301 Redirects From HTTP>HTTPS & Naked Domain > WWW not working on AT&T's 4G Network

Question

I have a really odd 301 redirect failing issue that I can't seem to wrap my head around why.

I have a netscaler device with responder policies that move http traffic onto https and naked domain traffic onto www.

• They are working perfectly on Windows desktop devices through Chrome and Firefox.
• They are working perfectly on mobile devices tethered to Wi-Fi.
• They are working perfectly on mobile devices on 4G with Sprint and T-Mobile.

They are completely failing on AT&T 4G.

I have tested this with a multitude of Android devices and iOS devices on AT&T and all exhibit the same issues: a 504 response. Here is the output which I got by tethering my phone to my PC and firing up Fiddler.

GET http://thedomain.org/ HTTP/1.1
Host: thedomain.org
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Cookie: REDACTED
Connection: keep-alive
Upgrade-Insecure-Requests: 1


HTTP/1.1 504 Fiddler - Receive Failure
Date: Thu, 10 Nov 2016 22:20:27 GMT
Content-Type: text/html; charset=UTF-8
Connection: close
Cache-Control: no-cache, must-revalidate
Timestamp: 16:20:27.867

[Fiddler] ReadResponse() failed: The server did not return a complete response for this request. Server returned 0 bytes.                                                                                                                                                                                                                                                                                                                                                                          

I obviously have begun the process of speaking with AT&T about this, but has anyone any suggestions at all as to why this may be occurring? My whole team is stumped at present.

UPDATE 11/11 09:30

So these were the exact issues we were experiencing yesterday

DOES NOT WORK FOR THE AT&T SUBSCRIBERS WE’VE SEEN SO FAR:

• Opening the Android stock web browser specifically and typing into the address bar: thedomain.org
• Opening the Android stock web browser specifically and typing into the address bar: www.thedomain.org
• Opening any web browser on mobile and typing into the address bar: http://www.thedomain.org
• Opening any web browser on mobile and typing into the address bar: http://thedomain.org
• Opening any web browser on mobile and typing into the address bar: https://thedomain.org

The network provider was quick to blame AT&T. However!

They added a rule for the last use case which was failing on all networks to redirect https://thedomain.org to https://www.thedomain.org and lo and behold it also fixed the rule for AT&T users. I still don't know why yet, I am guessing some kind of refreshing of the rules in netscaler fixed the issue on the load balancing device, but as I stated to them, I'd take a fix over an explanation in the short term.

If simply re-applying the rest of the rules is the fix, I will update this with an answer.

Answer 1

I would recommend that you do detailed analysis of the FQDN(fully qualified domain name) dns lookup from each network separate from the html requests. If the dns entries for your domain do not have the appropriate records to associate the domain name minus the host component with the ip address of the web server it is to a certain extent related to missing dns record entries.

A number of cellular providers appear to be using proxy servers for web browsing...so the error you have regarding missing content may actually be an indication that the dns lookup failed on the web-proxy....so you are getting a different message than if your browser were going direct and the dns failed.