On 20/02/20 5:43 pm, Ahmad Alzaeem wrote: > Hello Amos , > You are correct , but are plan is using IPV6 as possible . > As I said the IPV6 of dual stack as like 98 % IPV6 . > > My question is how squid or under which circumstances can go to IPV4 as long as IPV6 dual stack exist ? How come it used 98 % for FB IPV6 destinations as an example and 2 % FB IPV4 destinations . > Could be any number of reasons. - the IPv6 pipe on your network being full making the IPv4 routes faster sometimes. - other transient routing issues causing connection failures when IPv6 was tried, Squid falling back to IPv4 which worked. - DNS resolver failing to supply AAAA fast enough so Squid uses A result for some connections. ... or a mix of all reasons. > Is it random process or DNS answers type ? DNS answers using "Happy Eyeballs" algorithms. With AAAA results preferred over tried before A results when both are available. > Also Have not found squid directives for this area . > > > Is there an option to tell squid use AAAA DNS reply from DNS for certain websites always or even with certain squid process ? And others non Dual stack use default case ? > The BCP specifications require both to be supported with a preference towards IPv6 whenever possible. That is what Squid does. We only provide the --disable-ipv6 and dns_v4_first for networks with seriously broken IPv6 setups, and both already deprecated. Amos _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
