Cannot connect to my Compute Engine instance - IP is being blocked?

Question

It appears my GCP Compute Engine service/instance/whatever-you-call-it is refusing connections from my machine at times. I was just trying to set up an SFTP connection through a desktop app and probably failed a password too many times.

But I don't have Fail2Ban installed, and I don't see any Firewall Rules in the GCP interface blocking my IP. During what I perceive as the block, I can't even ping the machine. As soon as I switch to my cellphone's hotspot - I can ping it again. See screenshot below - I switched to the hotspot mid-way in that ping.

Does anyone know where I can look to control this setting and/or see what's being done here?

lastb output reflects regular attempts to get into my machine so I don't understand why something is being so harsh on me while this level of spam is flowing to the Linux level at least.

Answer 1

Found the answer - it's sshguard running on linux.

in /var/log/auth.log

Apr 19 01:43:05 x-x sshguard[696]: Blocking "-.-.-.-/32" for 122880 secs (3 attacks in 1 secs, after 11 abuses over 3268716 secs.)