Nagios Install: Ports and Firewall

[cchang]

Hello, I did a basic install of Nagios and the web server didn't load after following the installation documentation. I figured out if I disable the iptables, I can login and get a prompt. I want to keep the firewall on so what ports orconfiguration do I need on iptables?
I didn't make any changes to configuration and did a vanilla installaion of CentOS 6.2 x64 so it has the basic firewall rules the install came with.

Thanks!

[cchang]

Ok, I figured out http port 80 is not opened by default. I enabled port 80 on the iptables file. But are there any other ports that need to be opened besides port 80 (http)?

[jsmurphy]

That very much depends on how you are going to do your monitoring.... you will probably want to allow established for 5666 (NRPE), 12489 (Check_NT) and 161 (Active SNMP) you will also want to allow 162 (SNMP Traps) and possibly 5667 (NSCA) from subnets where you expect that kind of traffic. In the unlikely event you are using SNMP with TLS the ports are 10161 and 10162 instead of 161 and 162.