AboutCarolyn Meinel Expertise I cover Windows, Unix, TCP/IP and Ethernet security questions. I do not cover Mac, Palm Pilot, or other networking issues.
Experience Books by Carolyn Meinel: wrote a chapter for The Hacking of America book (see http://www.amazon.com/exec/obidos/ASIN/1567204600/happyhacker)
My article Code Red for the Web for Scientific American was reprinted in the book Best American Science Writing 2002 (see http://www.amazon.com/exec/obidos/ASIN/0060936509/happyhacker). My book The Happy Hacker: A Guide to Mostly Harmless Hacking is now in 4th edition with a Japanese edition (see http://happyhacker.org/hhbook/).
Question i can ping servers on the subnet my workstation is on but not other subnets.why?
Answer Your network has been set up to prevent pinging outside your subnet. How exactly this has been done depends upon your particular network. You can find out how this is being done by asking the person in charge of your network.
If you really, really want to detect computers on other subnets of yoru network, some of the options in nmap (free from insecure.org) will probably work. However, there is a possibility that the administrator of the network you are testing will detect your use of nmap and get you fired or kicked off the network for unauthorized hacking. So if you decide to try out nmap, be careful to first get permission from the person in charge of this network.
