AnyEvent::DNS::EtcHosts AnyEvent::DNS behavior to use /etc/hosts The DNS lookups are emulated. This resolver returns the standard DNS reply based on /etc/hosts file rather than real DNS. You can choose different file by changing PERL_ANYEVENT_HOSTS environment variable. This module also disables original AnyEvent::Socket's helper function which reads /etc/hosts file after DNS entry was not found. It prevents to read this file twice. The AnyEvent::Socket resolver searches IPv4 and IPv6 addresses separately. If you don't want to check the addresses in DNS, both IPv4 and IPv6 addresses should be placed in /etc/hosts or the protocol family should be set explicitly for resolve_sockaddr function.