Network Troubleshooting Guide


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Network Troubleshooting Guide

  1. 1. ® Network Troubleshooting Guide 6408 216th St. SW | Mountlake Terrace, WA 98043 | USA | Tel: +1 (425) 778.7728 | Fax: +1 (425) 778.7727 ®
  2. 2. Integrator Series: Network Troubleshooting Guide Useful Troubleshooting Information There are many tools that can help both users and devel- opers to ascertain problematic areas for troubleshooting. Though they can ultimately be quite complex, in their simplest form they are often very easy to use. A few of these are listed below. Msinfo32 This handy little tool displays a comprehensive view of your hardware, system components and software envi- ronment in a simple GUI. It could be helpful in relaying information about your system that might be useful to a Technical Support Staff person. It also already exists on your Windows computer and there is nothing to down- load. 1. From Start, choose Help And Support. Now, all of the information pertaining to the Ethernet adapter for this machine can be stored as a text file and 2. Under the Pick A Task heading on the Help And Support e-mailed to Symetrix Technical support. It’s one more Center page, click Tools. piece of the puzzle that can potentially help us help you. 3. On the Tools page, select My Computer Information in the Two other noteworthy tools that do similar things to Tools column. msinfo32 are listed below. The differences are: 1) they 4. On the My Computer Information page, select any of the links need to be downloaded, installed and ran 2) the GUIs to view a graphical report of your system (View Advanced are much nicer and 3) they generally supply even more System Information is the most inclusive, and you can choose detailed information, particularly concerning network set- what you will look at). tings and activity. More information about each of them OR and downloads can be found at the links below... Start > Run... type “msinfo32” and press ENTER TCPView Once the System Information window is open, there are a myriad of places one can look and see all kinds of things related to the system. Of particular interest, under the Components tree would be Network and Ports. One can save a file including all of the computer information (click File, choose Save and name the .nfo file to be stored in a memorable location) or just certain areas of interest. For example, with the Components/Network tree expanded, click the Adapter subcategory to display the information. ties/tcpview.mspx With Adapter highlighted, click File at the top and choose Export from the list of options. 6408 216th St. SW | Mountlake Terrace, WA 98043 | USA | Tel: +1 (425) 778.7728 | Fax: +1 (425) 778.7727 ® 2 Page
  3. 3. ® Windows® Network Monitor Driver and Task Manager Resetting the PC’s network configuration Start by directly plugging the host computer directly to the Ethernet port of the device. At the host computer, click Start > Run... type “cmd” (without the quotes) in the Run field and press Enter. Once the DOS window appears, type “ipconfig /release” and press Enter (this clears current configurations for the network device). Windows will display your IP settings with all ZEROES in the address fields. Then type “ipconfig /renew” and hit Enter (this causes Windows to reassess networking topology and assign itself a default IP ad- Windows Network Monitor Driver (available from your dress). By doing this, we level the playing field for the Windows Installation media) adds a networking tab to host computer and the device. Now, the direct connection the Windows Task Manager to display network traffic. between the two should result in an effortless discovery / connection process. What to do if the Integrator Series If after doing this the host IP address is not a 169.x.x.x device and PC can’t see each other address, further steps can be taken to make it so. In a worst-case scenario, getting the host machine and Click Start and choose My Network Places. In the column the device to map to the same network is not terribly dif- at left, click View Network Connections. ficult, but requires some PC settings and a reinitialization to the factory default state of the device. If it becomes necessary to re-initialize the device, all user-defined settings and configurations will be lost, so be sure to back-up the device’s files. Reinitializing the device The main advantage of resetting the device to a factory default state is that it will re-enable DHCP (Dynamic Host Control Protocol) on the device, thereby automatically assigning a reliable and predictable IP address in the 169.x.x.x base. The factory reset button is located just to the left of the device’s Ethernet port. Using a pen or a paper clip, depress this button and continue to hold it down. While doing this, unplug the device, wait about 10 seconds and then plug the device back in... continue to keep the reset button depressed until the device has gone through a “light show,” where all of the LEDs on the device briefly light in sequence. Once the light show stops, release the reset button. The device is now returned to the state it was in when it arrived from the factory. 3 Page
  4. 4. Integrator Series: Network Troubleshooting Guide Once the Network Connections are displayed, right-click The user now has the option to declare a specific IP ad- the desired connection and choose Properties from the dress, Subnet Mask and Default Gateway. To do this, make dropdown. sure the “Use the following IP address” option is chosen and enter the information depicted below: When the Local Area Connection Properties window ap- pears, scroll to the bottom of the list, highlight Internet Protocol (TCP/IP) and click the Properties button. 6408 216th St. SW | Mountlake Terrace, WA 98043 | USA | Tel: +1 (425) 778.7728 | Fax: +1 (425) 778.7727 ® 4 Page
  5. 5. ® Using a Packet Sniffer to help If a second Security window should pop up, please click the Run button. troubleshoot connection issues By far, the most useful tool in troubleshooting Network issues is a packet sniffer. The benefit of installing a packet sniffing application would be to help Symetrix engineers and Technical Support troubleshoot and understand any connection issues you may be experiencing with your Symetrix devices. In most cases, a very short record- ing will capture and display enough information for a Symetrix engineer to scrutinize and begin diagnosing a problem, if not fix it outright. If you do not have Administrative rights on the machine Next, the Wireshark Setup wizard will appear. Click the you are working on, either go to a machine you do have Next button. Admin rights on, or please let your Network Administrator Agree to Wireshark’s License Agreement by clicking the I know what you are about to do. Agree button. Installing Wireshark For the Choose Components window, we recommend just Start by going to and clicking keeping the default settings and clicking the Next button. on the DOWNLOAD link near the top of the page. ( or The main link at the top of the download page is for Win- dows 2000/XP/2003 and Vista. Please click this download link. (Be aware: Internet Explorer likes to protect you and your PC, so you may have to click on a pop-up bar at the top of the browser to allow the file to be downloaded) A download window should appear shortly... if not, there is a “direct link” that can be clicked on as well. When the installer window pops up, click the Run button. 5 Page
