Install sntop on a Mac

sntop running on a Mac inside Terminal

How to install sntop on Mac OS X Lion

sntop (simple network top)

What is sntop?

This is a port of sntop, a curses-based utility that uses fping (ping can be used as well) to determine connectivity of remote network hosts on a regular interval. Features include HTML generation and a secure terminal.

sntop is a CLI *nix based tool which will ping several sites continuously to check if it gives a ping response (if it's up or down). It's also helpful to see if your computer has internet connectivity, for those who have flaky internet.

Pre-Install tasks

1. Download and install MacPorts
2. Once installed check it's up to date

   sudo port selfupdate

3. Install any updates

   sudo port upgrade

4. Install fping, which is needed by sntop

   sudo port install fping

Install sntop

1. Download sntop (Direct Link to 1.4.3 as of 20/10/2011)
2. Extract the downloaded file tar.gz

   tar -zxvf sntop-1.4.3.tar.gz

3. Go into the extracted directory

   cd sntop-1.4.3

4. Configure it with the --prefix switch set to your ports directory

   ./configure --prefix=/opt/local/

• Note: Do a make clean before continuing if you tried to make it without the --prefix option and it failed.

1. make

2. sudo make install

3. If all went ok without any errors you should now be able to run

   sntop

Configuration

• To add sites for it to monitor edit this file

mate /opt/local/etc/sntoprc

Setup a log file

1. Start sntop and execute an .sh script when ever a service goes up or down

   sntop -r 30 -l ~/alarm.sh

2. Use the sample script that came with sntop (I changed the below a bit), save it to to ~/alarm.sh

   #! /bin/sh
   # alarm.sh - Sample script for use with sntop's alarm/log mode
   # rml, 20001022
   
   # sntop supports two-modes, alarm and log, set via:
   #  -a <file>, --alarm=file
   #  -l <file>, --log=file
   # In alarm mode, whenever a site goes DOWN <file> is executed
   # In log mode, <file> is executed on any change in status
   # <file> is given three arguments: the display hostname, the
   #  actual hostname or IP address, and the new status (UP or DOWN)
   
   # This script will log to OUTFILE the time and date, the display
   #  name, and the status of the passed host.  If the host is DOWN
   #  (always the case in alarm mode), an e-mail is sent to root
   
   OUTFILE=$HOME/sntop.log
   
   if [ $3 = "DOWN" ]; then
           echo "sntop detected at `date` that $1 [$2] went $3" | mail -s "[sntop] Host Down!" root
   fi
   
   echo "sntop: `date`: $1 went $3" >> ${OUTFILE}
   
   # EOF
   

3. Run the following in another terminal window to see when something goes down.

   tail -f  ~/sntop.log