Splunk can enable you to quickly find and parse data, however you often need to send the data to something like graphviz so that I can see it.
I've written an app that adds a new search command to Splunk that will enable you to generate a graph from your search data.
* | viz field1=ip1 field2=ip2 label=proto flatten=true file=/tmp/network1.png
* | viz field1=ip1 field2=ip2 label=proto flatten=true file=/tmp/network2.png rankdir=RL
One of the nice features is that you can add graphviz options directly to the command i.e. rankdir=RL
The app can be obtained via http://github.com/marinus, comments & patches are welcome.