Ansible through Bastion server SSH Error - ssh

Question

Following this guide (and others) running-ansible-through-ssh-bastion-host.
I have my ssh.cfg file set up to allow connecting to a host behind multiple bastions.
proxy -> util -> monitor -> more
I can connect to the util server:
[self#home]$ ssh -F ssh.cfg util
...
[self#util]$
and the monitoring server:
[self#home]$ ssh -F ssh.cfg monitor
...
[self#monitor]$
ssh.conf:
Host *
ServerAliveInterval 60
ControlMaster auto
ControlPath ~/.ssh/mux-%r#%h:%p
ControlPersist 15m
Host proxy
HostName proxy01.com
ForwardAgent yes
Host util
HostName util01.priv
ProxyCommand ssh -W %h:%p proxy
Host monitor
HostName mon01.priv
ProxyCommand ssh -W %h:%p util
ansible inventory file:
[bastion]
proxy
[utility]
util
monitor
ansible.cfg:
[ssh_connection]
ssh_args = -F ./ssh.cfg -o ControlMaster=auto -o ControlPersist=15m
control_path = ~/.ssh/ansible-%%r#%%h:%%p
When I execute any ansible commands, they appear to hit the proxy host without any problem, but fail to connect to the util host and the monitor host.
> ansible all -a "/bin/echo hello"
util | UNREACHABLE! => {
"changed": false,
"msg": "SSH Error: data could not be sent to the remote host. Make sure this host can be reached over ssh",
"unreachable": true
}
proxy | SUCCESS | rc=0 >>
hello
monitor | UNREACHABLE! => {
"changed": false,
"msg": "Failed to connect to the host via ssh.",
"unreachable": true
}
ADDITIONAL:
after some more hacking around, I have key'd the monitor host, and found that ansible can connect to the proxy,and the monitor, but fails on the util host... which is extremely odd because it has to pass through the util host to hit the monitor.
util | UNREACHABLE! => {
"changed": false,
"msg": "SSH Error: data could not be sent to the remote host. Make sure this host can be reached over ssh",
"unreachable": true
}
proxy | SUCCESS | rc=0 >>
hello
monitor | SUCCESS | rc=0 >>
hello

Answer 1

After trying different guides, this solution work for me to use the ansible over the server that doesn't have directory ssh but via proxy/bastion.
Here is my ~/.ssh/config file:
Host *
ServerAliveInterval 60
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
ForwardAgent yes
####### Access to the Private Subnet Server through Proxy/bastion ########
Host proxy-server
HostName x.x.x.x
ForwardAgent yes
Host private-server
HostName y.y.y.y
ProxyCommand ssh -q proxy-server nc -q0 %h %p
Hope that help you.

Answer 2

For some unknown reason Ansible ignores multiple hosts, following config helped me
Host 10.*
StrictHostKeyChecking no
GSSAPIAuthentication no
ProxyCommand ssh -W %h:%p -l ubuntu -i ~/.ssh/key.pem 11.22.33.44
ControlMaster auto
ControlPersist 15m
User ubuntu
IdentityFile ~/.ssh/key.pem