checkdnsrr  --  Check DNS records corresponding to a given Internet host name or IP address
dns_get_record  --  Fetch DNS Resource Records associated with a hostname
gethostbyname  --  Get the IP address corresponding to a given Internet host name
getmxrr  --  Get MX records corresponding to a given Internet host name
getprotobyname  --  Get protocol number associated with protocol name
getprotobynumber  --  Get protocol name associated with protocol number