Suddenly can't access certain internet sites, etc

[MoodyM]

I've been running the first macOS beta since day one, no issues. Went on holiday last week, came back today, booted my 2013 rMBP, suddenly can't connect to certain web sites. It appears to be random, for example:

eBay - no
MacWorld - no
Google - ok
Reddit - ok

What's weird is if I use Parallels to boot into Windows 10, or use Boot Camp to boot natively to Windows 10, all these sites are fine.

Don't think it's just a Safari issue though as my Dropbox icon in menu bar is showing that it can't connect and I can't download anything from the Mac App Store either.

Rebooted BT Home Hub 5 and rMBP, no luck. Tried at my parents house using their wifi, no luck.

Tried Chrome in macOS and all these sites work fine?

Any ideas?

 

[Queen6]

Check the DNS settings in Networking, as may be related to your ISP. Can always try Googles DNS 8.8.8.8

Q-6

 

[MoodyM]

Mine have always been set to Google's, so I tried clearing it back to my ISP assigned ones, problem persists
[doublepost=1468069093][/doublepost]I have just found the problem - in System Preferences > Network > WiFi > Proxies, the "Web Proxy" box was ticked, with 127.0.0.1 in the address field and 8228 in the port field. I unticked it, and all is working now. How on Earth that setting got like that I have no idea?