What Port Does SMB Use?

Is port 139 required for SMB?

What Are Ports 139 And 445.

SMB has always been a network file sharing protocol.

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..

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.

Is port 445 open by default?

If the server has NBT enabled, it listens on UDP ports 137 and 138, and TCP ports 139 and 445. … All four ports are open as default in all versions of Windows, including Windows 10 and Windows Server 2019.

What is the purpose of port 443?

Port 443 is used explicitly for HTTPS services and hence is the standard port for HTTPS (encrypted) traffic. It is also called HTTPS port 443, so all the secured transactions are made using port 443.

Should I block port 139?

Inbound connection in port 139 (TCP) is not blocked in Windows firewall. Port 139 is utilized by NetBIOS Session service. … Therefore it is advisable to block port 139 in the Firewall.

What does SMB mean?

small and medium-sized businessSMB is an abbreviation for small and medium-sized business, sometimes seen as small and midsized business. A business with 100 or fewer employees is generally considered small, while one with 100-999 employees is considered to be medium-sized.

Does SMB use TCP or UDP?

Direct hosted NetBIOS-less SMB traffic uses port 445 (TCP and UDP). In this situation, a four-byte header precedes the SMB traffic.

What is the use of port 445?

TCP port 445 is used for direct TCP/IP MS Networking access without the need for a NetBIOS layer. This service is only implemented in the more recent verions Windows starting with Windows 2000 and Windows XP. The SMB (Server Message Block) protocol is used among other things for file sharing in Windows NT/2K/XP.

What SMB version does Windows 10 use?

SMB 3.1 is supported on Windows clients since Windows 10 and Windows Server 2016, it is by default enabled. For information on how to enable or disable SMB2. 0/2.1/3.0, refer to the documentation of the relevant ONTAP version or contact NetApp Support.

What is SMB used for?

Stands for “Server Message Block.” SMB is a network protocol used by Windows-based computers that allows systems within the same network to share files. It allows computers connected to the same network or domain to access files from other local computers as easily as if they were on the computer’s local hard drive.

Is 445 TCP or UDP?

Port 445 DetailsPort(s)ProtocolService445tcpmicrosoft-ds445tcp445udp445tcptrojan35 more rows

How do I check if port 139 is open?

For test the port 139, please try use the IP address of the server, NetBIOS or FQDN. You can use the telnet command or PortQuery tools.

Is SMB port 445 secure?

blocking all versions of SMB at the network boundary by blocking TCP port 445 with related protocols on UDP ports 137-138 and TCP port 139, for all boundary devices. …

Which SMB version should I use?

The version of SMB used between two computers will be the highest dialect supported by both. This means if a Windows 8 machine is talking to a Windows 8 or Windows Server 2012 machine, it will use SMB 3.0. If a Windows 10 machine is talking to Windows Server 2008 R2, then the highest common level is SMB 2.1.

Is SMB secure?

The support article defined SMB as “a network file sharing and data fabric protocol” that’s used by various operating systems, “including Windows, MacOS, iOS, Linux and Android.” This SMB traffic can be protected at the firewall level, though.

What is the protocol for port 138?

Port 138 DetailsPort(s)ProtocolService138tcptrojan138tcpChode138udpthreat138tcp,udpnetbios-dgm2 more rows

What ports are used for Windows file sharing?

Microsoft file sharing SMB: User Datagram Protocol (UDP) ports from 135 through 139 and Transmission Control Protocol (TCP) ports from 135 through 139. Direct-hosted SMB traffic without a network basic input/output system (NetBIOS): port 445 (TCP and UPD).

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.