Troubleshooting TCP/IP COSC513 FALL By :Ming Wei

TCP/IP Problems can be grouped into 4 categories n 1. Configuration: n If your network configuration is incorrect, it can result in one or more services not starting when you bring up your NT Workstation or Server.

TCP/IP Problems can be grouped into 4 categories n 2. IP Addressing The host can hang up when trying to communicate with other hosts. This could be caused by the existence of an improper subnet address or duplicate IP address.

TCP/IP Problems can be grouped into 4 categories n 3. Subnet addressing If your host has an improper subnet address assigned to it, it may not be able to talk to other local or remote hosts.

TCP/IP Problems can be grouped into 4 categories n 4. Resolution You can ping a host with an IP address, or connect to a network drive using a host’s IP address, but you cannot establish a connection using only its host name.

Tools for diagnosis

Example (USE PING…) n PING utility can be used to query another IP device on the network and determine if the IP address is “alive”, how long it takes a packet to reach the device. n Syntax: ping [-t] [-a] [-n count] [-1 size] [-f] [-i TTL] [-v TOS] [-r count] [-s count] [-s count] [-j host-list] [-w timeout] destination IP list

n If a device is having problems communication on the network, enter the following command at the DOS prompt: ping The address is the loopback address. So if the device can’t see it’s own TCP/IP stack, the device can’t communication on the network. !!! You don’t want to use the -t parameter unless you want to track and manually terminate the ping test. This parameter cause a continuous transmission of ping packets and may generate significant traffic on the network.

Another example: (FTP) n Suppose a user on network typed the FTP command to begin a file transfer to the CORPFS1 Server. The workstation convert it into a valid packet, it must contains the destination port number, destination IP address, and MAC address.

Another example (FTP)

Conclusion... n Get familiar with all of TCP/IP utilities and keep looking for new tools are the key to troubleshoot TCP/IP based network. n Thank you for your time, and welcome to read my paper and share your comments with me.