This past Friday I moved a client into a new office. The same router, server, and switches are being used at the new location. Everything seemed to come up and online fine. We connected their existing router to the new ISP Modem (Comcast Cable 100 MB down circuit). Configured the WAN interface of the Router, brought up the server and changed the DNS forwarders to the new ISP DNS, and changed their MX record for Exchange. Mail began flowing and although there was a lot of running around anytime I needed to use the Internet is seemed fine.
The SBS server is the DHCP server and DNS (of course).
I was at the clients location Monday and about mid morning I was getting complaints that the internet was down. I started to investigate. Please bear with me as I try to explain the symptoms, as I am not seeing anything glaringly obvious as to what the issue can be.
At first I couldn't resolve DNS from the modem or the router, I bounced both and once both came back online I was able to resolve DNS from the GUI's of both the Comcast Modem and their Cisco router (RV180W).
Since that initial reboot of the equipment never have I not been able to resolve a host using ping or tracert. I am not seeing any packet loss using ping over extended times, either.
Connectivity to the Server and Exchange are fine.
At times browsing is great and I have performed speed tests that show they are getting close to 100 Mb down and 20 Mb upload.
When browsing stops or slows the symptoms are best seen as the browser seemingly stuck on waiting for www.domain.com. Sometimes a page like msn.com will come up right away, but there is a lot of white space on the page as images are slow to load or never load. Google news will do the same thing. At times a google search will do fine with it's autosearch feature, but as you click on results you will get many time outs and 404 errors.
There are no event viewer errors regarding DNS on the server.
I have tried OpenDNS forwarders, Google forwarders, using root hints instead of forwarders, MaxCacheTTL is set to 2 days and EnableEDNSProbes is 0.
I have a PC there that is not part of the domain and I have set the DNS entries to the ISP ones and I do not see the same issues as elsewhere.
Today I cannot RWW into the server. OWA works, and I can log onto the RWW site fine, but when I try to connect to Server it times out with an internal error (50331660).
I have tried a different router, restarting DNS service, Clearing DNS Cache. after a server reboot it seemed to take off for about 15 minutes then everything went to pot again.
I am running out of ideas and hoping for some input!