HOST.CONF

HOST.CONF

NAME DESCRIPTION FILES SEE ALSO

NAME

host.conf - resolver configuration file

DESCRIPTION

The file /etc/host.conf contains configuration information specific to the resolver library. It should contain one configuration keyword per line, followed by appropriate configuration information. The keywords recognized are order, trim, multi, nospoof and reorder. Each keyword is described seperately below.

order

This keyword specifies how host lookups are to be performed. It should be followed by one or more lookup methods, seperated by commas. Valid methods are bind, hosts and nis.

trim

This keyword may be listed more than once. Each time it should be followed by a single domain name, with the leading dot. When set, the resolv+ library will automatically trim the given domain name from the end of any hostname resolved via DNS. This is intended for use with local hosts and domains. (Related note: trim will not affect host- names gathered via NIS or the hosts file. Care should be taken to insure that the first hostname for each entry in the hosts file is fully qualified or non-qualified, as appropriate for the local installation.)

multi

Valid values are on and off. If set to on, the resolv+ library will return all valid addresses for a host that appears in the /etc/hosts file, instead of only the first. This is off by default, as it may cause a substantial performance loss at sites with large hosts files.

nospoof

Valid values are on and off. If set to on, the resolv+ library will attempt to prevent hostname spoofing to enhance the security of rlogin and rsh. It works as follows: after performing a host address lookup, resolv+ will perform a hostname lookup for that address. If the two hostnames do not match, the query will fail.

spoofalert

If this option is set to on and the nospoof option is also set, resolv+ will log a warning of the error via the syslog facility. The default value is off.

reorder

Valid values are on and off. If set to on, resolv+ will attempt to reorder host addresses so that local addresses (i.e., on the same subnet) are listed first when a gethostbyname(3) is performed. Reordering is done for all lookup methods. The default value is off.

FILES

/etc/host.conf

Resolver configuration file

/etc/resolv.conf

Resolver configuration file

/etc/hosts

Local hosts database

SEE ALSO

gethostbyname(3), hostname(7), resolv+(8), named(8)