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Unable to connect to Server via RPC or DCOM

We have applications that connect through DCOM and RPC to a main server, but this server is no longer allowing connections on port 135. I have performed a port test from several other machines in the same domain, but it is not accepting requests from anywhere. I have also attempted to Telnet using port 135 but this doesn't work either.

In addition to the above I have performed a netstat -a on the affected server and it states that there is a connection over port 135 to one of the domain controllers, but when I perform a port query to the affected server from the domain controller it comes back as not listening.

Finally I have performed a Wireshark capture on the server and when a SYN packet comes through the affected server responds with a RST ACK which also suggests that the port isn't listening.

Could anyone shed any light on how I might resolve this issue? I know that a reboot will fix the problem in the short term but in a week or so the problem will reappear, so I am looking for something a little more permanent.

Thanks in Advance
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Martyn Lawson
Asked:
Martyn Lawson
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1 Solution
 
Rich WeisslerProfessional Troublemaker^h^h^h^h^hshooterCommented:
Don't know that I have a solution... but if I were looking at this, the next thing I'd look at would be 'netstat -ab' ... and see if I can find what might be misbehaving.  

And if it comes back reporting 'svchost.exe', might switch to 'netstat -ao'  (and I habitually use 'netstat -aon' so I don't have to wait for name resolution anyway), to get the PID, then ask 'tasklist /svc' which services are using that svchost process.
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And attacking the problem from another direction, I might comb thru the Event Viewer, probably concentrated in the SYSTEM Event Log for errors, especially around the time the problem started.  I'm hoping there will be a DCOM error in there, which will probably give you the GUID of the component which is hanging.
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compdigit44Commented:
Where there any y change on the server recently?
Made sure the CPU & memory is not max'd at 100%
The server is not experience ephemeral port exhaustion
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Martyn LawsonNetwork AdministratorAuthor Commented:
In order to resolve this problem I implement hotfix KB2577795
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Martyn LawsonNetwork AdministratorAuthor Commented:
The other comments didn't not resolve the problem and I was forced to reboot the server every five days to avoid applications failure
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