WireSharkPage » History » Version 11
= Extending Wireshark =
The !WireShark packet sniffer normally doesn't support APCO P25. If you want to sniff P25 traffic using !WireShark then you'll need to patch the sources and rebuild it.
=== Downloading !WireShark ===
You first need to obtain the source code for !WireShark. Details of how to obtain source code for !WireShark release versions is available from the [http://www.wireshark.org/download.html downloads section of the WireShark web-site]. Most GNU/Linux distributions provide a source code package and so you should follow the appropriate procedure to download and install the sources.
=== Patching !WireShark ===
Once you've downloaded the wireshark source tree, check out p25 plugin from op25:
(cd wireshark/plugins && svn checkout http://www.sedition.org.au/svn/op25/trunk/wireshark/plugins/p25 p25)
This adds the necessary code to wireshark for it to decode APCO P25 messages. A few small changes also need to be made to the !WireShark tree outside of the plugins directory. To do this the easiest way is to apply the appropriate patch. This can be done as follows:
svn checkout http://www.sedition.org.au/svn/op25/trunk/wireshark/patches .
(cd wireshark && patch -p1 < ../patches/wireshark-1.6.5.patch)
Of course, it is inevitable that you will download a !WireShark version for which we haven't provided a patch. Don't fret - the patches will probably work for your version but if it fails to apply you may need to download one an earlier version of !WireShark for which we have a patch or make the changes manually using the existing patch as a guide.
=== Building + Installing !WireShark ===
The the following command first to resolve the dependancies
(sudo apt-get install bison flex libgtk2.0-dev libpcap-dev)
The standard build for wireshark requires that ./autogen.sh be run first. To compile !WireShark run the following commands:
(cd wireshark && ./autogen.sh && ./configure && make clean && make)
If it compiles cleanly then you can install it as follows:
(cd wireshark && sudo make install)
=== Using !WireShark to sniff P25 ===
Now you've got a modified !WireShark installed it should be a simple matter to start the receiver and use !WireShark to capture its output. To do so simply sniff on your computer's network interface and use the following capture filter: "udp port 23456". At present all P25 traffic is sent to the multicast address 220.127.116.11 so it should be visible on other computers on your subnet - this allows you to sniff in one place and monitor from another.