UDP on port 137 is Windows NetBIOS Name Service, typically Windows file sharing (on a LAN).. passing System Names, File Shares, etc. Unexplained outbounds on UDP 137, in volume, might indicate a possible worm infection (trying to seek other victims). This being a possibility, you should update your AV definitions & run a scan.
Ports 137-139 | Wilders Security Forums Jun 05, 2006 Security Basics: Re: Listener on ports 137, 138, 139 Port 137 is Netbios NAME, 138 is Netbios DATAGRAM, and 139 is Netbios SESSION, and none of them are anything to be worried about (Except, read below) Netbios is mostly used for local area networks and works independent to your ADSL (Though netbios can work over wide area networks as well). How To Open Firewall Ports In Windows 10 | Tom's Hardware Open firewall ports in Windows 10 You can manually permit a program to access the internet by opening a firewall port. You will need to know what port it uses and the protocol to make this work. How to disable Ports 135, 137-139, 445 (Windows XP)
Dec 01, 2012 · UDP port 137 should not connect to a external address normally. The port is used by NETBios. Which is used for File and Printer Sharing, and Domain server traffic. Check your firewall rules. Normally this should not be allowed, unless someone made a firewall rule that explicitly allows this. I am not familiar with remote access tools.
System.exe and Port 137 - Anti-Virus, Anti-Malware, and Apr 02, 2009 Using telnet to Test Open Ports | The Complete How-To
How To Open Firewall Ports In Windows 10 | Tom's Hardware
Mar 29, 2020 · 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. Port 445: Later versions of SMB (after Windows 2000) began to use port 445 on top of a TCP stack. Using TCP allows SMB to work over the Dec 09, 2013 · To transfer initial data and schema from one location to another, replication can use FTP (TCP port 21), or sync over HTTP (TCP port 80) or File Sharing. File sharing uses UDP port 137 and 138, and TCP port 139 if it using NetBIOS. Beginning with Windows 2003, File Sharing uses TCP port 445. Mar 10, 2020 · Applies to: Windows Server version 1909 Windows Server version 1903 Windows Server 2019 Windows 10, version 1809, all editions Windows Server version 1803 Windows 10, version 1803, all editions Windows 10, version 1709, all editions Windows 10, version 1703, all editions Windows Server 2016 Windows 10, version 1607, all editions Windows 10 Windows Server 2012 R2 Datacenter Windows Server 2012 May 15, 2019 · If the client is an older version of Windows, like Windows 2000, and has NBT enabled, it will always try to connect to the server at both port 139 and 445 simultaneously. If there is a response from port 445, it sends a TCP RST (reset) to port 139, and continues its SMB session to port 445 only. May 31, 2018 · Opening an outgoing port. In the case that your application needs a specific outbound port to be opened, you can use the same instructions, but instead of selecting Inbound Rules on step No. 4, you would choose the Outbound Rules options, and then follow the same steps. Open Windows Defender Security Center. Click on Firewall & network protection. Apr 28, 2020 · Windows NT 4.0 tries to resolve manually-typed names by contacting the PDC for the remote user's domain (UDP 138). If that communication fails, a Windows NT 4.0-based computer contacts its own PDC, and then asks for resolution of the name. Windows 2000 and Windows Server 2003 also try to contact the remote user's PDC for resolution over UDP 138. The Windows 2000 implementation of NetBIOS over TCP/IP is referred to as NetBT. NetBT uses the following TCP and UDP ports: UDP port 137 (name services) UDP port 138 (datagram services) TCP port 139 (session services) NetBIOS over TCP/IP is specified by RFC 1001 and RFC 1002.