On Monday 05 February 2024 at 17:32:51, Rob van der Putten wrote: > Hi there > > On 05/02/2024 17:16, Dieter Bloms wrote: > > On Mon, Feb 05, Rob van der Putten wrote: > >> After upgrading Squid from 3 to 5 the percentage of IPv6 reduced from > >> 61% to less then 1%. > >> Any ideas? > > > > yes, since squid5 the happy eyeball algorithm as described in rfc 8305 > > is used. > > If your ipv4 connectivity is better than ipv6 than ipv4 is used. > > I'm not quite sure how this is established. It prefers IPv4 even when > the IPv6 ping is slightly smaller. I believe ping (ICMP) timings are irrelevant. The client (squid in this case) does a DNS lookup for the hostname's A and AAAA records, then makes two simultaneous HTTP connections to the server (one IPv4, on IPv6) and whichever one responds first *by HTTP* is then regarded as being the best way to route traffic thereafter. So, if you want to understand how this is doing what it is, I suggest you perform a packet capture of HTTP traffic and look at the requests and the response timings. Antony. -- I want to build a machine that will be proud of me. - Danny Hillis, creator of The Connection Machine Please reply to the list; please *don't* CC me. _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx https://lists.squid-cache.org/listinfo/squid-users