tar backup of 4TB SSD on my Synology NAS, the NAS kept disconnecting anytime from 10min to 120min randomly, completely destroying my backup and having to start it over. VNC connections on my Raspberry Pi weren't any different than the SSH.

I thought it was planned obsolescence for my 2019 Intel Core i9 MacBook Pro, but I've heard from others having M2 MacBooks having similar issues.

Is there any suggested solution?

MacBook Pro 16″

Posted on Oct 3, 2024 11:09 PM

Top-ranking reply

CaptainProtonMontreal

Level 1

14 points

Posted on Oct 19, 2024 9:08 AM

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.

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22 replies

Nov 5, 2024 4:34 PM in response to etresoft

Many of us prefer not to allow unrestricted inbound traffic to our machines. Personally, I set my system to block all incoming connections by default and only allow specific ones as needed. Since upgrading to macOS 15, however, I’ve been struggling to keep an SSH session open for more than 30 seconds before encountering “Bad packet length…” errors, followed by “Connection corrupted” and a terminated session.

Uninstalling Little Snitch and disabling the built-in firewall did resolve the issue for me temporarily, but I agree with @idjwert that suggesting users disable all firewalls and security software is generally poor advice. Solutions to connectivity issues shouldn’t involve turning off essential security measures—especially when users may not have a choice, like those on company-provided machines where disabling firewalls may be prohibited. I don’t allow users to disable the firewall on our company laptops for this reason.

I even attempted to revert to Sonoma, willing to sacrifice a few new features rather than risk exposure on the public internet, but this wasn’t feasible as key apps, including Mail and Photos, no longer functioned correctly due to database changes.

In the end, I temporarily disabled my firewall and uninstalled Little Snitch, accepting a calculated risk that’s mitigated by my control over network firewalls at home and work. However, I’m strictly avoiding public networks until this issue is resolved.

satcomer

Level 4

1,575 points

Nov 5, 2024 4:59 PM in response to CaptainProtonMontreal

It because you using two different clock syncing from your Mac to the NAS! You should use the same clocking on both devices! Clocking to NAS with two different clock sources means trouble over Time! So use a Federal sever instead off two different clock sources clock sources, this a Very old problem through the years even big networks I have been apart 35 years Engineer!

skesinis Author

Level 1

23 points

Nov 5, 2024 5:19 PM in response to satcomer

@satcomer

It was just a bug of the early Sequoia version 15.0 and 15.0.1

It’s fixed now on 15.1

The NAS was just a special case where I had a failing SSD for cache (2 of them in RAID1, 1 of them failing) and it was taking too long to write or read sometimes, thus it was disconnecting the NAS as an SMB device.

However, the SSH issue was happening everywhere I was trying to connect. It would disconnect within a few seconds to a few minutes with an error about an invalid packet length, followed by a random 32bit number, usually over 3billion bytes. That was happening on the application layer (thus encrypted), because WireShark wouldn’t find that number in any of the packets.

SerPom

Level 1

14 points

Oct 11, 2024 6:50 PM in response to skesinis

I started having stability issue and also after updating my M1 Imac Safari started freezing.

etresoft

Level 9

50,698 points

Oct 14, 2024 4:41 AM in response to idjwert

idjwert wrote:

Suggesting people run without any firewall at all, or without their security apps, is TERRIBLE advice. ABSOLUTELY TERRIBLE.

Please explain why.

tbirdvet

Level 6

14,339 points

Oct 20, 2024 4:28 PM in response to andr3w

I had both ethernet and WiFi on (ethernet first in service order). I had a web page that would not load most of the time so I turned off WiFi and now no issues just using the ethernet connection.

skesinis Author

Level 1

23 points

Nov 5, 2024 5:08 PM in response to skesinis

It was a bug of the early macOS v15.0 or 15.0.1

It’s fixed now on 15.1 (24B83).

macOS Sequoia LAN is totally unstable!