TCP 20
TCP port 20 protocol information and warnings.
Looking for information on Protocol TCP 20? This page will attempt to provide you with as much port information as possible on TCP Port 20.
TCP Port 20 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.
TCP Port 20
Here is what we know about protocol TCP Port 20. If we do not have any information on port 20 in our database, a counter will be set for TCP port 20. After enough hits, we'll research this port and update the database.
If you have information on TCP port 20 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 20 will have the most accurate information.
PORT 20 - Information
| Port Number: | 20 |
| TCP / UDP: | TCP |
| Delivery: | Yes |
| Protocol / Name: | ftp-data |
| Port Description: | This is the FTP service's default data transfer port; required inbound if internal users are allowed access to external FTP sites, yet open port poses a threat (hole for network mapping, etc). Modern firewalls solve this by keeping it closed until a valid FTP session exists, then only opening it between those hosts. Control via a stateful-tracking firewall, do not simply open at perimeter. |
| Virus / Trojan: | No |
Side note: TCP port 20 uses the Transmission Control Protocol. TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered on port 20 in the same order in which they were sent. Guaranteed communication over port 20 is the key difference between TCP and UDP. UDP port 20 would not have guaranteed communication in the same way as TCP.
TCP 20 - Disclaimer
We do our best to provide you with accurate information on PORT 20 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!