( string host [, string type] )
Searches DNS for records of type type
corresponding to host. Returns TRUE if any
records are found; returns FALSE if no records were found or if
an error occurred.
type may be any one of: A, MX, NS, SOA,
PTR, CNAME, AAAA, A6, SRV, NAPTR or ANY. The default is MX.
host may either be the IP address in
dotted-quad notation or the host name.
AAAA type added with PHP 5.0.0
This function is not implemented on Windows platforms. Try the
See also dns_get_record(),
gethostbynamel(), and the named(8) manual