* multi-threading - use pthread.h? * can't handle wildcarded domains that return more than one IP address on non-existing subdomains test domain: proboards.com * allow using a customized list of DNS server to share network load * allow using DNS server supplied on the command line * for openDNS users: document how to permanently change DNS server settings so they are not overwritten by DHCP settings * convert hostent structs to addrinfo ? * replace inet_ntoa(*((struct in_addr *)host->h_addr_list[j])) with ipstr * obtain aliases for each domain (CNAME records)? * clever numerical domain bruteforce for clusters. i.e.: www2, www3 * pickup new subdomains via reverse lookups (PTR records) * better input validation * improve function that validates target domain