This is the official web site of tcpdump, a powerful command-line packet analyzer; and libpcap, a portable C/C++ library for network traffic capture.
The Wireshark / DHCP explorer / DHCP Probe approaches are good for a one time or periodic check. However, I'd recommend looking into DHCP Snooping support on your network. This feature will provide constant protection from rogue DHCP servers on the network, and is supported by many different hardware vendors. Hard One!! network related to tcpdump and a batch file i am creating a batch file that will map switch ports from the host computer by generating CDP packets. i have created to have 2 option first is to do a single computer which will work find the second is two perform this on a list that can be found in a text file. my issue is that when a generate the CDP packets i have to know what interface is active. so i use a switch from tcpdump that lists InfoSec Handlers Diary Blog
TCPDUMP/LIBPCAP public repository
12 Tcpdump Commands - A Network Sniffer Tool Capture Packets from Specific Interface. The command screen will scroll up until you interrupt and … TCPDUMP/LIBPCAP public repository This is the official web site of tcpdump, a powerful command-line packet analyzer; and libpcap, a portable C/C++ library for network traffic capture.
Gets the CDP information from a Windows computer with
BTSoftware Software Registration Service, Voice: +31 40 MicroOLAP TCPDUMP for Windows may be run from any removable device without installation on the user's PC: it is compiled with Packet Sniffer SDK, so no any pre-installed third-party packet capture drivers are required. Just run tcpdump.exe, and use tcpdump command-line interface you're already familiar with. Performance Packet fragmentation versus the Intrusion Detection System Apr 19, 2007