Re: Delegation through Linked Server Stops working

So then you followed everything in the troubleshooting
delegation doc? No one has every really posted any
resolution. I had posted a lot of steps Microsoft will have
you do when/if you open a ticket. That's about all I know
about it. It's not really a SQL issue, it's a kerberos
issue. Whether it's AD problems or issues with tickets
expiring, it's hard to say.


On Tue, 29 Aug 2006 14:38:02 -0700, DallasBlue
<DallasBlue@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

yes, when we restat the nodes the kerberos delegation starts to work for few
minutes and then stops with the 'login failed reason (null)' error....

"Sue Hoegemeier" wrote:

Are you having a completely different issue?
This post was about delegation working and then suddenly
failing until a reboot. Is this your issue?


On Sun, 27 Aug 2006 12:23:01 -0700, DallasBlue
<DallasBlue@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

Is there a solution for this issue.

delegation on linked server fails in our network when we use
nt-authenticated logins. we have a sql server 2000 nodes (n1,n2) on win 2003

Any thots,hints,links,pointers appreciated


"Sue Hoegemeier" wrote:

A few others have reported similar issues - with no
solutions. I worked at a place where we had delegation
sporadically failing and then working after reboots. A
ticket was opened with Microsoft but the issue was never
resolved. I would guess it's a Kerberos issue, not a SQL
issue. Make sure AD is clean and you don't have duplicate or
bad SPNs for all machines involved. Make sure all machines
involved have times sync working correctly, using the same
time server.
I'd suggest getting the Kerberos Delegation troubleshooting
doc available at:
We also installed a tool that would do verbose logging for
Kerberos errors - I just looked and couldn't find the tool.
Maybe if someone else knows they will jump in and provide a
link for that tool.
It can be a difficult issue to troubleshoot and you may want
to consider opening up a support ticket with Microsoft
Product Support.


On Wed, 16 Aug 2006 12:43:01 -0700, Sheriff
<Sheriff@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

I have a Linked Server from SQL 2005 to a SQL 2000 server. I have it
configured to use delegation. This will work fine for a while and then
suddenly stop working. Sometimes it works for an hour, sometimes for a day.
I have to restart the SQL 2005 server and it will begin to work again. The
error is:

TCP Provider: An existing connection was forcibly closed by the remote host.
Login failed for user '(null)'. Reason: Not associated with a trusted SQL
Server connection.

Any ideas?