[Check_mk (english)] Cannot check ESXi 5.5 hosts, vsphere

[Alan Murrell]

Hello,

I have a vSphere 5.5 with three ESXi 5.5 hosts.  I have the latest OMD 
installed.

I am following <https://mathias-kettner.de/checkmk_vsphere.html> and 
adding through WATO.  I create the datasource program, specify the IPs 
of my hosts and the login information for each host.  I am retrieving 
all information and setting type of query to "host system"

When I add the host itself in WATO, I am selecting the agent type as 
"Check_MK Agent (Server)", but when I click "Save and go to Services", 
it errors out, saying it cannot connect to to port 6556.

I am obviously missing at least one step here, but I have gone over and 
over the <https://mathias-kettner.de/checkmk_vsphere.html> page any my 
configuration and cannot see what I am missing.

Thanks, in advance, for your assistance.

-Alan