1. Troubleshooting TCP/IP COSC513 FALL By :Ming Wei

2. 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.

3. 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.

4. 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.

5. 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.

6. Tools for diagnosis

7. 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

8. n If a device is having problems communication on the network, enter the following command at the DOS prompt: ping 127.0.0.1 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.

9. Another example: (FTP) n Suppose a user on network 130.59.0.0 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.

10. Another example (FTP)

12. 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.