ssh connection corrupted error?

[vaalbara]

I hope this is the right place to ask.

I'm using an Anker PowerExpand 8-in-1 hub for a wired connection on a AS MBP running Ventura. From time to time I'm getting disconnected from ssh with the following error message:

Bad packet length 1551924576.
ssh_dispatch_run_fatal: Connection to XX.XX.XX.XX port 22: Connection corrupted

How should one start debugging to find the culprit? This seems to be occurring for both local IP's and remote servers. I got ServerAliveInterval set to 120 on the local MBP.

 

[Slartibart]

Any Proxy? What MTU size are you using?

 

[vaalbara]

Hmm. Thanks for asking. I'm using a VPN most of the day with Tunnel Blick but only traffic to specific servers are being routed over it. I don't know if this counts as a proxy of some sort? I think I should test ssh when that connection is inactive.

MTU should be the default value (1500).

 

[SantaCB]

I was facing the same issue recently and was a bit lost on how to troubleshoot it as well.

I did however find a post suggesting the ServerAliveInterval, but also the TCPKeepAlive setting.

I ended up adding the following to my config file and have not been disconnected since

ServerAliveInterval 60
TCPKeepAlive yes

shoutout to the original poster link here

 

[naa]

very annoying. I recently started using macOS and seeing this daily on Ventura. Never experienced this error while using Windows and Linux openssh client, on the same wifi network to the same ssh server

 

[vaalbara]

very annoying. I recently started using macOS and seeing this daily on Ventura. Never experienced this error while using Windows and Linux openssh client, on the same wifi network to the same ssh server

Sad to hear.

I actually haven't yet had the chance to find a fix. The ssh_config lines did not help.

All I know is that this is not due to my network setup: when I connect an old x86 MBP side by side (using an Apple TB3 ethernet dongle) ssh drop only occurs on the new MBP.

I'll try to find a different adapter that uses a Realtek 8156B chip instead of the Asix AX88179A that Anker uses. I'm not that hopeful since both will be using the generic USB CDC-NCM driver that comes with the OS but we'll see.

 

[Slartibart]

Try wether it helps to configure your system not to use Ed25519 for SSH for that particular system(s). Assuming the host is vaalbara.org add e.g.:
Host vaalbara.org HostKeyAlgorithms ssh-rsa
to ssh config. you can explicitly define which signature algorithm is to be used for server authorisation via HostKeyAlgorithms.
Other than that I would check with a slightly smaller MTU size e.g. 1453 on your router/Mac.