How do I ssh from one VM to another?

[Knight0Light]

Dear Proxmox users,
I am trying to learn ansible by setting up an ansible environment at home, but I have run into an issue, none of my proxmox hosts seem to be able to ssh into eachother. Trying to ssh with either the hostname I assigned them returns a "could not resolve hostname: Name or service not known" error.
Trying to ssh with the IP address I get from ifconfig returns a "connection to host: connection refused" error.
I have 5 hosts, including the ansible control node, and ssh-ing between them is essential to using ansible. It doesnt seem like there is any reason the ssh should break, what am I doing wrong here? I am brand new to setting up any kind of network, so I am sure I have missed something obvious.

 

[Dunuin]

Did you change any firewall rules? By default port 22 is covered by the hidden anti-lockout rules and should always be open.
Do you try to login as root? Have you done any changes to your sshd_conf?
With a default PVE installation "PermitRootLogin yes" should be set so root is allowed to login via SSH using a password (which for example wouldn't be the case with a default debian).

 

[Knight0Light]

Did you change any firewall rules? By default port 22 is covered by the hidden anti-lockout rules and should always be open.
Do you try to login as root? Have you done any changes to your sshd_conf?
With a default PVE installation "PermitRootLogin yes" should be set so root is allowed to login via SSH using a password (which for example wouldn't be the case with a default debian).

I have not changed any firewall rules (though I wasted a good bit of time trying to figure out how after misinterpreting your answer lol).
I also have not changed my sshd_conf (no idea what that is or where to find it).
I likely used the default PVE installation, and attempting to ssh while logged in as root gives the same connection refused error.

 

[Knight0Light]

I have not changed any firewall rules (though I wasted a good bit of time trying to figure out how after misinterpreting your answer lol).
I also have not changed my sshd_conf (no idea what that is or where to find it).
I likely used the default PVE installation, and attempting to ssh while logged in as root gives the same connection refused error.

I have done some more research and discovered that my VM's had their firewall's Input Policy set to DENY. I have fixed this and it is now set to ACCEPT.
I have also checked every VM and ufw's status is inactive.
I checked the ssh_config.d file on my VMs and its contents are attached. Is anything amiss in this file perhaps?
Please help, I still have no idea why I cannot ssh from one VM to another.