  6. 6. Integrator Series: Network Troubleshooting Guide Again, best to leave default settings for Additional Tasks When the WinPcap Installer Wizard pops up, click the and click the Next button. Next button. When the WinPcap Setup Wizard pops up, click the Next button. Please agree to the License Agreement by clicking the I Agree button. Once the Setup Wizard is complete, please click the Finish button. You will be automatically returned to the Wire- shark install process. Once the Wireshark Setup installation is complete, please click the Next button. The Install Location destination folder is the Program Files folder on the C: drive. If you’d like to change this, click the Browse button and choose an alternate location for the install. Then click the Next button. At this point, a dialogue prompting to install WinPCap will appear (unless, it is already installed on the PC in question). This is Windows Packet Capture software and is necessary for Wireshark to do its job. There is also an option to start the WinPcap service at Startup, so users without Administrative rights can capture packets. If you Upon completing the setup wizard, the user can check happen to fall in this category, please check this box and a box to launch Wireshark right away. Please do so and click the Install button. click the Finish button. Using Wireshark to capture packets There are just a few more steps to complete before we begin recording network traffic with Wireshark. 1. We recommend closing all other applications at this time, especially any connections to the Internet. This helps to keep the gargantuan number of packets recorded to a minimum and aids all the troubleshooters in reading the traffic. 6408 216th St. SW | Mountlake Terrace, WA 98043 | USA | Tel: +1 (425) 778.7728 | Fax: +1 (425) 778.7727 ® 6 Page
  7. 7. ® 2. Wireshark needs to know where to look for packet traffic. At 4. When the area of trouble or impasse is reached, stop the the main window of the Wireshark Network Analyzer, click packet capture process by clicking the Stop the running live Capture on the menu bar and select Interfaces from the list of capture icon in the Tool bar. options. (Capture> Options: Interface dropdown, promiscuous mode) 5. Once the capture has been stopped, it’s time to save the information in a file that can be e-mailed to Symetrix. Chances are, at least two options are presented. Typically, Click on File in the Menu bar the “...generic dialup and VPN capture” will not apply. and choose Save from the The second option should be the Ethernet card the PC list of options. uses as its information thoroughfare (for Laptops, this may 6. When the Save File As likely be a wireless adapter). The IP address listed next to dialogue window appears, this device should match the IP address of your computer leave all fields at their (if there is any doubt, that IP address is listed on page 2 of default settings (Packet Range information and File the Connection Wizard. If for some reason that cannot be Type) and enter a memorable name for the .pcap file. seen, click Start > Run... type “cmd” and hit Enter > then It might be useful to include your company name or type “ipconfig” in the DOS window that appears.) When some other unique identifier for association. In addi- you are sure of which Capture Interface should be used tion, make sure you know where this file is being saved click the Start button next to the device. so that you can retrieve it for e-mail attachment (the Desktop is always easy to find, for example). That’s it. We are now in a much better position to help you solving any technical difficulties you may be experi- encing concerning Networking troubles related to your Symetrix hardware. Uninstalling Wireshark At this point, Wireshark will begin capturing any travelling The easiest way to uninstall the Wireshark software, packets. should you need to do so, is to click the Start button, 3. Now, Launch the Symetrix application under test. Go choose All Programs, hover over Wireshark and select the through the normal steps of trying to connect to the device. Wireshark Program Directory folder. Once the directory is Wireshark’s top window should be populating with packet open, scroll down until “uninstall.exe” is visible. Double- information. click this executable and the Uninstall Wizard will guide you through the process. 7 Page
  8. 8. ® 6408 216th St. SW | Mountlake Terrace, WA 98043 | USA | Tel: +1 (425) 778.7728 | Fax: +1 (425) 778.7727 Engineered by Symetrix Integrator Series™ Network Troubleshooting Guide © 2008 Symetrix, Inc. All rights reserved. Printed in the United States of America. The information in this document is subject to change without notice. Symetrix, Inc. shall not be liable for technical or editorial errors or omissions contained herein; nor is it liable for incidental or consequential damages resulting from the furnishing, perfor- mance, or use of this material. Mention of third-party products is for informational purposes only and constitutes neither an endorsement nor a recommendation. Symetrix assumes no responsibility with regard to the performance or use of these products. Under copyright laws, no part of this brochure may be reproduced or transmitted in any form or by any means, electronic or mechanical, without permission in writing from Symetrix, Inc. If, however, your only means of access is electronic, permission to print one copy is hereby granted. The following are either Trademarks or Registered Trademarks of Symetrix, Inc.: Symetrix, SymNet, SymNet Designer, SymLink and CobraLink. Windows is a Registered Trademark of Microsoft, Inc.. Other product names mentioned herein may be trademarks and/or registered trademarks of other companies and are property of their respective owners. 6408 216th St. SW | Mountlake Terrace, WA 98043 | USA | Tel: +1 (425) 778.7728 | Fax: +1 (425) 778.7727 ®