I posted the same question a few days ago and haven't gotten anywhere yet with any of the suggestions of the two experts that responded, so I am reposting to see if I can get other experts to chime in.
I have a client with an SBS 2003 server which seems to be limiting their access to their online banking and some other sites. It started happening about 2-3 weeks ago. The server is the gateway and DHCP server connect to the internet with DSL- 2 NIC setup. Plugging a pc directly in to the DSL modem works fine. There are less than 10 clients on the network, and all have the problem.
Sometimes the wepages will load - very slow, other times not at all. Yahoo.com will not load at all. However when I use ip 18.104.22.168 in a browser Yahoo loads fine. Experts-exchange.com will not load either by name or ip. Microsoft updates website sometime loads. Google almost always loads. Cnet.com loads, however when trying to download files such as malwarebytes etc from cnet, file will not download.
It isn't browser specific as same results with Firefox & IE.
I've deleted forwarders, changed to OPEN DNS forwarders, I've update all root hints, i've flushed DNS and registered DNS etc.
I have my own SBS2003 system and the forwarders and root hints there are identical and I am not having such problems.
I have also deleted the forwarding zones in the DNS - there was one for "company".local and _msdcs."company".local. How do I restore these?