Very weird Squid issue
-
I have a client that is having trouble reaching Instagram. The DC is the DNS server and uses the IP of the router as a DNS forward as well as the IPs of OpenDNS and Google. On the server, if I do an nslookup for instagram.com I get hits. If I do an nslookup for www.instagram.com I get no results. If I try to connect with Squid running then Instagram never loads and gives a DNS resolution error. Makes sense if the DNS server can't resolve then nobody can resolve. However, if I drop Squid, I still can't resolve www.instagram.com but I'm able to load the pages. Very strange. Can anyone help?
-
I may have solved this and I'm not sure why turning Squid on and off changed anything, but there was a static entry in DNS set for facebook to resolve to 127.0.0.1 to restrict users. Since Instagram is part of Facebook it was locked out. Why turning off Squid allowed it to work sometimes is a mystery to me but I think the DNS setting is the issue.
-
If Facebook now owns Instagram, could it be that some Instagram services are co-mingled with Facebook servers? If you're blocking the "Facebook" domain, depending on how Instagram resolves, it may land on a blocked Facebook server. Other times when pfSense is resolving Instagram it could resolve to a non-blocked (not Facebook) server. I think I read that pfSense uses the first IP of a domain and it will re-resolve when it needs to.
(?)
Just a shot in the dark.