sbs 2011 internet issues

[autumn]

G day all

I'm having an issue with a SBS 2011 server network. So there is the SBS server, an 2008 Server std (for remote desktop), Dlink DSR500N switch and about 15 computers.

Now the issue looks like an DNS issue, as the workstations will take several tries refreshing before the page will be displayed.

I've tried the regedit fix below, I've disabled IPv6 on Workstations, I have read that it could be a Dlink modem issue (not to sure if that's meant to be router or modem, changing the DSR is more of a problem as I've VPN's set up as well, I have replace the modem, which is in bridged mode). I've set the forwards to local ISP servers as well as opendns servers. Each step seems to have fixed it a little but still not 100%.

I don't think it's the router as I've set a couple of the workstations manually to the router or external servers and it seems to be 100%.

any help would be greatly appreciated.

Reg fix.

"HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\Parameters

3. On the Edit menu, click New, click DWORD (32-bit) Value , and then add the following value:

Value: MaxCacheTtl
Data Type: DWORD
Data value: 0x2A300 (172800 in decimal = 2 days)"

 

[YeOldeStonecat]

I'd do some more verification that DNS is setup correctly on the entire network.
SBS Server needs to look at itself for DNS...and only itself...period...nothing else.
Member server and workstations need to look at the SBS Server for DNS...only that, nothing else.

SBS servers DNS Management...go into forwarders and make sure it's setup to use some good forwarders...I use Open DNS or Nortons SafeSearch DNS services. Common practices to use ISPs DNS servers too...but I prefer the added layer of security against maleware for my clients by using safe dns services.

Make sure that DStink router isn't double NAT'd behind an ISP supplied gateway that is also running as a router....the one router should have a public IP address on its WAN interface.

 

[cyabro]

I've got a client with what sounds like the exact same problem also with an sbs2011 box.
I've also tried the fixes you've mentioned and a ton more but the users still complain of slow Internet.
Whenever I do tests in the network and Internet I can't fault it, they have a 50mpbs down and up fibre connection which is getting those speeds.
I always come back to dns being the problem and suspect that it is just broken in sbs2011.
The ISP has changed all their equipment twice and I've changed hardware inside the network like cabling, new switch, new network card in the server etc but the problem keeps coming back.
I've basically given up on it now as I've spent way too much time on it that can't be billed to anyone.

 

[YeOldeStonecat]

I forgot to add...correct antivirus real time file protection exclusions have been done on the server? Because there are a crap load of them with SBS....doing a default AV install is not good...nope...not good.

What specs are the server? RAM, and specifically..hard drive type..and setup of volumes?

 

[bluecoast]

I was having the same issue randomly on my own SBS2008 box. Randomly, I would get an error on sites I knew were up. A simple refresh would bring the page up. I followed the same logic and ended up troubleshooting DNS. The issue seemed to clear up when I added a second forwarder to the DNS server. The second forward was to the router which used the same OpenDNS records...

For reasons I will probably never discover, that seemed to fix it. The only explanation I can come up with is that the router's packet inspection or PAT somehow messed with the DNS queries unless they hit the routers DNS server.

Be very careful disabling IPv6, there are many wrong ways to do it. Unchecking IPv6 in network properties does more harm then good IMO. All good for troubleshooting, but if that did not fix the issue I would consider re-enabling.

 

[autumn]

Thanks all.

Thanks to bluecoast setting the router in the dns forwarders looks like it's done the job. what a pain that was.

Regards

Tim