I have inherited a site: Win2K11 SBS server with a fairly standard looking setup. They have an ISP provided Zyxel D1000 dsl modem/router.
I am attempting to install a Sonicwall TZ205: I have put the d1000 in bridge mode (changed its i.p. address), configured the sonicwall with the original i.p. address of the d1000 and opened the ports for exchange, owa etc.
The sbs2011 box is doing dhcp & dns on the server. There is no proxy server on the network.
Everything works except for web browsing, which is erratic. Some sites cannot be accessed at all, but they can be pinged and do appear to resolve but time out, this is not limited to any one tld.
For example microsoft.com resolves to http://www.microsoft.com/en-us/
but the site never loads, it either times out or cointinuously tries to load.
This behaviour is confined to the domain joined machines on site! My own laptop, whether connected to wireless or wired to either the sonicwall or to the switch has no problem accessing any sites!