/etc/services file and Ports Concepts on Unix

On UNIX the /etc/services file maps port numbers to named services. The port numbers on which certain standard services are offered are defined in the RFC-1700 Assigned Numbers .The /etc/services file enables server and client programs to convert service names to these numbers -ports. The list is kept on each host and it is stored in the file /etc/services.  For each service, a single line should be present with the following information: official_service_name     port_number/protocol_name         aliases For example: [root@webmanual01 ~]# grep -w 80 /etc/services http 80/tcp www www-http # WorldWideWeb HTTP http 80/udp www www-http # HyperText Transfer Protocol The fields are as follows: http : Service name. 80 : Port number. tcp : Protocol name....