【 Weak current College 】 practical network command list (1)

When you open the browser, free to cruising in the vast world of the Internet, is also addicted to download various practical software? which may have a large part of the network tools! but please don't ignore your presence — Windows (including Win98 and NT) for system already comes with many network utilities, although quite simple, but it is not simple. In the spirit of "simple is beautiful" principle, the following is to show you the charm of the Windows network utility ...

Ping
Ping is a very high frequency of use of the utility used to determine whether the local host and another host Exchange (send and receive) datagrams. According to the information returned, you can infer the TCP/IP parameters are correctly set and running correctly. Note: to successfully with another host once or twice a datagram Exchange does not mean that the TCP/IP configuration is correct, you must perform a number of local host and the remote host of the datagram TCP/IP can be sure that the Exchange.

Simply put, Ping is a test program to run properly, if you Ping, you generally can troubleshoot network access layer, network card, MODEM input and output lines, cables, routers, and other existing faults, thereby reducing the scope of the problem. But because you can customize the size of datagrams and endless speed send, Ping also by some people with ulterior motives as DDOS (denial of service attack) tools, some time ago Yahoo is being hackers use hundreds of high-speed Internet access to send a large number of computer continuously Ping the datagram and paralysis.

By default, Windows runs the ping command sends four ICMP (Internet Control Message Protocol) echo request, each 32 bytes of data, if all is well, you should be able to get 4 echo reply.

Ping to milliseconds display send echo request to return back to the time between sending response. If response time is short, which indicates that the data reported having to go through too many router or network connection faster. Ping also can display the TTL (TimeToLive exist time) value, you can use the TTL value projections about packet has passed the number of router: source locations TTL starting value (which is slightly larger than the returns TTL from a number of powers of 2)-returns TTL values. For example, returns the TTL value to 119, then you can calculate the source address of a datagram from a starting value of the TTL is 128, and the source location to the destination location to nine router (128-119); if the TTL value is returned, the starting value TTL 246 is 256, the source location to the destination location to nine router network segments.

By Ping testing network failure of typical order

Normally, when you use the Ping command to locate the problem or test network is running, you need to use many of the Ping command, if all are running correctly, you can believe that basic connectivity and configuration parameter has no problem; if some of the Ping command to run the fault occurs, it can also be specified to where to find the problem. The following is a typical detection order and corresponding may fail:

Ping127.0.0.1--the Ping command is sent to the local computer's IP software that never leave the computer. If you fail to do this, it indicates that TCP/IP is installed or run-there are some of the most basic of questions.

Native IP ping-this command is sent to your computer has been configured with the IP address, your computer always should answer with the Ping command, if not, then the local configuration or installation problem. This problem occurs, the local area network, disconnect the network cable to the user, and then resend the command. If the network cable is disconnected the command correctly, it means that another computer can be configured with the same IP address.

Additional IP ping LAN--this command should leave your computer, go through the NIC and the network cable to reach another computer, and then returns. To receive the echo response indicates that the local network adapter and run the correct carrier. But if you receive 0 echo reply, so that the subnet mask (subnet segmentation, the IP address of the network part and a host part of the separation of the code) is not correct or NIC configuration errors or problems with the cable system.

Ping gateway IP--this command if you answer correctly, said LAN gateway router is running and able to answer.

Ping remote IP--if you get 4 said a successful response, use the default gateway. For dial-up user is able to successfully access the Internet (not excluding the ISP DNS be problematic).

Pinglocalhost--localhost is a systematic network reserved name, it is the alias 127.0.0.1, Pacific computer should be able to put the name into the address. If you do not do this, the hosts file (/Windows/host) problem.

Pingwww.yahoo.com--on the domain name to perform Pin ... Address, usually by a DNS server if it fails, then the DNS server's IP address is not configured properly or the DNS server has a failure (for dial-up users, some ISPs have no need to set up DNS servers). By the way: you can also use the command implements the domain name to IP address conversion function.

If all of the listed above Ping commands properly, then you're on your computer for local and remote communication functionality basically you can rest assured. However, the success of these command does not mean that all you have to ask the network configurationThe title, for example, certain subnet mask errors may not be able to use these methods to detect.

Ping commands commonly used parameter options

PingIP-t--consecutive to the IP address of the ping command, until the user CTRL + C interrupt.

