Services
The last portion of Overview page we still have to discuss features a list of network services.
The entries of this list are the services that were observed since the beginning of the analysis.
But what's exactly a service?
A network service, also known as upper layer protocol or application layer protocol, is to be intended as a standard defining the rules to carry a specific kind of information.
There are hundreds of different services, each one used for a peculiar purpose.
Sniffnet supports more than 6000 services, including upper layer protocols, trojans, and worms.
In the following are reported some examples of the most common services with the respective function.
| Service | Function |
|---|---|
| HTTP | Documents transmission for the World Wide Web |
| DNS | Translation of human readable domain names into IP addresses |
| SSH | Secure remote login and file transfer |
| DHCP | Automatic IP address assignment to devices part of a network |
| IMAP | Retrieval of email messages from a mail server |
Tip
Having a look at the services involved will immediately give you a better idea about the nature of your Internet traffic.
By default, services are sorted according to most recent timestamp they were last seen, but you can decide to change their order by clicking on the double arrows icon; in this way, you can set the services to be ordered according to most or least amount of data exchanged.
Network services are inferred from the transport protocol and port number, following the convention maintained by IANA.
Sniffnet's list of services is generated from Nmap's service collection
and is available in the file services.txt.
Warning
The Internet Assigned Numbers Authority (IANA) is responsible for maintaining
the official assignments of port numbers for specific uses.
Remember that this a convention, not a strict rule: many unofficial uses of well-known port numbers occur in practice.