Ports & Services
I am in the process of trying to document all required ports & services for normal or emergency operations only.
This is a fairly difficult task considering the number of ports & services.
I am running RHEL 6 workstations right now and they have all of the ports & services documented in /etc/services.
The workstations will not be connected to the internet and we would only need to connect externally to it through vnc or ssh.
Its only external communication it would have comming into the box would be from one server.
I don't want to start commenting out services in the etc/services file or researching everyone to see if it is neccessary.
I am wondering if anyone else has came accross a scenario like this and if they have an ideas on the best way to do this.
If I confused anyone just let me know and I can clarify.
The best way to make sure you don't have any unnecessary services running is at install time. If you want to turn off services during start up, the easiest way to do that is with chkconfig.
Unless you're trying to accomplish something specific, I'm not sure how much help anyone can be to you. Only you will know what you need and what you don't need.
As it happens, I stumbled across the following information while looking to help on another topic:
CentOS Init startup scripts - Support Documentation
The last section of that page lists a few services you can probably disable if you're trying to get your running services count down :)
This will show you some commands that will let you check what is up and listening on what ports.
Red Hat / CentOS: Check / List Running Services