How to install nTOP 4 on CentOS 6 by RPM

nTOP is a Network Tap program. It displays a summary of network usage by machines on your network in a format reminiscent of the unix top utility. It can also be run in web mode, which allows the display to be browsed with a web browser.
1. Install RPMforge repo :
# rpm -ivh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm
Note : you can find the lastest of rpmforge repo at http://pkgs.repoforge.org/rpmforge-release
2. Install necessary packages for nTOP :
# yum install graphviz rrdtool rrdtool-devel geoip geoip-devel net-snmp-libs gdbm gdbm-devel
3. Install nTOP :
# cd /usr/src
# wget http://dl.marmotte.net/rpms/redhat/el6/x86_64/ntop-4.0.3-1.el6/ntop-4.0.3-1.el6.x86_64.rpm
# rpm -ivh ntop-4.0.3-1.el6.x86_64.rpm
# chkconfig ntop on
4. Set Admin password :
# ntop -A
5. Start nTOP service :
# service ntop start
6. Confirm nTOP is working :
# lsof -i :3000
# lsof -i :3001
Note : TCP 3000 for HTTP and TCP 3001 for HTTPs
7. Secure ntop access from outside :
a. Browse to https://ip-address.your.nTOP.server:3001
b. Click “Admin” > “Configure” > “Protect URLs”
c. Enter username “admin” and your password (set in step 4 above) when prompted.
d. Click “Add URL” then “Add URL” again.
NOTE: This will require a username and password to access https://ip-address.your.nTOP.server:3001

source  :  http://saroot.org/blog/how-to-install-ntop-4-on-centos-6-by-rmp-package/