Host Information A domain database contains names. These names generally refer either to machines that are a part of the domain, or to sub-domains. This dialog allows you to define both. 11.. SSeettttiinngg IIPP nnuummbbeerrss ffoorr aa hhoosstt You can define up to four IP numbers per _D_N_S entry. There are four combo box edit fields. A help pop-up is available to assist you in selecting one (not already used) IP number. You must have defined your IP ranges first, using the IP allocation space menu of the main DNS configurator menu. 22.. SSeettttiinngg uupp aa ssuubb--ddoommaaiinn A sub-domain is a way to hand off authority to another administration. Setting a sub-domain involves mostly telling where the _D_N_S which manages this sub-domain is located. This is a two step process. First, you must define which machines are managing the sub-domain. Next, you must give the IP numbers of those machines, if they are part of the sub-domain. A _D_N_S of a domain need not be part of the domain it is managing. 22..11.. AAnn eexxaammppllee:: SSeettttiinngg tthhee ssuubb--ddoommaaiinn ssuubb..ffoooo..ccoomm Some facts first... +o This machine is the _D_N_S of foo.com. +o You want to create the sub-domain sub.foo.com. +o The primary _D_N_S of the sub-domain will be dns.sub.foo.com. +o The secondary _D_N_S of the sub-domain will be ftp.sub.foo.com. Perform these steps... +o Edit the record sub.foo.com (it will be a new file). +o Under the section DNS advertising enter dns.sub.foo.com and ftp.sub.foo.com. +o Edit the record dns.sub.foo.com and set the IP number(s) of this machine. +o Repeat the operation for ftp.sub.foo.com. Now your _D_N_S knows two things: Which machine(s) is(are) responsible for the sub-domain sub.foo.com, and, how to reach it. This information combination is often referred to as the _g_l_u_e _r_e_c_o_r_d. 22..22.. NNoott sseettttiinngg aa ssuubb--ddoommaaiinn It is not necessary to setup a complete sub-domain just to have a sub- category of machine. Suppose that for a project, you want to refer to two machines as ftp.project.foo.com and www.project.foo.com. You can simply define these machines' IPs using the host information screen. The information will be dispatched in the foo.com database. 33.. EE--mmaaiill aaddvveerrttiissiinngg It is sometimes necessary to redirect e-mail traffic for a host or domain, to a specific e-mail server. This is often done "domain wise" in the primary specification screen of a domain. It is sometimes necessary to do an exception for either one machine or a sub-domain. You can do this here, and specify up to three e-mail servers. 44.. DDeelleettiinngg oonnee DDNNSS eennttrryy The button Del of the dialog is used to delete this record from the DNS. A confirmation pop-up will let you confirm (or cancel) the deletion. Deleting such a record will clean up both the domain database and the reverse mapping.