The setup: I host an SSH client (OpenSSH on Windows) and connect to a remote server (I cannot access the server logs). The remote server is used by other organizations with no problems, I can ssh to the remote server from home just fine. When I try to establish a connection from within my organization's firewall, it gets reset by "something" right after the client sends its SSH version but before the server sends its version:
...
debug1: Local version string SSH-2.0-OpenSSH_8.6
kex_exchange_identification: read: Connection reset by peer
There are two firewalls in the middle, and both network admins swear that nothing stops the packets from reaching their destination. The host firewall is off, the AWS security groups are configured correctly.
I looked at the pockets with Wireshark and saw nothing other than RST fromt he server when the connection was reset.
What can it possibly be and how do I troubleshoot it?
EDIT1: Here is another clue: I can ssh to any invalid host and any invalid port and I get the same response. First "Connection established" then a "connection reset". completely confused what can be causing this
The firewall was never opened correctly; the TCP traffic was blocked(despite repeated assurances from the firewall team).
This will help other folks that are in the same situation.