Please note, this page is under development at the moment and may be incomplete or possibly use incorrect terminology
When users encounter issues, there are a number of steps that can be taken to collect information surrounding the issue. Steps here should contain no compiling.
Using a port mirror in an intelligent switch is the most effective way of capturing the traffic to/from a PXE client. Cisco Catalyst switches running IOS use "port monitor" and/or "monitor session". Cisco Catalyst switches running CatOS (CatalystOS) use "span" (short for "Switch Port ANalyzer). Some HP switches use "traffic mirroring" and "traffic monitoring".
Once a mirror of the PXE client's port is configured, the capture interface on the machine doing the capture should be as silent as possible to prevent unwanted packets from being captured.
For a PXE client that can successfully use DHCP to identify the characteristics it should use (including the server and filename to boot), capturing traffic from the machine running the tftpd is pretty effective. Most tftpds will move to another port for the actual data transmission but the PXE client's IP should be in all of the applicable traffic. Filtering to just packets with that IP will likely suffice.
Using wireshark with a capture filter of 'host 192.0.2.16' (assuming 192.0.2.16 is the PXE client) will generally capture all relevant packets and no irrelevant packets.
An example tcpdump command: `tcpdump -i eth0 -w dump.cap 'host 192.0.2.16'`