CommView - description from Softdepia.com:
CommView is a program for monitoring Internet and Local Area Network (LAN) activity capable of capturing and analyzing network packets. It gathers information about data passing through your dial-up connection or Ethernet card and decodes the analyzed data.
With CommView you can see the list of network connections and vital IP statistics and examine individual packets. Packets are decoded down to the lowest layer with full analysis of the most widespread protocols. Full access to raw data is also provided. Captured packets can be saved to log files for future analysis. A flexible system of filters makes it possible to drop packets you don't need or capture only those packets that you wish to capture.   Capture Internet and/or LAN traffic passing through your Ethernet card or dial-up adapter.
CommView designed for Internet users and small and medium-sized networks and can run on any Windows 95/98/Me/NT/2000/XP system. It requires an Ethernet or Wireless Ethernet network card supporting the NDIS 3.0 driver standard, or a standard dial-up adapter.
CommView features full decoding of the following protocols: ARP, BCAST, BGP, BMP, CDP, DHCP, DIAG, DNS, EIGRP, FTP, GRE, HTTP, ICMP, ICQ, IGMP, IGRP, IPsec, IPv4, IPv6, IPX, HSRP, NCP, NDS, NetBIOS, NFS, NLSP, OSPF, POP3, PPP, PPPoE, RARP, RADIUS, RDP, RIP, RIPX, RPC, RSVP, RTSP, SAP, SER, SMB, SMTP, SNA, SNMP, SOCKS, SPX, TCP, TELNET, TFTP, UDP, VTP, WAP, WDOG, 802.1Q, 802.1X. More protocols coming soon!
Additionally, our new remote monitoring technology allows CommView users to capture network traffic on any computer where Remote Agent is running, regardless of the computer's physical location. To take advantage of this unique feature, you need to deploy CommView Remote Agent
What you can do with CommView
View detailed IP connections statistics: IP addresses, ports, sessions, etc.
Reconstruct TCP sessions.
View IP protocols and sub-protocols "pie" charts.
Monitor bandwidth utilization.
Browse captured and decoded packets in real time.
Search for strings or hex data in captured packet contents.
Log individual or all packets to files.
Load and view capture files offline.
Export capture files to the HEX, text, NI ObserverŽ, or the NAI SnifferŽ file formats, import capture files from the MS NetMon, Tcpdump, NI ObserverŽ, or the NAI SnifferŽ file formats.
CommView is a "Free to try" program. You can download and try it for an evaluation period.