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outbound port 137 from my computer to websites
TeamViewer remote desktop protocol []. Considering all the security reasons described above, many ISPs feel it necessary to block this Port on behalf of their users. Archived from the original on Tell us about your experience with our site. Enterprise configuration repository server []. QBittorrent 's embedded torrent tracker default port []. Or does my Windows need them open for some purpose?

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Ports 137-139

In order to start sessions or distribute datagrams, an application must register its NetBIOS name using the name service. NetBIOS names are 16 octets in length and vary based on the particular implementation.

Frequently, the 16th octet, called the NetBIOS Suffix, designates the type of resource, and can be used to tell other applications what type of services the system offers. Datagram mode is connectionless ; the application is responsible for error detection and recovery.

Session mode lets two computers establish a connection, allows messages to span multiple packets, and provides error detection and recovery. In the original protocol used to implement NetworkBIOS services on PC-Network, to establish a session, the initiating computer sends an Open request which is answered by an Open acknowledgment.

The computer that started the session will then send a Session Request packet which will prompt either a Session Accept or Session Reject packet. During an established session, each transmitted packet is answered by either a positive-acknowledgment ACK or negative-acknowledgment NAK response. A NAK will prompt retransmission of the data. Sessions are closed by the non-initiating computer by sending a close request. The computer that started the session will reply with a close response which prompts the final session closed packet.

A computer's NetBIOS name is often the same as that computer's host name see below , although truncated to 15 characters, but it may also be completely different. NetBIOS names are a sequence of alphanumeric characters.

Now that wouldn't really make me curious if it weren't for the fact that it is even sending these requests to websites that I browse, and that I really don't understand. Can anyone here explain why it would be doing this?

If you are just running a simple network at home, its best that you disable netbios completely since you most likely aren't using it. If netbios is enabled, other computers can use it to hack your machine. It's really not that simple. I have turned off "File and Print Sharing" in my network properties. NetBIOS itself is not evil. Still, I would like to know why my computer is sending outbound traffic to port when all I am doing is browsing a website.

You have three options: At home I have it blocked with a software firewall and an ACL on the router. I'd rather not get into a discussion about the good or evil of NetBIOS, or how to disable it, in this thread.

What I would like to understand is why browsing websites is causing my system to send UDP packets on port to the websites I am browsing. Because that's the way it is? BartSilverstrim I wish I could make a comment an answer: PS - do you know how I can enumerate everything listening on the directory port I think ?

Does netstat tell you what you're looking for on Windows? All the ports used by RPC are as follows: You can define a custom port range if you wish, like so: IP address resolved to host TCP port epmap service: Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name.

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The Windows implementation of NetBIOS over TCP/IP is referred to as NetBT. NetBT uses the following TCP and UDP ports: UDP port (name services) UDP port (datagram services) TCP port (session services) NetBIOS over TCP/IP is specified by RFC and RFC Jul 09,  · UDP is used by NetBIOS File sharing in Windows 7. Depending on what you do while you are using Remote Desktop on your network, it might invoke the UDP If it does not impede anything functional that you need to do, leave it alone. Can someone explain when and how often each of the Windows RPC ports are used? The "core" ones I understand are: Port Port Port Higher ports that are published by Port 's "catalog".