Setting up a domain definition Introduction 11.. ttaasskkss This machine may act as a DNS server for several domain at once. It may act as a DNS even for domain other than its own. In fact, it is not uncommon to see server providing DNS services for completely foreign domain. To setup a new domain, you must fill a form. Fortunately, _L_i_n_u_x_c_o_n_f can setup suitable default for all fields except one. Here they are... 22.. DDoommaaiinn nnaammee oorr IIPP rreevveerrssee mmaappppiinngg The dialog to create a domain name is similar to the one used to create an IP reverse mapping. The first field is either a domain name or an IP number. 22..11.. DDoommaaiinn nnaammee You must enter the domain name. A domain name is a bunch of names glued together with dots. For example solucorp.qc.ca can be read as the sub-domain solucorp, part of the sub-domain qc, itself part of the top-level domain ca. Unless you have an isolated network, you must request an official domain name. Say you want to register the domain foo.com, you will have to request permission to the authority managing the domain com. If later you want to setup the domain sub.foo.com, you will have to ask ... yourself, since you will be the authority of the domain foo.com. Your Internet provider will help you selecting a proper domain name. If you are not connected to the Internet, you are free to setup any domain you want. 22..22.. IIPP nnuummbbeerr When setting up a pseudo domain for IP reverse mapping, just enter the prefix of the network number. For example, if you are setting an IP reverse mapping for network 192.168.1.0, just enter 192.168.1. You can also enter the longer 1.168.192.in-addr.arpa and Linuxconf will translate that correctly. 33.. MMaaiinn sseerrvveerr Several machine may act as a DNS for a given domain. One of those servers is the _p_r_i_m_a_r_y. All other are backup and are called _s_e_c_o_n_d_a_r_i_e_s. The machine where you setup the DNS for a domain is normally the main server of that domain so the default provided is correct. 44.. AAddmmiinniissttrraattoorr eemmaaiill You must provide the email address of the person in charge of the DNS of this domain. An alias is acceptable, but make sure it effectively point to someone. This email address can be queried using the DNS itself so is useful information. 55.. DDNNSS aaddvveerrttiissiinngg 66.. EEMMAAIILL aaddvveerrttiissiinngg You can define which host is responsible to collect mail for the entire domain. This host may be unrelated to the domain itself. Off course, it must be configured to relay the messages to the proper mail server of your domain. You can define a backup for this host. If the host is not reachable email will be automaticly forwarded to those backups host. 77.. DDeeffaauulltt IIPPss One popular practice is to assign an IP number (or more) to a domain itself. For example, many will assign the same IP number to the www server of a domain and the domain itself. This allows one to browse either by doing http://www.domain.com or simply http://domain.com. _L_i_n_u_x_c_o_n_f allow you to set the default IPs of the domain right from here. Doing so, it will enter the proper records in the DNS. It will do so but won't modify the reverse mapping of the IP number. This means that two following command for example nslookup domain.com nslookup www.domain.com will produce the same result (the same IP numbers). But if on type nslookup The_IP_number_of_www.domain.com he will get www.domain.com as a result and not simply domain.com. 88.. SSeeccoonnddaarriieess rreeqquuiirreemmeennttss Secondaries are DNS machine which take a copy of selective domains of your DNS. Secondaries must be defined in the parent domain.