Configure TCP/IP networking while NetBIOS is turned off on a server running Windows Server 2003 - Windows Server (2024)

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This step-by-step article describes how to configure a computer running Windows Server 2003 with TCP/IP networking while NetBIOS is turned off.

Applies to: Windows Server 2003
Original KB number: 323357

Summary

On a computer running Windows Server 2003, you can turn off NetBIOS over TCP/IP (NetBT) for selected clients on an "as needed" basis. If you prefer to only use DNS to provide name registration and resolution on a specified computer that is used in a specialized or secured role for your network, you can turn off NetBT services for one or all of the network adapters that are installed on that computer.

Configuration

To turn off WINS/NetBT name resolution, follow these steps:

  1. Click Start, point to Settings, and then click Network Connections.
  2. Right-click the local area connection that you want to be statically configured, and then click Properties.
  3. Click Internet Protocol (TCP/IP) > Properties > Advanced, and then click the WINS tab.
  4. Click Disable NetBIOS over TCP/IP.

    Note

    Before you turn off WINS/NetBT name resolution, verify that you don't need to use WINS or earlier NetBT-type applications for this network connection. For example, you can turn off WINS/NetBT name resolution if you communicate only with other that run a product in Windows Server 2003 (Microsoft Windows XP, or Microsoft Windows 2000) that use DNS and that register their names with DNS, or if you communicate with Internet computers using DNS-aware applications. Do not turn off WINS/NetBT name resolution if you communicate with computers that run a version of Windows that may use WINS or earlier NetBT-type applications (such as Microsoft Windows NT, Microsoft Windows Millennium Edition, Microsoft Windows 98, or Microsoft Windows 95).

  5. Click OK > OK >OK.

    Note

    Optionally, you can select the Use NetBIOS setting from the Dynamic Host Configuration Protocol (DHCP) server if you use a DHCP server that can selectively turn on and turn off NetBIOS configurations through DHCP option types. When you use DHCP option types that are supported by the Windows Server 2003 DHCP Server service, you can turn off NetBIOS over TCP/IP for computers that run Windows Server 2003.

Troubleshooting

Computers That Run Windows Server 2003 Operating Systems

  • The computer no longer listens for traffic on the NetBIOS datagram service at User Datagram Protocol (UDP) port 138, the NetBIOS name service at UDP port 137, or the NetBIOS session service at Transmission Control Protocol (TCP) port 139.
  • If the computer needs to participate in WINS as a client, it must be physically multihomed (that is, it must have other physical network connections active and available for its use) for it to continue to communicate with and use a WINS server.

Computers That Operate as WINS Clients

  • The computer can no longer function as a WINS server to service WINS clients over the connection unless you turn NetBT on again.

  • For those adapters to use WINS, you must either manually configure a list of WINS servers on the NetBT connections that are turned on, or you must use a DHCP server to provide a list of WINS servers to these connections.

    Note

    WINS servers that are configured in TCP/IP properties for the network adapter that is turned off do not apply to other installed network adapters.

Down-Level Clients, Services, and Programs

  • NetBIOS defines a software interface and a naming convention. It doesn't define a protocol. NetBIOS over TCP/IP provides the NetBIOS programming interface over the TCP/IP protocol. It extends the reach of NetBIOS client and server programs to the wide area network (WAN). It also provides interoperability with various other operating systems.

  • The Workstation service, Server service, Browser service, Messenger service, and Net Logon service are all direct NetBT clients. They use Transport Driver Interface (TDI) to communicate with NetBT. Microsoft Windows NT, Windows 2000, and Windows Server 2003 also include NetBIOS emulators. The emulator takes standard NetBIOS requests from NetBIOS programs and translates them to equivalent TDI primitives.

  • Windows Server 2003 uses NetBIOS over TCP/IP to communicate with earlier versions of Windows NT and other clients, such as Microsoft Windows 95.

    You must do careful testing before you turn off NetBIOS over TCP/IP in any production environment. Programs and services that depend on NetBIOS no longer work after you turn off NetBT services, so it's important that you verify that your clients and programs no longer require NetBIOS support before you turn it off.

    Note

    Computers that run an operating system earlier than Windows 2000 will not be able to browse, locate, or create file and print share connections to a computer that runs a product in Windows Server 2003 with NetBIOS turned off.

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Configure TCP/IP networking while NetBIOS is turned off on a server running Windows Server 2003 - Windows Server (2024)

FAQs

What happens if you disable NetBIOS? ›

There are many security concerns with NetBIOS; and disabling its support on your network and devices is strongly recommended. Disabling the use and support of NetBIOS can help to mitigate an attacker's ability to: poison and spoof responses, obtain a user's hashed credentials, inspect web traffic, etc.

