Regarding XP, "There are duplicate names on the network"

Source: Internet
Author: User
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Some machines in the company's LAN have a "Duplicate name on the network" problem when they start up. If you can ping other machines in the Intranet, it is normal to connect to the Internet and the computer name cannot be modified. This problem also occurs in my virtual machine.

Solution:

1. Open Network Connection Properties on this XP computer, and then open the properties of the NIC-> TCP/IP properties-> advanced.
2. Remove unnecessary wins addresses under the WINS tab.
3. Disable LmHosts lookup.
4. Set NetBIOS to disabled. (NetBIOS is required for network neighbors. If NetBIOS is disabled, the network neighbor working group cannot view any computers)

NetBIOS Name

1.1 define the computer name (NetBIOS name)

NetBIOS is a high-level language interface for MS-DOS programs that emerged in late 1980s to build a LAN Using ibm pc. To connect these computers together to form a LAN Using network hardware and software, Microsoft and other vendors use netbios interfaces to design their network components and programs. The NetBIOS interface uses a name up to 16 characters to identify each network resource.

The NetBIOS name is unique in a network. NetBIOS will be dynamically registered to the database when the computer is started, the service is activated, and the user logs on to the network. NetBIOS can be registered as an independent name or a group name. When registering with a single machine name, there must be an IP address corresponding to it. For example, when registering with a group name, multiple IP addresses correspond to it.

All MS-DOS-based and Windows-based operating systems prior to the launch of Windows2000 need to use the NetBIOS name interface so that the network can work properly. With the release of windows, computers on the network no longer need the NetBIOS Name Interface. For example, in windows and Some UNIX networks, they only require the client to support DNS, and no NetBIOS name is required. However, Microsoft still supports NetBIOS names in Windows2000 to work with previous versions of the network operating system, microsoft supports NetBIOS names in two ways: <br> by default, all clients using Windows2000 support registering and parsing NetBIOS names using the WINS service of the client.

The Windows2000 Server continues to provide an efficient WINS server to manage NetBIOS names in the network. Define NetBIOS Name

The NetBIOS name contains 16 bytes. The first 15 bytes are specified by the user and are expressed as follows: <br> A single user or computer on the Network <br> A group of users or computers on the network

The 16th characters in the NetBIOS name are used as the name suffix to identify the name and display the Registration Name Information. NetBIOS names can be set to independent names or group names.

When an independent name is used, the network information is sent to a computer, and the group name is used to send the network information to multiple computers at the same time.

In earlier versions of WindowsNT, all network services were registered using NetBIOS names. In Windows, the login Network and other network services are
.

1.2 NetBIOS name resolution
The resolution of NetBIOS name is to map the NetBIOS Name of the computer to the IP address. As you can see above, the NetBIOS name is used to identify the address of NetBIOS resources on the network consisting of 16 characters. The following example shows how NetBIOS is resolved.

The process of parsing the NetBIOS names of files running on a Windows Server and printing shared services. When the computer starts, the file and print sharing service registers an independent NetBIOS name on the network using the computer name. The top 15 characters of NetBIOS name are computer names, with 16th characters 0x20. If the computer name is less than 15 characters long, use spaces to complete. (That is, corpserver [20]). When a user tries to establish a communication with the shared folder of the computer, he must specify the file and the NetBIOS name shared by the printer. Before establishing a file-print shared connection, you must first establish a TCP connection. To establish a TCP connection, you must first resolve the NetBIOS Name (namely, corpserver [20]) to an IP address. The wins client mainly uses the combination of broadcast, LmHosts file, and WINS server to solve the NetBIOS name resolution problem. It is divided into four netbiosnode modes based on different combinations, as shown in the following table:
Node Mode

Description
B-node users use the broadcast NetBIOS name query method to register and resolve the names. After the broadcast fails, query the LmHosts file and find the corresponding address.
P-node (peer-peer)
Query the IP address of the corresponding NetBIOS name directly from the WINS server in point-to-point mode. M-node (mixed)
M-node combines B-node and p-node. The broadcast method is used by default. If the broadcast fails, the query is performed on the WINS server. H-node (hybrid)
H-node combines B-node and p-node. Query is performed on the WINS server by default. If the query fails, broadcast is used. If both methods fail, query the LmHosts file and find the corresponding address. The computer running Windows uses the B-node mode by default. When the WINS server is set for them, the H-node mode is used. Windows2000 can also use the local database file LmHosts to parse NetBIOS names. This file is stored in the SYSTEMROOT/system32/Drivers/etc folder.

You must set a WINS Server IP address for Windows computers based on the Active Directory so that they can communicate with windows, windows, and Windows 98 computers that cannot use the Active Directory.

