In the DMM GUI all DMPs are reported as down.
DMPs are not showing any updated content.
DMPs and DMMs are otherwise reachable on IP Network side.
How to identify the symptom:
DMP itself will report an HTTP status: 500 Unknown Exception: peer not authenticated
When you access the DMP using a browser and check for the certificate it will show a certificate with an expiration date of 2/24/2012. This is tracked under Bug ID CSCty22538.
There is a field notice posted on this issue - FN # 63496. Here is the link for this field notice:
The field notice has listed affected versions of DMPs.
The field notice has steps to get the patch on DMM as a Work-Around.
The field notice lists a Readme link which gives steps for installing the patch.
The actual issue itself will be addressed in a future software release when the Certificate Expiration issue will be fixed.
Other Additional Questions about the patch:
What are the implications of using the patch in terms of Security - will the communication still be secure?
The communication between DMP and DMM will continue to be secure. The patch will ignore the certificate expiration message.