| Name: | netbios-ns |
|---|---|
| Purpose: | NetBIOS Name Service |
| Description: | UDP NetBIOS name query packets are sent to this port, usually of Windows machines but also of any other system running Samba (SMB), to ask the receiving machine to disclose and return its current set of NetBIOS names. |
| Related Ports: | 138, 139, 445 |
Should I open 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.
What are the NetBIOS ports?
NetBIOS over TCP traditionally uses the following ports:
- nbname: 137/UDP.
- nbname: 137/TCP.
- nbdatagram: 138/UDP.
- nbsession: 139/TCP.
Is NetBIOS secure?
Vulnerabilities in Windows Host NetBIOS to Information Retrieval is a Low risk vulnerability that is one of the most frequently found on networks around the world. This issue has been around since at least 1990 but has proven either difficult to detect, difficult to resolve or prone to being overlooked entirely.
Should I disable NetBIOS?
There are many security concerns with NetBIOS; and disabling its support on your network and devices is strongly recommended. Disabling the use and support of NetBIOS can help to mitigate an attacker’s ability to: poison and spoof responses, obtain a user’s hashed credentials, inspect web traffic, etc.
What does NetBIOS _ DGM mean in datagram?
NETBIOS_DGM = Datagram Service udp port 138. NETBIOS_NS = Name Service udp port 137. Ports 135 – 139 & 445 are used for file & printer sharing, MS logons, and other good stuff.
Which is the most important service of NetBIOS?
NetBIOS provides three distinct services: Name service (NetBIOS-NS) for name registration and resolution. Datagram distribution service (NetBIOS-DGM) for connectionless communication. Session service (NetBIOS-SSN) for connection-oriented communication.
Is the NetBIOS name resolution supported by Microsoft?
NetBIOS name resolution is not supported by Microsoft for Internet Protocol Version 6 (IPv6) . Datagram mode is connectionless; the application is responsible for error detection and recovery. In NBT, the datagram service runs on UDP port 138. The datagram service primitives offered by NetBIOS are:
Which is UDP port does NetBIOS listen on?
NetBIOS also supports connectionless communications via UDP. Applications listen on UDP port 138 to receive NetBIOS datagrams. The datagram service can send and receive datagrams and broadcast datagrams. Following are some of the options the name service is allowed to send via NetBIOS: The session services allow these primitives:
