Perkify - Network Services
Written by Rich Morin.
Precis: introduction to Perkify's network services
Ubuntu is capable of providing a large number of network services, including common ones such as Hypertext Transfer Protocol (HTTP) and Secure Shell (SSH). Perkify starts with the default set and then sets up a few more. This page provides a summary of the provided services and associated ports.
The port number field contains 16 bits, allowing a range of port numbers from 0-65535. However, use of these numbers is subject to assorted constraints:
The port numbers are divided into three ranges: the well-known ports, the registered ports, and the dynamic or private ports.
The well-known ports (also known as system ports) are those from 0 through 1023. The requirements for new assignments in this range are stricter than for other registrations …
When a service is running on a virtual machine (VM), it has to avoid the ports that are being used by the host machine. The VM accomplishes this by using port forwarding. This maps some of the VM’s internal ports (e.g., 22) onto available dynamic ports (e.g., 2222) on the host machine.
The following table indicates which host ports the Perkify VM uses.
|Host Port||VM Port||Protocol Name||Typical Usage|
|8080||80||HTTP (Hypertext Transfer Protocol)||web server|
|2222||22||SSH (Secure Shell)||terminal access|
Port 8080 is used by an Apache server,
providing access to Hypertext Markup Language (HTML) files
Other servers will, of course, need to use different ports.
Port 2222 is used to access Perkify via SSH. Note that SSH can also be used to tunnel X11 and other protocols.
To be continued…