An existing connection was forcibly closed by the remote host

I get intermittent exceptions when connecting to an sftp server. I connect once every minute and most of the time it works just fine but a couple of times each day I get "An existing connection was forcibly closed by the remote host".

Looking at it in Wireshark I see the following when things go wrong:

743 2023-02-16 12:54:10,515128 22 TCP 66 57582 → 22 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 WS=256 SACK_PERM=1
744 2023-02-16 12:54:10,538824 57582 TCP 66 22 → 57582 [SYN, ACK] Seq=0 Ack=1 Win=29200 Len=0 MSS=1390 SACK_PERM=1 WS=128
745 2023-02-16 12:54:10,538914 22 TCP 54 57582 → 22 [ACK] Seq=1 Ack=1 Win=262656 Len=0
746 2023-02-16 12:54:10,539031 22 SSHv2 92 Client: Protocol (SSH-2.0-Renci.SshNet.SshClient.0.0.1)
747 2023-02-16 12:54:10,561823 57582 TCP 60 22 → 57582 [ACK] Seq=1 Ack=39 Win=29312 Len=0
748 2023-02-16 12:54:10,566251 57582 TCP 60 22 → 57582 [RST, ACK] Seq=1 Ack=39 Win=29312 Len=0

But most of the time it looks like this, which is fine:

749 2023-02-16 12:54:20,580048 22 TCP 66 57584 → 22 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 WS=256 SACK_PERM=1
750 2023-02-16 12:54:20,606751 57584 TCP 66 22 → 57584 [SYN, ACK] Seq=0 Ack=1 Win=29200 Len=0 MSS=1390 SACK_PERM=1 WS=128
751 2023-02-16 12:54:20,606826 22 TCP 54 57584 → 22 [ACK] Seq=1 Ack=1 Win=262656 Len=0
752 2023-02-16 12:54:20,606989 22 SSHv2 92 Client: Protocol (SSH-2.0-Renci.SshNet.SshClient.0.0.1)
753 2023-02-16 12:54:20,630003 57584 TCP 60 22 → 57584 [ACK] Seq=1 Ack=39 Win=29312 Len=0
754 2023-02-16 12:54:20,644309 57584 SSHv2 75 Server: Protocol (SSH-2.0-OpenSSH_8.0)
755 2023-02-16 12:54:20,688760 22 TCP 54 57584 → 22 [ACK] Seq=39 Ack=22 Win=262656 Len=0

If I switch to WinScp or Rebex it works without any issues.

Il report non indica alcun file del repository, test o punto di ingresso del codice. Inizia riproducendo connessioni SFTP ripetute e confrontando le tracce della negoziazione SSH delle connessioni riuscite e di quelle reimpostate; determina se SSH.NET o l’host remoto causa la chiusura intermittente. Il lavoro è completato quando la causa è stata stabilita ed è stata documentata una correzione verificata o una limitazione attuabile.