A. Below is a list of the most common TCP ports.

Keyword Port Description
echo 7 Echo
systat 11 Active Users
qotd 17 Quote of the day
msp 18 Message Send Protocol
ftp-data 20 File Transfer (Data Channel)
ftp 21 File Transfer (Control)
telnet 23 Telnet
smtp 25 Simple Mail Transfer
name 42 TCP Nameserver
bootps 67 Bootstrap Protocol Servre
bootpc 68 Bootstrap Protocol Client
tftp 69 Trival File Transfer
gopher 70 Gopher
finger 79 Finger
www 80 World Wide Web
kerberos 88 Kerberos
pop3 110 TCP post office
nntp 119 USENET
nfs 2049 Network File System