عیب یابی ویندوز با داس! Troubleshoot Your WinXP

واضح آرشیو وب فارسی:سایت ریسک: Vahed28-07-2007, 10:29 PMIt’s probably happened to you at least once—you sit down in front of the computer to browse the Web or check email, only to discover that your system doesn’t appear to be connected to the Internet. That’s an easy conclusion to come to, but it’s a bit more difficult to figure out exactly why you can’t connect and what you should do to fix it. Windows XP includes two network utilities, Ipconfig and Ping, that can help. Although both are command-line utilities, both can be enormously helpful in identifying the cause of and solving a network problem. Ipconfig Whenever you’re having a problem connecting to the Internet, the first step toward resolving the problem is to verify that your system has a valid IP (Internet Protocol) address. This is easily accomplished using Ipconfig (IP Configuration), a utility that lets you determine whether TCP/IP (Transmission Control Protocol/Internet Protocol; a language that controls communications among computers on the Internet) is running and correctly configured on your computer. To run Ipconfig, you need to first access a commandline window, which you can do by clicking Start and then Run, typing CMD, and pressing ENTER. In the command line window, type IPCONFIG and press ENTER to see basic IP configuration data for each network adapter installed on your system. This information includes the adapter’s IP address, subnet mask, and default gateway. Most home computers are connected either directly to a cable/DSL (Digital Subscriber Line) modem or to a router (which in turn is connected to the cable/DSL modem) and typically get their IP addresses automatically from one of those devices (the one it’s directly connected to) via DHCP (Dynamic Host Configuration Protocol). When TCP/IP is correctly configured, you should see entries under all three Ipconfig headings: IP Address, Subnet Mask (almost always 255.255.255.0), and Default Gateway. In most cases when there’s a router on your network, the computer’s IP and default gateway addresses will both begin with 192.168—only the last numbers of the address should be different. Identifying Problems There are a number of warning signs in Ipconfig that indicate an IP configuration problem. If Ipconfig reports your network adapter’s IP address as 0.0.0.0 or if the address starts with 169.254, it usually indicates that your system requested an IP address but didn’t get one for some reason, which does happen from time to time. To manually issue a new address request, type IPCONFIG/ RELEASE to reset the connection; when the command prompt reappears, type IPCONFIG/RENEW. In many cases, this will resolve the connection problem, but another option is to right-click the adapter’s icon in Network Connections and choose Repair. This will not only reset and renew the IP address request, but also disable and re-enable the adapter itself. If your adapter doesn’t list any IP information but instead reports Media Disconnected, it probably means your network cable has become detached or that the router or cable/DSL modem at the other end of the cable isn’t plugged in or powered on. (In the case of a wireless network adapter, this message means that you’re not connected to the wireless network.) You’ll need to rectify these issues before attempting to obtain an IP address. Ping Ping is a simple utility that tests the network connection between two computers. This makes it an extremely valuable tool to help isolate a connectivity problem and determine whether it lies with your equipment, your ISP’s (Internet service provider’s) equipment, or somewhere on the ISP’s network. Once you’ve used Ipconfig to make sure your system’s IP configuration is correct, the next step is to use Ping to methodically test the connection along various points along the link from your computer to the Internet. As with Ipconfig, it’s best to launch a command line window, so the results of the command stay on your screen long enough for you to read them. If you use a software firewall, it’s also important to disable it before using Ping because the default configuration of most software firewalls will suppress Ping responses, rendering it useless as a diagnostic tool. Step 1. The first link in the chain to ping is your computer’s internal TCP/IP connection. You can do this by typing PING, a space, and then 127.0.0.1. Press ENTER. The address 127.0.0.1, also known as the loopback, is a special address which is a stand-in for your computer’s real IP address. Alternatively, you can enter your computer’s actual IP address or localhost—all three are equivalent. After you execute the Ping command, you should receive four replies in rapid succession formatted as follows: Reply from 127.0.0.1: bytes=32 time<1ms TTL=128 followed by some summary information. (If you ping your actual IP address, the response will come from that address instead of the loopback.) Step 2. The next link to test is the connection between your computer and the router or the cable/DSL device it’s connected to. In either case this device is known as your default gateway—its IP address can be found under that heading when you run Ipconfig. (If your system is connected to a router, the address is usually 192.168.1.1 or 192.168.0.1, but if your system is connected directly to a cable/DSL modem, it may be something else.) When you ping your network’s default gateway, you should receive four prompt replies from that address, much as you did when you tested your system’s internal connection. If you don’t get those replies and instead receive Destination Host Unreachable or Request Timed out, it probably means that the device is disconnected or malfunctioning. Checking the network and power cables and/or restarting the device will often clear up the problem. Step 3. If you were testing the connection to a router in the previous step, the next connection to test is the one to your cable/DSL modem. (If your system is connected directly to your cable/DSL modem, skip this step.) When a cable/DSL modem is connected to a router instead of to a PC, you can’t get its IP address via Ipconfig. The best way to get it is to log in to your router’s administration console and look it up on the router’s status screen. It’s usually listed as the Internet or WAN address, but because routers vary as to where they display this information, check your device’s manual on how to find it.) After you’ve located your cable/DSL device’s IP address, ping it just as you did the previous addresses. If you don’t get replies, check the network and power cables and restart both your cable/DSL modem. If this doesn’t restore your connection, a call to your ISP is probably warranted. Step 4. After you’ve successfully pinged all the devices on your premises, the final step is to try to ping an address on the Internet. (Trying to access a Web page is often a reliable indicator of connectivity, but it isn’t conclusive because the problem could be with your browser or the specific site.) To verify that your system is reaching the Internet, ping a Web site you frequently visit. It’s not necessary to know the actual IP address of the site; using a friendly name such as Yahoo! (!!!! برای مشاهده محتوا ، لطفا ثبت نام کنید / وارد شوید !!!!) is fine. Because you’re only trying to verify a connection to the Internet, not necessarily a specific site, you don’t need to include www in the address; it doesn’t matter if you do include it, though the reply might appear to come from a slightly different address from the one you pinged depending on how the site has been set up. To do so, at the command prompt, type ping yahoo.com and press ENTER. Many major Web sites intentionally don’t reply to pings. If you don’t get a reply when pinging a site, check to see whether the response includes the site’s numerical IP address. If it does, this indicates your Internet connection is working because that address must be looked up from a DNS (Domain Name Server) on the Internet. If you don’t get a reply to a ping command and the response doesn’t include the IP address of the site you pinged, it probably means your ISP is having network problems, and you’ll need to get in touch with it سایت ما را در گوگل محبوب کنید با کلیک روی دکمه ای که در سمت چپ این منو با عنوان +1 قرار داده شده شما به این سایت مهر تأیید میزنید و به دوستانتان در صفحه جستجوی گوگل دیدن این سایت را پیشنهاد میکنید که این امر خود باعث افزایش رتبه سایت در گوگل میشود

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