Ansible all -m ping ad hoc command doesn't complete, it times out after 10 minutes

Don't see too much traffic here on Ansible, however still wanted to see if others know of this issue.

I run ad-hoc commands to test if servers are up and check their stats. Right now I have 5 servers in my host file. The other day when I ran the following:

Code:ansible-all -m pingAll of them ping back, except for one.

Same result if I run the following command

Code:ansible all -m command -a 'uptime' -oI've setup logging for ansible under /var/log, nothing odd shows up. Other then I let this command run and then it times out after 10 minutes, with the following output:

Code:Failed to connect to the host via ssh: mux_client_request_session: session request failed: Session open refused by peer

ControlSocket /home/user_a/.ansible/cp/ceeab067b3 already exist, disabling multiplexing

Connection to 10.x.x.x closed by remote host.I can ping this workstation and ssh into it with no issues while this ad-hoc command is hung. So access and network connectivity is no issue.

Ironically we have to reboot this workstation and now the ad-hoc command works, but I don't want to rely on a reboot to fix things. Want to know why things aren't working.

Has anyone seen this and what actions did you take to fix it?

thanks