UNIX for Advanced & Expert Users

Hi All,
I need an urgent assistance please .

My case below:
I have a list of 500 IP addresses.
All These ip addresses are mapped/connected to different machine kinds : NT, Linux, Switch, Router ,FW, and so on.

My Requirement is to filter from all this ip address only the Linux machines.
In other words,to create a mapping of all the Linux (Centos) Machines.

Now I do not sure what would be the best way to do it.

In order that operation will performed on a practical way,
i have an central linux server that can be consider as an SSH Server,Although he did not ,Since it still without an organized hosts list of all Linux servers in the organization, and of course it does not connect to all servers without a password.

But for the operation that will needs to perform, this server can communicates on the LAN with all the linux machine with Ping and SSH , with all this Linux servers that exist behind the ip addresses list .

i thought maybe build a bash script , that will runs from the central server, on all the IP Address , and during the action, it will sent the results into a text file , output from the 500 IP Address that it was able to open them session in SSH.
Is this the right way? Is there something else?

Please Assist.