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 is port 445 commonly used for?

Port 445 is a traditional Microsoft networking port with tie-ins to the original NetBIOS service found in earlier versions of Windows OSes. Today, port 445 is used by Microsoft Directory Services for Active Directory (AD) and for the Server Message Block (SMB) protocol over TCP/IP.

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 is port 445 used for in Windows 10?

For direct TCP/IP MS networking connectivity, Microsoft Windows 10 uses port 445. It does not necessitate the use of the NetBIOS layer. Port 445 is associated with SMB (Service Message Block), an application layer network protocol that is mostly used for file sharing, printer sharing, and serial port sharing.

What happens when port 139 opens?

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.

What is an SMB Port? What is Port 445 and Port 139 used for?

What is the difference between port 139 and 445?

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.

Should I open 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.

Is port 139 needed for SMB?

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 happens if I block port 445?

Blocking TCP 445 will prevent file and printer sharing and also other services such as DHCP (dynamic host configuration protocol) which is frequently used for automatically obtaining an IP address from the DHCP servers used by many corporations and ISPs(Internet Service Providers) will stop functioning.

How do I close port 139?

How do I know if my port 445 is open?

Know if Your Port 445 is Enabled or Not

Then type: “netstat –na” and press Enter. “netstat –na” command means scan all connected port and showing in numbers. In one or two seconds, the picture will show up. Roll your mouse to the top and you'll see the IP address of 445.

How do I enable port 445?

Go to Computer Configuration > Policies > Windows Settings > Security Settings > Windows Firewall with Advanced Security > Windows Firewall with Advanced Security - LDAP > Inbound Rules. Right-click and choose New Rule. Choose Port and click Next. Choose TCP and at specific local ports enter 135, 445, then click Next.

What is the port 443 used for?

Port 443 is a virtual port that computers use to divert network traffic. Billions of people across the globe use it every single day. Any web search you make, your computer connects with a server that hosts that information and fetches it for you. This connection is made via a port – either HTTPS or HTTP port.

Does port 445 use TCP or UDP?

Port 445 Details. TCP port 445 is used for direct TCP/IP MS Networking access without the need for a NetBIOS layer. The SMB (Server Message Block) protocol is used for file sharing in Windows NT/2K/XP and later. In Windows NT it ran on top of NetBT (NetBIOS over TCP/IP, ports 137, 139 and 138/udp).

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.

Why do ISPS block 445?

But do you know where lots of ports are being blocked? Comcast, which is Blue Stream's upstream bandwidth provider. Comcast presumably blocks port 445 because it is used by the WannaCry malware to spread between systems. However, it's also the port Microsoft Active Directory uses.

What ports did WannaCry use?

The malware, known as 'WannaCry' has the capability to scan port TCP 445 (Server Message Block/SMB) spreading like a worm by exploiting CVE-2017-0147 (MS17-010) using the ETERNALBLUE modules and the DOUBLEPULSAR backdoor brought to the public by The Shadow Brokers group last April.

What ports does ransomware use?

This connection is known as call home or C2 traffic and normally uses the standard port 80 and HTTP or port 443 and HTTPS protocols. The information sent is usually operating system details, IP addresses, geographical location and access permissions of the account that executed the ransomware.

What SMB means?

SMB also stands for "Server Message Block" in the Server Message Block Protocol.

Is SMB secure over Internet?

1. SMB 2.0 or SMB 1.0 connections are not encrypted. Does the latest version of Windows 10 LTSC contain any unpatched vulnerabilities that would allow privilege escalation? Not a single person in the world could answer this question but if we're talking about publicly available data, then the answer will be "no".

What are the basic 3 types of firewalls?

According to their structure, there are three types of firewalls – software firewalls, hardware firewalls, or both.

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 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.