What are ports 137 and 138 used for?

Microsoft Windows Networking Services

Port 135 is used for RPC client-server communication, and ports 139 and 445 are used for authentication and file sharing. UDP ports 137 and 138 are used for local NetBIOS browser, naming, and lookup functions.

What is the use of port 137?

Port 137 is utilized by NetBIOS Name 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 137 in the Firewall.

Is port 139 still needed for SMB?

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 is port 139 commonly used for?

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.

What happens when port 139 opens?

Firewalls, as a measure of safety always block this port first, if you have it opened. Port 139 is used for File and Printer Sharing but happens to be the single most dangerous Port on the Internet. This is so because it leaves the hard disk of a user exposed to hackers.

What is NetBIOS? Does Windows need its ports 137 and 138 open? (2 Solutions!!)

What application uses port 138?

Port 138 is utilized by NetBIOS Datagram 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.

What is port 135 commonly used for?

Port 135 is used for RPC client-server communication; ports 139 and 445 are used for authentication and file sharing. UDP ports 137 and 138 are used for local NetBIOS browser, naming, and lookup functions.

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 port does DHCP use?

DHCP is a network protocol to used to configure IP networks. A DHCP server listens to UDP port 67 and dynamically assigns IP addresses and other network parameters to DHCP clients. These clients will listen for responses on UDP port 68.

Should I open port 139?

If you are on Windows-based network that is running NetBios, it is perfectly normal to have port 139 open in order to facilitate that protocol. If you are not on a network using NetBios, there is no reason to have that port open.

Which port is used for telnet?

The default port for Telnet client connections is 23; to change this default, enter a port number between 1024 and 32,767.

What are ports 139 and 445 used for?

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.

What port does ping use?

What Port Does Ping Use? Remember that a ping test uses ICMP, so there are no real ports being used. ICMP basically roofs, or sits on top of, the IP address. Therefore it is not a layer four protocol.

Is it safe to have port 135 open?

It is a sensitive port that is associated with a slew of security vulnerabilities and should never be exposed to the internet. However, Port 135 is needed in an active directory and server/client environment for many services to operate properly.

How do I know if my TCP port 135 is open?

Using 'netstat -ab' to Identify Open Ports

Now, type “ netstat -ab ” without quotes, then press “Enter.” Wait for the results to load. Port names get listed next to each local IP address. Look for the port number you need, and if it says LISTENING in the State column, it means your port is “open.”

Should I disable port 135?

Disabling TCP port 135 will NOT affect Local DCOM/Raw RPC server component because they do not need network. Disabling TCP port 135 will only affect some client machine which directly use DCOM remote activation (i.e. VB CreateObject("Excel.

What port does domain controller use?

Both UDP and TCP Port 135 are required for communication between domain controllers and clients to domain controllers.

What is NetBIOS SSN service?

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.

How do I disable NetBIOS?

Step 1: Open control panel Step 2: Navigate to programs and features. Step 3: Click on "Turn Windows features on or off. Step 4: Disable "NetBios over TCP/IP"Step 5 : Click ok.

How do I block port 139?