PingIP-l2000--specify the ping command in the data length is 2000 bytes instead of the default of 32 bytes.

PingIP-n--perform a specific number of Ping command.

Netstat Netstat displays andIP, TCP, UDP and ICMP protocol-related statistics, typically used to test a native network connection of the port.

If your computer is sometimes acceptable to datagram will cause an error data deleted or fault, you don't have to feel strange, TCP/IP can allow these types of errors, and the ability to automatically redirect datagram. But if the cumulative number of error situations accounted for received IP datagram considerable percentage, or its number is rapidly increasing, then you should use the Netstat find out why that happens.

Some commonly used options netstat:

Netstat-s--this option to display its individual agreements separately. If your application (such as Web browsers) to run much slower, or Web page cannot be displayed, such as data, then you can use this option to check the information displayed. You need to look closely at the statistics of each row, an error is found, then the keywords determine the problem.

Netstat-e--this option displays Ethernet statistics. It lists the project including the transmission of data reported by the total number of bytes, number of errors, delete number, the number of datagrams and broadcasting. These statistical data are the number of datagrams are sent, the number of datagrams received. This option can be used to count the number of basic network traffic).

Netstat-r--this option to display information about the routing table, similar to the later use routeprint command you see the information. In addition to displaying a valid routing, display the active connections.

Netstat-a--this option displays a list of valid connection information, including the established connections (ESTABLISHED), also including listening connection requests (LISTENING) of those connections.

Netstat-n--displays all valid connection is established.

Artful use of Netstat

Regular Internet use by people generally, ICQ does not know you have been harassed by some pain in the neck onthe line, not afraid to complain but don't know where to start?, and you just have to know each other's IP, to his ISP complaints. But how can we know through ICQ? if the IP of each other when you set ICQ have chosen not to display the IP address, you are unable to see the information bar. In fact, you only need to pass the Netstat can easily do this: when he through ICQ or other tools and you are connected (for example you give him an ICQ message or send you a message), you'll immediately enter the DOSPrompt netstat-n or netstat-a can see each other on the Internet by IP or ISP domain name. Even the Port are fully exposed, if you want to give him some lessons, this information is sufficient ...

IPConfig IPConfig utility and its equivalent graphics user interface — Windows95/98 in WinIPCfg can be used to display the current TCP/IP configuration settings. This information is generally used to verify the TCP/IP settings of artificial configuration is correct. However, if your computer and is located in the LAN uses the Dynamic Host Configuration Protocol (DynamicHostConfigurationProtocol, DHCP--WindowsNT under a less IP address assigned to a number of hosts using Protocol, similar to a dial-up Internet access dynamic IP allocation), this program displays information perhaps more practical. At this point, the IPConfig can show you your computer is successfully rented to one IP address, if rented to you can understand how it is currently assigned to any address. Learn about your computer's current IP address, subnet mask, and default gateway actually testing and failure analysis of necessary items.

The most common options:

Ipconfig--when you use IPConfig without any parameters, it is already configured for each interface displays the IP address, subnet mask, and default gateway values

Ipconfig/all--when you use the all option, IPConfig to DNS and WINS servers configured and show it to be used for additional information (such as IP address, etc.), and display built into the local network adapter's physical address (MAC). If the IP address lease from a DHCP server, IPConfig displays DHCP server's IP address and leased addresses projected date of failure (the DHCP server related content please see the other books about NT Server or ask your network administrator), its output information see the lower part of Figure 6.

Ipconfig/release and ipconfig/renew--these are two additional options, only to the DHCP server leases an IP address of the computer. If you enter ipconfig/release, all interfaces of leased IP address will make it againPaid to the DHCP server (the returned IP address). If you enter ipconfig/renew, then the local computer will try to get in touch with the DHCP server, and leased an IP address. Please note that in most cases, the card will be given and before the same IP address.

If you are using Windows95/98, then you should be more accustomed to using ipconfig winipcfg instead, because it is a graphical user interface, and the information displayed is the same as with ipconfig, and also provides publishing and updating a dynamic IP address option if you have purchased a WindowsNTResourceKit (NT Resource Kit), WindowsNT also contains a graphical alternative interface, the utility's name is wntipcfg, and Windows95/98 winipcfg.