Should You Disable NetBIOS?

Should NetBIOS be enabled?

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..

What is the purpose of NetBIOS?

NetBIOS (Network Basic Input/Output System) is a program that allows applications on different computers to communicate within a local area network (LAN). It was created by IBM for its early PC Network, was adopted by Microsoft, and has since become a de facto industry standard.

Is NetBIOS a security risk?

Vulnerabilities in Windows Host NetBIOS to Information Retrieval is a Low risk vulnerability that is also high frequency and high visibility. This is the most severe combination of security factors that exists and it is extremely important to find it on your network and fix it as soon as possible.

Should you disable NetBIOS over TCP IP?

A. Yes. To improve performance, it’s recommended that you disable NetBIOS over TCP/IP on your cluster network NIC and other dedicated-purpose NICs, such as for iSCSI and Live Migration. … To disable NetBIOS over TCP/IP, access the IPv4 properties of your network adapter.

What port is NetBIOS ns?

Port 137 DetailsPort(s)ProtocolService137tcp,udpnetbios-ns137tcp,udp137tcptrojan137udptrojan7 more rows

What is the difference between NetBEUI and NetBIOS?

The main difference between NetBIOS and NetBEUI is the fact that the latter formalizes the frame format that wasn’t indicated as part of the original NetBIOS (the frame format of course refers to how information is arranged in a given data delivery or transmission).

What are ports 137 and 138 used for?

Ports 137, 138, and 139 are used by NetBIOS, which does not support IPv6. CIFS is required for Windows file service. You can disable CIFS by issuing the cifs terminate command on your storage system console.

What are NetBIOS ports?

NetBIOS over TCP traditionally uses the following ports: nbname: 137/UDP. nbname: 137/TCP. nbdatagram: 138/UDP. nbsession: 139/TCP.

What is NetBIOS SSN?

Description. This indicates an attempt to use the NetBIOS-SSN protocol. NetBIOS Session Service (NBSS) is a protocol to connect two computers to transmit heavy data traffic. It is mostly used for printer and file services over a network.

Is NetBIOS obsolete?

Amazingly, NetBIOS is actually still used in the trust creation process, even though Microsoft has officially “deprecated” NetBIOS in versions of Windows from 2000 on. So if you disable NETBIOS on your domain controllers, you won’t be able to establish a forest trust between two Windows Server 2003 forests.

How do I block NetBIOS traffic?

To disable NetBIOS over TCP/IP, follow these steps:Got to Start | Control Panel, and double-click the System applet.On the Hardware tab, click the Device Manager button.Select Show Hidden Devices from the View menu.Expand Non-Plug And Play Drivers.Right-click NetBios Over Tcpip, and select Disable.More items…•Mar 12, 2008

Should I close port 139?

Port 139 is utilized by NetBIOS Session service. 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 139 in the Firewall.

Should I disable port 135?

Hacker tools such as “epdump” (Endpoint Dump) can immediately identify every DCOM-related server/service running on the user”s hosting computer and match them up with known exploits against those services. Therefore, port 135 should not be exposed to the internet and must be blocked.

What is the difference between NetBIOS and DNS?

As has been shown above the main difference between DNS and NetBIOS is the availability of DNS being only available when there is a connection to the internet and the name is registered in the computer. NetBIOS on the other hand is always available to the machines connecting directly to it.

Should I disable port 445?

We also recommend blocking port 445 on internal firewalls to segment your network – this will prevent internal spreading of the ransomware. Note that blocking TCP 445 will prevent file and printer sharing – if this is required for business, you may need to leave the port open on some internal firewalls.

How do I disable NetBIOS service?

Navigate to Administrative Tools > Services, right-click TCP/IP NETBIOS Helper, and click Stop. Right-click TCP/IP NETBIOS Helper, click Properties, and in the Startup type list, select Disabled. Click OK.

Which ports should I block?

For example, the SANS Institute recommends blocking outbound traffic that uses the following ports:MS RPC – TCP & UDP port 135.NetBIOS/IP – TCP & UDP ports 137-139.SMB/IP – TCP port 445.Trivial File Transfer Protocol (TFTP) – UDP port 69.Syslog – UDP port 514.More items…•Oct 16, 2015

What is NetBIOS attack?

NetBIOS attack is a hacking type that exploits a bug in Windows. They don’t require you to have any hidden backdoor program running on your computer. This make NetBIOS the worst attack. NetBIOS is meant to be used on local area networks, so machines on that network can share information.

Why is NetBIOS bad?

There are quite a few reasons why NetBIOS is bad for your network. NetBIOS is an inneficient protocol. It is very chatty with lots of broadcasts. When used with its defaults settings, it can be used by the bad guys to gather information about your network and users.

Is NetBIOS needed for SMB?

SMB does rely on NetBIOS for communication with devices that do not support direct hosting of SMB over TCP/IP. NetBIOS is completely independent from SMB. It is an API that SMB, and other technologies can use, so NetBIOS has no dependency to SMB.

What is NetBIOS setting?

NetBIOS over TCP/IP (NBT, or sometimes NetBT) is a networking protocol that allows legacy computer applications relying on the NetBIOS API to be used on modern TCP/IP networks.