How to enable NetBIOS over TCP IP Windows Server? ›

  1. Click Start | Settings | Control Panel | Network.
  2. Double click the TCP/IP->adapter entry for the local area network.
  3. Click NetBIOS.
  4. The I want to enable NetBIOS over TCP/IP box is normally checked and grayed out. If it's un-checked, click the box to put in a check mark.

How to disable NetBIOS over TCP IP support? ›

Configuration
  1. Click Start, point to Settings, and then click Network Connections.
  2. Right-click the local area connection that you want to be statically configured, and then click Properties.
  3. Click Internet Protocol (TCP/IP) > Properties > Advanced, and then click the WINS tab.
  4. Click Disable NetBIOS over TCP/IP.
Dec 26, 2023

Should I disable NetBIOS over TCP IP on domain controller? ›

NetBIOS over TCP/IP is not required for standard Windows networking function. You'd only need it if you are using legacy applications that require that API to function. Disable it, if you must, and re-enable it if you have problems with your apps. It will not “hurt” to leave it enabled.

Does Windows still need NetBIOS? ›

NetBIOS is legacy and you only need it if you are using old applications or old versions of Windows that require it or use WINS. If your running applications or OS's that require it still, NetBIOS is probably not the real problem here.

Why is NetBIOS needed? ›

NetBIOS is an abbreviation of Network Basic Input/Output System. The primary purpose of NetBIOS is to allow applications on separate computers to communicate and establish sessions to access shared resources, such as files and printers, and to find each other over a local area network (LAN).

Why should you disable NetBIOS over TCP IP? ›

Enabling NetBios might help an attackers access shared directories, files and also gain sensitive information such as computer name, domain, or workgroup.

What does disable NetBIOS over TCP IP do? ›

It is also recommended to disable NetBIOS over TCP/IP to improve network performance. Disabling NetBIOS over TCP/IP is especially recommended on Hyper-V and Windows Server cluster hosts with dedicated NICs used for traffic, such as iSCSI and Live Migration.

How do I check if NetBIOS over TCP IP is enabled? ›

How to check if NetBIOS is enabled. Run the command ipconfig /all and check the NetBIOS over Tcpip value.

Is NetBIOS a security risk? ›

If NetBIOS is enabled and open to the outside, attackers may try to reach shared directories and files. This also gives sensitive information to the attacker such as the computer name, domain, or workgroup. Solution: The recommended solution is to block it in your firewall (or even your router, using ACLs).

What ports does NetBIOS use? ›

NetBIOS provides three distinct services:
  • Name service for name registration and resolution (ports: 137/udp and 137/tcp)
  • Datagram distribution service for connectionless communication (port: 138/udp)
  • Session service for connection-oriented communication (port: 139/tcp)

Is NetBIOS enabled by default? ›

NetBIOS services are enabled by default. If you want to disable NetBIOS services, set the value of the netbios_enable property to false .

What is the difference between NetBIOS and NetBIOS over TCP IP? ›

NetBIOS over TCP/IP (NBT) supports legacy applications that use the NetBIOS protocol as well as the NetBIOS name server (NBNS), which converts NetBIOS names into IP addresses. NetBIOS names are the names (up to 15-characters long) that users assign to their computers in a DOS/Windows network. See NetBIOS and TCP/IP.

Should NetBIOS be blocked? ›

Enabling NetBIOS services provide access to shared resources like files and printers not only to your network computers but also to anyone across the internet. Therefore it is advisable to block port 137 in the Firewall.

Does Active Directory still use NetBIOS? ›

The use of NetBIOS scopes in names is a legacy configuration. It shouldn't be used in Active Directory forests. This is not an inherent problem. However, some applications might filter the name and assume a DNS name if a period is found.

Why is NetBIOS on my Mac? ›

When making outbound connections to servers, SMB 1 and NetBIOS are enabled by default in macOS to improve compatibility with third-party products. macOS will attempt to use the later versions of SMB, as well as DNS and port 445, with failover to port 139 and SMB 1 as needed.

What services depend on NetBIOS? ›

NetBIOS provides three distinct services:
  • Name service for name registration and resolution (ports: 137/udp and 137/tcp)
  • Datagram distribution service for connectionless communication (port: 138/udp)
  • Session service for connection-oriented communication (port: 139/tcp)

Why is NetBIOS vulnerable? ›

The NetBIOS Name Server (NBNS) protocol does not perform authentication, which allows remote attackers to cause a denial of service by sending a spoofed Name Conflict or Name Release datagram, aka the "NetBIOS Name Server Protocol Spoofing" vulnerability.

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