LmHosts Query

LmHosts queries are used for static resolution of NetBIOS names. Maps the NetBIOS Name and IP address. The function is similar to DNS, except that DNS maps the domain name/Host Name and IP address.

The LmHosts file is a plain text file. Microsoft provides the example program LmHosts. Sam, which is located in the C:/winnt/system32/Drivers/etc directory. If we need to enable LmHosts file query (as we will talk about when this resolution method will be used), we should change it to LmHosts, of course, the recommended method is to make a copy (save it as lmhosts), which saves the trouble of unhandled and correcting the original file and having to decompress and restore it from the installation disc. The following is part of The LmHosts file:
#
# The following example extends strates all of these extensions:
#
#102.54.94.97 rhino # pre # DOM: Networking # net group's DC
#102.54.94.102 "appname/0x14" # special app Server
#102.54.94.123 popular # pre # source server
#102.54.94.117 localsrv # pre # needed for the include
#
# Begin_alternate
# Include // localsrv/public/LmHosts
# Include // rhino/public/LmHosts
# End_alternate
#
# End of this file.

From the above example, we can see that the LmHosts file is in the same format as the hosts file we have already touched, and its rules are also the same, for example:
# The characters are used for comments;
The IP address must be placed in the first column of a line, and there must be spaces between the address and the host name;
The computer name can contain a maximum of 16 characters, but only 15 characters can be entered.

However, unlike hosts, The LmHosts file can specify specific commands for executing certain special functions. They are also marked with #, but if the following special string is displayed, it indicates that it is a command word:

# Pre -- this command is placed after the IP address and name, indicating that the address is preloaded to the cache (memory cache) when the system starts. During the query, the system starts from the cache. If the query fails, broadcast the query and then fail to read it in sequence in The LmHosts file.

# DOM: domain_name -- this command is placed after the computer's NetBIOS name, indicating that it is a domain controller. Here, domani_name is a domain name, indicating which domain the Controller belongs.

# Include -- this command adds another LmHosts file pointed to by filename to this file. The system reads the IP address and NetBIOS name from this file. Heatch remembers that he had encountered the same format when he had to take the grade test for C. there is a similar example [include] When sys is configured for multiple boot operations. Even if we use dreamwaver for Web pages, is there server-side include, to say so much, I just want to prove its benefits-centralized management of LmHosts files, that is, The LmHosts files shared by all users can be put on the server, each user adds the # include command to his LmHosts file.

# Begin_alternate and # end_alternate commands must be used together. They can be used to specify multiple # include commands in an LmHosts file, that is, if we have more than two domain controllers, then we can include the LmHosts file on it. Once a controller "Sacrifices", it can be replaced by another domain controller immediately.

/0xnn -- here the/0xnn command is used to specify NetBIOS names that contain non-printable characters in The LmHosts file, which must be enclosed in quotation marks. As previously mentioned in wins (2), these non-printable characters are only used for special device names, it can only be placed at the end of the computer name with 16th characters (my computer name is not as long as 15 characters-Press the Space key), for example, 102.54.94.102 "appname/0x14"

Special instructions on preload:
1. A maximum of 100 IP addresses and computer names can be preloaded in an LmHosts file;
2. # Add the # pre command to all items in the file to which the include command points;
3. Modify the Registry to increase the number of pre-loads: HKEY_LOCAL_MACHINE/system/CurrentControlSet/services/netbt/parameters, create a new string value maxpreloads, and enter the desired number.
The LmHosts file is not used in the network environment of the WINS server. The LmHosts file is introduced to solve the limitations that the broadcast method cannot cross the vro, the LmHosts file and the broadcast method are used together to implement full communication between internal and external network segments. Here, let's take a look at their working processes:
1. When the system starts, preload the address and machine name set to # pre In The LmHosts file to the memory;
2. When the client sends a query request, it first checks whether the target IP address already exists in the cache;
3. Do not say you have found yourself. If it is not found in the cache, the system uses the broadcast method to search again;
4. The LmHosts file must be used if the broadcast query is not found;
5. Find it. OK! Add it to the cache and save it;
How can I implement cross-origin operations on LmHosts files? Do you remember the first lecture three days ago? We have mentioned a # DOM: domain_name command. Assume that we have two domains: lanhome01 and lanhome02. Their IP addresses are 192.168.0.1 and 192.168.1.10, and their computer names are heatch01 and heatch02, respectively, currently, cxy01, a workstation in the lanhome01 domain, wants to log on to the lanhome02 domain, but we have not run the WINS service on the network. If you only use the broadcast method, cxy01 cannot be reviewed and authenticated by the lanhome02 domain controller. Here, you only need to add the following line to the LmHosts file:
192.168.1.10 heatch02 # pre # DOM: lanhome02

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