Does SMB use NetBIOS or DNS?

The default is NetBIOS. Many SMB clients have configuration options to enable NetBIOS over TCP/IP, SMB directly over TCP/IP, or both.

Is NetBIOS required for SMB?

On Windows, SMB can run directly over TCP/IP without the need for NetBIOS over TCP/IP. This will use, as you point out, port 445 . Generally speaking, on other systems, you'll find services and applications using port 139 .

Does SMB use DNS?

To use the shares that the SMB server makes available, PC clients must be able to find the server on the network. The communications mechanism used is TCP/IP and the methods of server discovery follow: The Domain Name Service (DNS)

What is SMB over NetBIOS?

As such, SMB requires network ports on a computer or server to enable communication to other systems. SMB uses either IP port 139 or 445. Port 139: SMB originally ran on top of NetBIOS using port 139. NetBIOS is an older transport layer that allows Windows computers to talk to each other on the same network.

What protocol does SMB use?

Now, SMB runs directly over TCP/IP and uses port 445. Today, communications with devices that do not support SMB directly over TCP/IP require the use of NetBIOS over a transport protocol such as TCP/IP. Microsoft Windows operating systems (OSes) since Windows 95 have included client and server SMB protocol support.

NetBIOS And SMB Enumeration - Nbtstat

Why is NetBIOS still used?

NetBIOS (Network Basic Input/Output System) was created in the early 1980's, but is surprisingly still alive and well on many networks today. Microsoft Windows still uses it for its name resolution function (often by default), when DNS is not available.

What is NetBIOS used for?

NetBIOS (Network Basic Input/Output System) is a network service that enables applications on different computers to communicate with each other across a local area network (LAN). It was developed in the 1980s for use on early, IBM-developed PC networks.

Does SMB use TCP?

SMB relies on the TCP and IP protocols for transport. This combination potentially allows file sharing over complex, interconnected networks, including the public Internet. The SMB server component uses TCP port 445.

Does SMB work over Internet?

Port 139 is used by SMB dialects that communicate over NetBIOS. It's a transport layer protocol designed to use in Windows operating systems over a network. Port 445 is used by newer versions of SMB (after Windows 2000) on top of a TCP stack, allowing SMB to communicate over the Internet.

Is SMB routable?

It depends on some aspects of the protocols and implementations. NetBIOS/NetBEUI is not routable at all and it works sending broadcasts. Workgroups, domain joining, browsing, hostname update and other features of the SMB suite will be restricted to your network due those limitations.

What are NetBIOS names?

NetBIOS Name is a 16-byte name for a networking service or function on a machine running Microsoft Windows Server. NetBIOS names are a more friendly way of identifying computers on a network than network numbers and are used by NetBIOS-enabled services and applications.

How do you check if SMB signing is enabled?

From the Start menu, search for msc. Set Microsoft network client to “Enabled” for “Digitally sign communications (always)” and the Microsoft network server “Digitally sign communications (always).” If on a local system, reboot the computer and use Nmap to validate that SMB2 signing is required.

What is Alias DNS?

An ALIAS record is a type of DNS record that points your domain name to a hostname instead of an IP address. Important.

Does SMB uses TCP or UDP?

Windows supports file and printer-sharing traffic by using the SMB protocol directly hosted on TCP. SMB 1.0 and older CIFS traffic supported the NetBIOS over TCP (NBT) protocol supported the UDP transport, but starting in Windows Vista and Windows Server 2008 with SMB 2.0. 2, requires TCP/IP over port 445.

Is NetBIOS over TCP IP required?

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. NetBIOS isn't used in Server 2008 R2 clusters.

Does Active Directory use NetBIOS?

A computer running Windows in an Active Directory domain has both a DNS domain name and a NetBIOS domain name, as follows: DNS domain name: The DNS domain name consists of one or more subdomains separated by a dot (.)

What OSI layer does SMB operate on?

In the OSI networking model, Microsoft SMB Protocol is most often used as an Application layer or a Presentation layer protocol, and it relies on lower-level protocols for transport. The transport layer protocol that Microsoft SMB Protocol is most often used with is NetBIOS over TCP/IP (NBT).

Is NetBIOS UDP or TCP?

The protocols in the NetBIOS over TCP/IP suite implements the NetBIOS services atop TCP and UDP, which is described in RFC 1001 and RFC 1002. NetBIOS over TCP/IP (also called NBT) seems to slowly supersede all the other NetBIOS variants.

What is SMB domain?

A variable length structure that uniquely identifies a user or group both within the local domain and across all possible Windows domains. Server Message Block (SMB) A protocol that enables clients to access files and to request services of a server on the network. share.

Does CIFS need NetBIOS?

Implementation of the NetBIOS API is not required for CIFS.

What is the difference between NetBIOS and DNS?

What is this? 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.

How do you determine if NetBIOS is being used?

Both your Active Directory domain FQDN and NetBIOS can be confirmed using simple command prompt commands. Type nbtstat -n and it will display some information. Under Name will be several entries: the NetBIOS will be one of the Group type.

What has replaced NetBIOS?

Today, DNS has replaced WINS, since Microsoft made changes to NetBIOS, allowing it to use the TCP/IP stack to perform its job (NetBIOS over TCP/IP) and most DNS servers are able to handle NetBIOS requests.

Is NetBIOS deprecated?

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.

What is the difference between SMB and CIFS?

CIFS (Common Internet File System) and SMB (Server Message Block) are both Windows file-sharing protocols used in storage systems, such as network-attached systems (NAS). The key difference between CIFS and SMB is that CIFS is a dialect of SMB – a particular implementation of the SMB protocol.