Since early 2012 it has been mandatory for new or upgraded Internet
connected machinery and software to support IPv6 ad use it in preference
over IPv4.
Squid IPv6 behaviour has followed these practices since well before the
guidelines became a BCP. Over the years it has also grown into a
well-tested and widely used feature.
The --disable-ipv6 build option is now deprecated. It is long past time
to fix whatever network brokenness you may have that made it look
attractive in past years.
Squid-3.5.7 and later will perform IPv6 availability tests on startup in
all builds.
Where IPv6 is unavailable Squid will continue exactly as it would
have had the build option not been used.
These Squid can have the build option removed now.
Where IPv6 is detected but --disable-ipv6 prevents use Squid will log
āWARNING: BCP 177 violationā.
No need to worry. I see this message since 3.5.7 - each time I restart squid from consoleā¦