Corrupted MAC on input

[bob prohaska]

I'm seeing errors like this on my RasPiOS Pi4 ssh client host:

Connection closed by remote host
Corrupted MAC on input.
ssh_dispatch_run_fatal: Connection to 50.1.20.29 port 22:
message authentication code incorrect

They show up after a successful ssh login, usually shortly after,
sometimes never. The connection can be re-started, but the error
persists even after rebooting the remote host.

It happens with some hosts and not others, I'm trying to figure
out if it's my RasPiOS workstation or the clients (FreeBSD)
reporting the error. The IP number shown is of the remote host,
but which MAC is being complained about and by whom I can't tell.

If anybody's seen this or has a clue please post!

Thanks for reading,

bob prohaska

[Richard Kettlewell]

bob prohaska <b...@www.zefox.net> writes:
> I'm seeing errors like this on my RasPiOS Pi4 ssh client host:
>
> Connection closed by remote host
> Corrupted MAC on input.
> ssh_dispatch_run_fatal: Connection to 50.1.20.29 port 22:
> message authentication code incorrect

A message received from the server was corrupted. Off the top of my
head, possible causes include:

- some fault in the network between the two endpoints
- faulty network device on one endpoint or the other
- faulty RAM on one endpoint or the other
- software bug on end endpoint or the other (unlikely, everyone else
would be impacted)

> They show up after a successful ssh login, usually shortly after,
> sometimes never. The connection can be re-started, but the error
> persists even after rebooting the remote host.
>
> It happens with some hosts and not others, I'm trying to figure
> out if it's my RasPiOS workstation or the clients (FreeBSD)
> reporting the error. The IP number shown is of the remote host,
> but which MAC is being complained about and by whom I can't tell.

In this context ‘MAC’ means
https://en.wikipedia.org/wiki/Message_authentication_code, not a network
card’s MAC address.

--
https://www.greenend.org.uk/rjk/

[bob prohaska]

Richard Kettlewell <inv...@invalid.invalid> wrote:
> bob prohaska <b...@www.zefox.net> writes:
>> I'm seeing errors like this on my RasPiOS Pi4 ssh client host:
>>
>> Connection closed by remote host
>> Corrupted MAC on input.
>> ssh_dispatch_run_fatal: Connection to 50.1.20.29 port 22:
>> message authentication code incorrect
>
> A message received from the server was corrupted. Off the top of my
> head, possible causes include:
>
> - some fault in the network between the two endpoints
> - faulty network device on one endpoint or the other
> - faulty RAM on one endpoint or the other
> - software bug on end endpoint or the other (unlikely, everyone else
> would be impacted)
>
>> They show up after a successful ssh login, usually shortly after,
>> sometimes never. The connection can be re-started, but the error
>> persists even after rebooting the remote host.
>>
>> It happens with some hosts and not others, I'm trying to figure
>> out if it's my RasPiOS workstation or the clients (FreeBSD)
>> reporting the error. The IP number shown is of the remote host,
>> but which MAC is being complained about and by whom I can't tell.
>

> In this context ?MAC? means

> https://en.wikipedia.org/wiki/Message_authentication_code, not a network

> card?s MAC address.

Ok, that clears up a profound confusion.

Thank you very much for writing!

bob prohaska