sbs did not pickup dc / dns function when another server crashed

[micahdaniel]

I have a small 2003 domain including 2 DCs (one sbs and one Enterprise). The other day a power supply failed on the Enterprise server and all internet access was lost and xp pro desktops got balloons saying working offline.

I'm trying to determine why the sbs server did not pick up the dc/dns responsibilities and keep things afloat. I found event ID 409 in it's event log. It has been logged about once a week, yet the ip addresses appear to be configured properly in the dns properties for that server. I actually found that the 409 event id has been consistently poppling up for over 2 years!

I need help diagnosing this issue or at least making sure it doesn't happen again.

Am I right in thinking the sbs should have taken over?

 

[mrdenny]

I don't think you can have a second domain controller in an SBS domain can you?

Any way, a second domain controller won't just take over the existing services. You'll have to have all the clients configured to use both machines as DNS servers, and have both DCs configured as global catalog servers.

How is the DNS config for your client computers setup?

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[biglebowski]

I always thought that SBS would stop functioning after 21 days if it detected another DC (21 days being the time allowed for an upgrade)

Biglebowskis Razor - with all things being equal if you still can't find the answer have a shave and go down the pub.

 

[NetworkTek]

You can have multiple dc's in an sbs environment. You can't have multiple sbs servers in the same environment. The sbs server must hold the fsmo roles. It sounds to me that your pc's were only configured to use the one dns server. For redundancy purposes it would be a good idea to have your machines configured to look at both servers for dns. If you use dhcp that would be configured in the dhcp options on the dhcp server. If the machines were not able to contact a dns server it would have severely limited your network functionality. So first I would investigate the dns settings on your pc's.

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[micahdaniel]

ipconfig all on my desktops shows both servers under dns as we have intended them. I installed updates, rebooted and then I checked the event log and there was a fresh 409 event there.

I checked dhcp settings on the enterprise and the sbs was not mentioned in the options, so I added it. I'm not sure if that matters though since both show up under dns when I do the ipconfig /all on the desktops.


I fairly certain that the sbs came first and the enterprise was added later. I'm not sure what you mean by fsmo roles.

The 409 event id reads thus:

"The DNS server list of restricted interfaces contains IP addresses that are not configured for use at the server computer.

Use the DNS manager server properties, interfaces dialog, to verify and reset the IP addresses the DNS server should listen on. For more information, see "To restrict a DNS server to listen only on selected addresses" in the online Help.

 

[micahdaniel]

OK, I verified that the sbs in question holds all the fsmo roles. I also verified that the server is only listening on the correct addresses (as recommended by the event ID fine print) --also verified in the registry. I'm still at a loss as to why I continue to get the 409 entries and why the server failed to provide DNS/DC functionality when the other DC crashed. Any ideas?

 

[micahdaniel]

Forgot to mention, I checked our desktops also and they list the sbs along with the other in the DNS section of ipconfig /all.

 

[58sniper]

You can have multiple domain controllers in a domain that SBS resides in. That's pretty common. Make sure that the additional DCs are Global Catalogs, are DNS servers (and DNS is correctly replicating to them). Make sure that the additional domain controllers are assigned to the correct AD site, and that all subnets are defined.

You can also have multiple SBS servers on the same network - just not part of the same domain (to clarify a statement from above). Attempting to have multiple SBS boxes on the same domain will cause them to shut down.

Once that's done, do some simple testing, including dcdiag, netdiag, etc.

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[micahdaniel]

The other DC is a DNS server also and appears to be functioning properly in the same domain. I did dcdiag and netdiag on both and found nothing out of the ordinary.

I wonder, when I go to the interfaces tab of properties in dns where it lists what ip's to listen on, I show it is listening on the ip of the sbs and the ip of the other server. Shouldn't it only list the ip address of the sbs (since this is the dns settings for this particular dns server)? Perhaps this is why I'm getting the 409 error. It's set to listen on an ip that doesn't even exist on that server!?

Anyway, I'm deleting that extra ip and we'll see what happens...

 

[micahdaniel]

That was the problem. I guess when I had looked at that interfaces tab before I had assumed it was listing the other IP because that was the IP of the other DNS server.

No more 409 event id's and desktops have regular network functionality--though I did notice a lag of a few seconds while browsers began resolving urls. Presumably because they were first trying the enterprise dns and then went to the sbs.

 

[58sniper]

That's correct. Computers only switch to the second DNS server when there is NO REPLY from the first. Glad to see it's resolved.

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/