Nmap tool provides a popular ports list as a database where this list is also used in network and service scans. Here is the list but before we will look at the command which will list ports according to the popularity.
Nmap Top Ports Listing
We can use sort command in order to list ports according to their usage frequency. The Nmap port or service database located at /usr/share/nmap/nmap-services . We provide -k3 which specifies the column number of the frequency.
$ sort -r -k3 /usr/share/nmap/nmap-services
Top 10 Port List
We will list and explain most popular ports in this part.
FTP
- File Transfer Protocol or simply FTP is old protocol which is designed to file transfer over network.
- TCP 20 and TCP 21
SSH
- Secure Shell protocol which is designed to connect and get a secure encrypted shell to the remote host. It is popular in Linux ecosystem.
- TCP 22
TELNET
- Clear text or unsecure remote shell protocol which is older than SSH. Telnet mainly used by network devices and printers
- TCP 23
SMTP
- Simple Mail Transfer Protocol is used to trans mail data between servers. It is defacto standard for mail delivery.
- TCP 25
DNS
- Domain Name System is used to resolve domain names to IP address or reverse way.
- TCP 53 and UDP 53
DHCP
- Dynamic Host Control Protocol is used to provide host configuration over network which is mainly used to set IP address to the hosts.
- UDP 67 and UDP 68
TFTP
- Trivial File Transfer Protocol is more basic version of the FTP and it has no security mechanism.
- UDP 69
HTTP
- Hyper Text Transfer Protocol is the most of the todays internet. It is used to server web pages over web servers.
- TCP 80
HTTPS
- HTTPS is the secure version of the HTTP protocol
- TCP 443
NTP
- Network Time Protocol is used to change date and time information over network
- UDP 123
SNMP
- Simple Network Management Protocol is developed to manage devices over the network but mainly used to monitor devices in today.
- TCP 161, 162 and UDP 161,162