ignore_unknown_nameservers
Squid normally checks that DNS replies come from the same IP address to which the query
was sent. If the addresses don’t match, Squid writes a warning to
cache.log and ignores the reply.
Some installations use an /etc/resolv.conf trick to query any local
name server. If the name server IP address is 0.0.0.0, DNS queries are broadcast on the
local area network. The replies, however, come from specific
addresses. If you want to use this trick, you must disable the
ignore_unknown_nameservers directive.