user accounts User accounts in _L_i_n_u_x are all stored in the same database. _L_i_n_u_x_c_o_n_f splits these accounts into different categories based on known prac- tices. Each category has its own menu entry. 11.. NNoorrmmaall aaccccoouunnttss 11..11.. EEddiitt//CCrreeaattee uusseerr aaccccoouunnttss Use this menu to create normal shell accounts. 11..22.. GGrroouupp ddeeffiinniittiioonnss Users are member of groups. Use this menu to create and manage groups. 11..33.. CChhaannggee rroooott ppaasssswwoorrdd Use this menu to change the superuser password (root) 22.. SSppeecciiaall aaccccoouunnttss Many user accounts are used to control specific tasks. These accounts have special purposes. They have a user ID and belong to a group. They also have a password. These accounts are not meant for human beings, however; they are for system use. 22..11.. EEddiitt//CCrreeaattee PPPPPP aaccccoouunnttss vviiaa nnoorrmmaall llooggiinn These accounts let a remote machine connect and establish a network connection using the PPP protocol. The remote system must identify itself using a standard chat sequence, sending its username followed by a password. 22..22.. PPPPPP aaccccoouunnttss vviiaa PPAAPP aauutthheennttiiccaattiioonn These accounts are meant for authentication using the PAP protocol. The username and password are exchanged using a special protocol defined in the PPP standard. 22..33.. PPPPPP aaccccoouunnttss vviiaa CCHHAAPP aauutthheennttiiccaattiioonn Same as the PPP accounts above, except that a different, more secure, protocol is used to exchange authentication. 22..44.. SSLLIIPP aaccccoouunnttss vviiaa nnoorrmmaall llooggiinn SLIP is another way of establishing a network connection between two computers over a serial line (usually a modem). 22..55.. UUUUCCPP aaccccoouunntt UUCP is the Unix to Unix Communication Protocol. UUCP is used for batch-oriented data transfer. It allows unattended exchange of files (and e-mail) between two computers. It provides a very inexpensive but highly reliable way to automate data exchange. It is probably the best way (by far) to receive and send e-mail on the Internet unless you have a dedicated connection to your service provider. See the networking section of _L_i_n_u_x_c_o_n_f to configure UUCP. 22..66.. PPOOPP aaccccoouunnttss ((mmaaiill oonnllyy)) POP accounts are restricted accounts. POP users can't get a shell. They are generally used to retrieve e-mail using the POP (Post Office Protocol). They can also be used to connect to other services such as Samba (file and print service for DOS/Windows machines). 22..77.. VViirrttuuaall PPOOPP aaccccoouunnttss ((mmaaiill oonnllyy)) These accounts are even more restricted. They allow retrieval of e- mail using the POP protocol, from virtual e-mail domains. See the menu "Networking/mail delivery system (sendmail)" to configure virtual e- mail domains. 33.. EE--mmaaiill aalliiaasseess E-mail aliases may be considered special virtual user accounts. They allow the redirection of e-mail from one account (which may or may not exist) to one or more other e-mail addresses. 33..11.. EEddiitt//CCrreeaattee mmaaiinn ddoommaaiinn uusseerr aalliiaasseess Use this to manage aliases for the main e-mail domain. 33..22.. vviirrttuuaall ddoommaaiinn uusseerr aalliiaasseess This lets you do the same for each virtual e-mail domain. 44.. OOtthheerr ssttuuffff 44..11.. PPaasssswwoorrdd && aaccccoouunntt ppoolliicciieess You can control the rules for password validation and some default operating parameters associated with the accounts. 44..22.. PPoolliicciieess ffoorr vviirrttuuaall ddoommaaiinnss You can specify defaults on a virtual per virtual domain basis. 44..33.. AAvvaaiillaabbllee uusseerr sshheellllss Many shells are available in _L_i_n_u_x. You define them here. 44..44.. AAvvaaiillaabbllee PPPPPP sshheellllss These shells control the parameters of a PPP session. 44..55.. AAvvaaiillaabbllee SSLLIIPP sshheellllss These shells control the parameters of a SLIP session.