DCOM Not working - starts/crashes intermittantly

[DCOMdefficient]

I posted this in the dcom group, but my problem is more of a OS/System one than a programming/api one.

I have been spending quite a few days trying to figure out why dcom stopped
working for no apparent reason. From my tests I have determined the problem
is in the OS. Tests include RPCPing and MS DCOM client/server test
application. I have also verified router ACLs at the facility level and have
worked with the developers. All dcomcnfg settings have been quadruple
checked - 3x.

When I stop and restart COM+ services dcom works for a few minutes and then
starts failing. Beginning yesterday it would start working for no apparent
reason for a few minutes and stop. The error reported by the app that uses
it is typically "The RPC server is unavailable.[800706ba]" The server had
been up only a couple of weeks when dcom inexplicably stopped working.

I have witnessed that the RPCPing enpoint search is successful when dcom
client/server test application fails

"CoCreateInstanceEx: The RPC server is unavailable<800706ba>"

Event logs will show the rather uninformative "DCOM was unable to
communicate with the computer a.b.c.d using any of the configured
protocols."

Here is a summary of the scenario:

Server1 - w2k3 hosting web sites. ms sql and running the web hosting
automation software (HC)
Server2 - w2k running remote DNS (SimpleDNS Plus)
Server3 - w2k running remote Email server (MailEnable)

HC uses dcom to communicate with Server2 and Server3 to provision the
various elements of web hosting accounts.

(Server2 used to serve the same purpose as Server1 until IIS became "full."
It communicated with Server3 in exactly the same way Server1 is supposed to
do now. Because server1 is not communicating I have switched back to server
2 as "primary" server).

What else can I look at or do? One of my theories is that for some reason
too many connections are created on port 135. Netstat doesn't seem to say
that but maybe I am wrong.

 

[PhillyCheeseSteak]

RPC is unavailable usually means a DNS problem when referring to other areas of windows, but other than that, i have no idea...
=(

-Phil

 

[DCOMdefficient]

DNS problem has been ruled out. Another server using the same dns server works....etc Thanks anyway

 

[xmsre]

RPC server unavailable is fairly generic. What ports are allowed between the servers? Are any of the networks using NAT? If you're doing NAT, you need to do some extra configuration for DCOM to work:

http://support.microsoft.com/default.aspx?scid=kb;en-us;248809

 

[DCOMdefficient]

All ports are open, no NAT.

 

[MarkMyers]

I am having this problem to. There is only one server involved. I am attempting to copy a project from VS.Net to the server which has been working fine to a long time but now I get the offending "DCOM was unable to communicate with the computer a.b.c.d using any of the configured protocols" message.

PhillyCheeseSteak, how did you rule out a DNS problem?

Has there been any solution found to this problem since April 1?

Thanks,
Mark.

 

[xmsre]

It could be a couple of things. First, have you applied 823980?

Is it really a W2K3 issue or is it a VS.Net issue with copying the project?

http://support.microsoft.com/default.aspx?scid=kb;en-us;833552