On Wed, 29 Jun 2016 17:00:24 -0400, Mayayana wrote:

I think you're right. I have all 3 dnsCache* values set
to 0. I ran into the problem awhile back when I couldn't reach a couple
of news sites for several days. They had changed their IP. I don't
remember what the default value is but it shouldn't be more than maybe
12 hours.

The question is *what* to set them to so that
the DNS cache is consulted *every* time Firefox
needs to resolves a domain to an IP address.

Here is what an about:config shows for "network.dns":
network.dnsCacheExpirationGracePeriod;60
network.dnsCacheExpiration;60
network.dnsCacheEntries;400
network.dns.offline-localhost;true
network.dns.localDomains;
network.dns.ipv4OnlyDomains;
network.dns.get-ttl;true
network.dns.disablePrefetch;false
network.dns.disableIPv6;false
network.dns.blockDotOnion;true

Which settings are the important ones that cause
Firefox to check DNS *every* time?

This is assuming you put 127.0.0.1 localhost as the first
line in your HOSTS file, and that the site you tested with matched the
subdomain string as well as the domain string. In other words, 127.0.0.1
abcdef.somewhere.com will only block abcdef.somewhere.com. It won't
block abcdefg.somewhere.com or www.somewhere.com.

Yes. This is the first non-comment line in the
WINDOWS HOSTS file:

127.0.0.1 localhost

Also, a side note: The Stormin' in home repair is
Stormin' Mormon, not Norman.

OOops.