If you've ever been responsible for a network, you know that sinkingfeeling: your pager has gone off at 2 a.m., the network is broken, and youcan't figure out why using a dial-in connection from home. You driveinto the office, dig out your protocol analyzer, and spend the next fourhours trying to put things back together before the staff shows up forwork.

When this happens, you often find yourself looking at the low-level gutsof the Internet protocols: you're deciphering individual packets, tryingto figure out what is (or isn't) happening. Until now, the only realguide to the protocols has been the Internet RFCs — and they're hardlywhat you want to be reading late at night when your network is down. There hasn't been a good book on the fundamentals of IP networking aimed at network administrators — until now.

Internet Core Protocols: The Definitive Guide contains all theinformation you need for low-level network debugging. It providesthorough coverage of the fundamental protocols in the TCP/IP suite: IP,TCP, UDP, ICMP, ARP (in its many variations), and IGMP. (The companionvolume, Internet Application Protocols: The Definitive Guide,provides detailed information about the commonly used applicationprotocols, including HTTP, FTP, DNS, POP3, and many others). It includesmany packet captures, showing you what to look for and how to interpretall the fields. It has been brought up-to-date with the latest developments in real-world IP networking.

The CD-ROM included with the book contains Shomiti's "Surveyor Lite," apacket analyzer that runs on Win32 systems, plus the original RFCs,should you need them for reference. Together, this packageincludeseverything you need to troubleshoot your network — except coffee.