UDP 138
UDP port 138 protocol information and warnings.
Looking for information on Protocol UDP 138? This page will attempt to provide you with as much port information as possible on UDP Port 138.
UDP Port 138 may use a defined protocol to communicate depending on the application. A protocol is a set of formalized rules that explains how data is communicated over a network. Think of it as the language spoken between computers to help them communicate more efficiently.
Protocol HTTP for example defines the format for communication between internet browsers and web sites. Another example is the IMAP protocol that defines the communication between IMAP email servers and clients or finally, the SSL protocol which states the format to use for encrypted communications.
UDP Port 138
Here is what we know about protocol UDP Port 138. If we do not have any information on port 138 in our database, a counter will be set for UDP port 138. After enough hits, we'll research this port and update the database.
If you have information on UDP port 138 that is not reflected in our database, please leave a comment or post your information on our Web Security Forum. We'll update our database so that the next user searching for port 138 will have the most accurate information.
PORT 138 - Information
| Port Number: | 138 |
| TCP / UDP: | UDP |
| Delivery: | No |
| Protocol / Name: | netbios-dgm |
| Port Description: | NETBIOS Datagram Service. A principle rqmt for NetBIOS services on MS hosts (Win9x/ME/NT/Win2000). UDP 137 is used for browsing, directory replication, logon sequence, netlogon, pass-thru validation, printing support, trusts, and WinNT Secure Channel. Security Concerns: Key target in auth & DOS attacks. Block at all perimeters; NIC-filter on public-exposed MS hosts |
| Virus / Trojan: | No |
Side note: UDP port 138 uses the Datagram Protocol, a communications protocol for the Internet network layer, transport layer, and session layer. This protocol when used over PORT 138 makes possible the transmission of a datagram message from one computer to an application running in another computer. Like TCP (Transmission Control Protocol), UDP is used with IP (the Internet Protocol) but unlike TCP on Port 138, UDP Port 138 is connectionless and does not guarantee reliable communication; it's up to the application that received the message on Port 138 to process any errors and verify correct delivery.
UDP 138 - Disclaimer
We do our best to provide you with accurate information on PORT 138 and work hard to keep our database up to date. This is a free service and accuracy is not guaranteed. We do our best to correct any errors and welcome feedback!