A Few of My Favorite Things: DCDiag
Compaq knows a thing or two about troubleshooting large networks. Here are some of the utilities and programs it uses most and likes best for Windows 2000.
In the Support Tools directory on
the Win2K CD, DCDiag provides a number of tests
that can help determine the health of individual
DCs, all DCs in a site, or all DCs in an enterprise.
When no tests are explicitly specified,
DCDiag tests connectivity, replication, topology
integrity, Check NC Head Security Descriptors,
Check Net Logon Rights, Locator Get Domain Controller,
Intersite Health, Check Roles and Trust Verification.
For each of these tests, DCDiag shows the success
or failure of the test with more detail provided
with the /v switch.
Although DCDiag features a number
of diagnostic tests, I use it most frequently
to quickly diagnose replication problems like
the one shown in the figure. It provides a quick
way to determine which DC replication partners
are unreachable and how long it’s been since replication
last occurred. Other tools also do this, but I
find DCDiag the easiest to use for a quick overview
that doesn’t require the use of lengthy GUIDs.
help you determine if a server has replication
problems. (Click image to view larger version.)
The following shows part of the output
obtained from running DCDiag on a DC (RISRV01)
when one of the other DCs (MASRVONE) isn’t available
on the network.
Check,RISRV01] A recent replication attempt failed:
From MASRVONE to RISRV01
Naming Context: CN=Schema,CN=Configuration,DC=cpqri,DC=com
The replication generated an
The RPC server is unavailable.
The failure occurred at 2001-05-06
The last success occurred at
20 failures have occurred since
the last success.
[MASRVONE] DsBind() failed with
The RPC server is unavailable..
The source remains down. Please
check the machine.
Although useful for detecting errors
on DCs, manual intervention is still required
to fix the errors that are detected.
Fred Grant, MCSE, is a senior technology
consultant for Compaq, Windows and Messaging Practice,
in New England.