| Before this discussion begins, it might not be a bad idea to review the scientific method. Most high school science students learn that this method has four important steps: 1. | Observe.
| 2. | Hypothesize.
| 3. | Predict based on the hypothesis.
| 4. | Test the hypothesis.
|
The scientific method provides you with a very effective plan for troubleshooting. Too often, administrators are so wound up in their search for a solution that they shoot from the hip, hoping perhaps to stumble on the answer. Sometimes this works. Sometimes, though, you'll encounter a real stumper of a problem, and the standard bag of tricks isn't going to help. This is when the scientific method can really help. The most important part of the scientific method is the observation phase. For the scientific method to work well, you need to have a good set of observation tools. You must carefully observe the conditions that are generating the errors in order to make meaningful predictions. The following sections cover some of the tools that allow you to take a close look at the components in your GroupWise system. Windows Workstations/Servers The following tools are for Windows-based systems: NETSTAT: This utility tells you what ports the local host is listening to, and what ports it's talking to on remote hosts, and what sockets the local host is listening on. Typically you will use the command with the following syntax: netstat -na. IPCONFIG: This command-line version of the WINIPCFG utility tells you vital information about the IP configuration of the local machine. PING: The PING tool allows you to send small packets via TCP/IP to any host on the network or internetwork (or Internet, for that matter). If you can't connect to the POA, you should see whether you can ping it. TRACERT: The tracert command is used to determine how a network packet is being sent and received and the number of hops required for that packet to get to its destination. TELNET: The TELNET tool allows you to open a TCP/IP connection on any port, to any host on the network or Internet. If you can't connect to the POA with the GroupWise client, perhaps you should see whether you can connect to port 1677 (the client/server port) of the POA using the TELNET tool. REGMON: This utility tells you what calls are being made to the Registry. Although it takes some practice to use this tool well, it's great for determining which Registry entries are causing a problem. You can obtain Registry Monitor (REGMON) from www.sysinternals.com. FILEMON: This utility is similar to REGMON, except that it tells you every file on a Windows platform that is accessed. You can obtain this utility from www.sysinternals.com as well.
NetWare Servers These tools will work on your NetWare-based systems: PING.NLM: This is the NetWare version of the PING tool. It allows you to choose the packet size, and will even keep some simple statistical tallies as you ping hosts from the server console. GWIP.NLM: This tool is a little better than a ping, and almost as good as a TELNET. Because there is no true TELNET tool for a NetWare server, GWIP.NLM is an excellent addition to your troubleshooting toolkit. You can download it from www.support.novell.com. Search for GWIP.NLM in the knowledgebase. IPTRACE.NLM: This tool is the equivalent of the TRACERT tool on the Windows platform. It allows you to trace the IP route from a NetWare server. TCPCON.NLM: Load TCPCON and then go to Protocol Information, TCP, TCP Connections. You can determine whether a GroupWise agent is actually listening on a port. MONITOR.NLM: Here you can get an idea of how your system resources are faring. Look at things such as the Disk Cache Utilization and LRU Sitting time. (This is the menu tree on a NetWare 6.0 server.) This value should be well above 15 minutes. You can also determine which server processes are taking up the most CPU time. This is a very powerful and complex tool. CONFIG: This command-line utility tells you vital information about the IP configuration of the NetWare server.
Linux Servers/Workstations These tools will work on your Linux-based systems: Almost all Linux-based commands have a help screen and a man page. To get more help with a command, use the following syntax: command -help or command -h or command --h. To see the man page for a command, use the following syntax: man command. Helpful utilities are listed here: ping: This is the Linux version of the PING tool. It allows you to choose the packet size, and will even keep some simple statistical tallies as you ping hosts from a terminal session. telnet: This tool allows you to open a TCP/IP connection on any port, to any host on the network or Internet. If you can't connect to the POA with the GroupWise client, perhaps you should see whether you can connect to port 1677 (the client/server port) of the POA using the telnet tool. traceroute: The traceroute command is used to determine how a network packet is being sent and received and the number of hops required for that packet to get to its destination. Use the command traceroute h or man traceroute for more documentation on ping. netstat: This utility tells you what ports the local host is listening to, and what ports it's talking to on remote hosts, and what sockets the local host is listening on. Typically, you will use the command with the following syntax: netstat na | grep the port you are looking for. top: Here you can get an idea of how your system resources are faring. ifconfig: This command-line utility tells you vital information about the IP configuration of the Linux host. lsof: Thiscommand-line utility lists the open files on the Linux server. Because in Linux everything is represented as files and folders, you can actually search for ports with the lsof command. An example of looking for the ports that are open is the command lsof | grep LISTEN.
|
