Aptivate NetGraph

This application has two modes:

• Listening for Netflow traffic, listing flows and graphing them against each other;
• Pinging a server or router, and graphing the ping time

Both are intended as tools for network debugging. Certainly the user interface could be simpler; but the graphical display is an important component in rapidly understanding network conditions:

Running

NetGraph is supplied with an executable JAR file that should work "out of the box":

java -jar target/netgraph-120312-jar-with-dependencies.jar

Unlike on Windows, Java processes on Unix don't usually have enough privilege to send ICMP echo-request (ping) packets: http://bordet.blogspot.com/2006/07/icmp-and-inetaddressisreachable.html

Since many routers don't respond on the echo port, you may need to run the JAR file as root in order to ping:

sudo java -jar target/netgraph-120312-jar-with-dependencies.jar

When it's running, you can type a new IP address into the box at the top.

If it doesn't draw a red line of the ping times, and you see this output in the console:

Pinging at 1331567323204 returned NaN
Pinging at 1331567324214 returned NaN
Pinging at 1331567325216 returned NaN
Pinging at 1331567326217 returned NaN

That means that it needs to be run as root.

Building

If you want to modify the source or rebuild the JAR, use Maven:

mvn

Which should rebuild target/netgraph-120312-jar-with-dependencies.jar.