Is port 137 UDP or TCP?

Inbound connection in port 137 (UDP) is not blocked in Windows firewall. 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.

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.

What are ports 137 and 139 used for?

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.

What is TCP 135 port?

TCP port 135 is the Remote Procedure Call (RPC) Endpoint Mapper service. It enables other systems to identify what services are available on a machine and on which port they can be found. Essentially it allows a system unfettered access to a target system.

TCP vs UDP Comparison

What is NetBIOS UDP?

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.

Is SMB port 139 TCP or UDP?

The earlier version of SMB (SMB 1.0) was originally designed to operate on NetBIOS over TCP/IP (NBT), which uses port TCP 139 for session services, port TCP/UDP 137 for name services, and port UDP 138 for datagram services.

Is SMB UDP or TCP?

SMB relies on the TCP and IP protocols for transport. This combination potentially allows file sharing over complex, interconnected networks, including the public Internet. The SMB server component uses TCP port 445.

What type of traffic is normally seen over UDP port 137?

Protocol dependencies

UDP: Typically, NBNS uses UDP as its transport protocol. The well known UDP port for NBNS traffic is 137. TCP: NBNS can also use TCP as its transport protocol for some operations, although this might never be done in practice. The well known TCP port for NBNS traffic is 137.

What protocol does NetBIOS use?

In modern networks, NetBIOS normally runs over TCP/IP via the NetBIOS over TCP/IP (NBT) protocol. This results in each computer in the network having both an IP address and a NetBIOS name corresponding to a (possibly different) host name. NetBIOS is also used for identifying system names in TCP/IP (Windows).

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.

Does SMB need UDP?

Windows supports file and printer-sharing traffic by using the SMB protocol directly hosted on TCP. SMB 1.0 and older CIFS traffic supported the NetBIOS over TCP (NBT) protocol supported the UDP transport, but starting in Windows Vista and Windows Server 2008 with SMB 2.0. 2, requires TCP/IP over port 445.

Is port 445 TCP or UDP?

TCP port 445 is used for direct TCP/IP MS Networking access without the need for a NetBIOS layer. This service is only implemented in the more recent verions Windows starting with Windows 2000 and Windows XP. The SMB (Server Message Block) protocol is used among other things for file sharing in Windows NT/2K/XP.

What port is TCP 139?

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.

Do I need NetBIOS over Tcpip enabled?

A. Yes. To improve performance, it's recommended that you disable NetBIOS over TCP/IP on your cluster network NIC and other dedicated-purpose NICs, such as for iSCSI and Live Migration. NetBIOS isn't used in Server 2008 R2 clusters.

Is port 80 A TCP?

However, Port 80 provides an HTTP connection under TCP protocol. This port provides an unencrypted connection between the web browser and the web servers, which leaves the sensitive user data exposed to cybercriminals and may lead to severe data misuse.

Is UDP an IP?

TCP and UDP are part of the TCP/IP protocol suite, which includes a number of protocols for carrying out network communications.

What is network port 135 used for?

Microsoft Windows Networking Services

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.

Should TCP 135 be 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.