Back UP AD Server not working.....

[murrayw]

I have 2 AD servers. I was under the impression that if I had 2 for redundancy then if 1 went down the other would seemlessly perform its tasks - i.e dns, logons etc.

This is how they are:

(2) FSMO roles, DHCP, DNS (its also the dns server 1st for name resolution)
(1) DNS (second in ipconfig for name resolution),DHCP

If I turn off the AD server (2) holding the fsmo roles and the one people use as their 1st dns server the network falls apart - exchange disconnects, dns fails. Shouldn't (1) start to take these requests?

Replication work fine. If I turn off (1) the network runs fine. The only problem is if I turn of (2)

 

[Davetoo]

Start with the obvious..is your 2nd AD server a GC? Is DHCP advertising both servers for DNS?

I'm Certifiable, not cert-ified.
It just means my answers are from experience, not a book.

There are no more PDC's! There are DC's with FSMO roles!

 

[Zelandakh]

This is usually a DNS issue. Can a client ping and \\?

 

[murrayw]

Yes I have just checked bith servers are GC servers.
Yes both DHCP servers give out both dns, router etc - they give out the same info.

Also there are no extinct servers in sites and services - I try to keep AD tidy.

 

[Davetoo]

Ok, weird. Did you try what Zel said? What are the results?

I'm Certifiable, not cert-ified.
It just means my answers are from experience, not a book.

There are no more PDC's! There are DC's with FSMO roles!

 

[Zelandakh]

I hope only one DHCP server is running...

 

[murrayw]

I can ping both servers and connect via UNC path.

Both servers have dhcp running but they both use different ranges i.e (2)50-80, (1)10-40 - this is something I inherited and the old IT Manager who wanted 2 DHCP scopes running for redundancy. i have never removed it since he left.

I turned (1) off for 3 days no problems the metwork performed as it should.
Today I tested (2) as soon as it went down - chaos. all outlooks start asking for username and password to log in. the intranet site - no one could log in.

 

[Zelandakh]

OK, so at that point do they have an IP address? Can you ping the DG? Can you ping the DNS? Can you go to nslookup and connect to DNS and resolve addresses?

This feels like a DNS issue.

 

[murrayw]

I think you are 100% correct - DNS all round.

I have been through both DNS servers and found stacks of ptr and ns records that should not be there. quite alot of duplicates.

i have tidied up the dns and will retry my experiment tomorrow morning and shut down (2) and see what the impact is.

 

[Zelandakh]

It is almost always a DNS issue

 

[murrayw]

I will test tomorrow then award

 

[Zelandakh]

Test tomorrow then report back progress. Award? Ooh!

 

[murrayw]

will test tomorrow. other issus to content with this morning

 

[Zelandakh]

Let's hope your DC doesn't pop on you today then!