Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

Microsoft Windows Performance Monitor, DNS, and "Unmatched Responses Received"

Posted on 2013-06-27
2
Medium Priority
?
850 Views
Last Modified: 2013-06-28
We've just replaced our aging, self-hosted, BIND DNS, public-facing physical name servers with Windows Server 2012 DNS virtual servers.  They're operating quite well.

Using Windows Performance Monitor, we're tracking the "UDP Queries Received/sec" and "UDP Response Sent/sec" which look good, peaking in the 300-400/sec range.

We also took a look a the "Unmatched Responses Received" statistic, currently at 427 after 10 days of uptime.  In comparison, this number is negligible compared to the successful response rate, but the interesting thing is that I've been unable to find any information to determine what an "Unmatched Response" is when related to DNS.

My searches to try to explain or define it have only found one or two mentions in passing, in discussions of DNS DDOS attacks, and in logging.  Can anyone fully define this for us, and explain what a sudden increase in "Unmatched Responses" might indicate?  Any URLs to plain, detailed information are certainly appreciated.

Thank you.

Dimarc67
Frederick, MD
0
Comment
Question by:Dimarc67
2 Comments
 
LVL 27

Accepted Solution

by:
DrDave242 earned 2000 total points
ID: 39286000
An unmatched response appears to be a DNS response packet sent to a machine that never issued a corresponding DNS query. This typically indicates that there's some source address spoofing going on somewhere, and a large number of these can indicate that a DNS amplification attack (a type of DDOS attack, as you said) is underway. This TechNet article does a good job of explaining how it all works.

I wouldn't worry about 427 unmatched responses over ten days, but if that counter suddenly spikes, you may be under attack.
0
 
LVL 4

Author Closing Comment

by:Dimarc67
ID: 39286042
Great response, Doc.  Thorough, corroborated, and specifically addresses the question.  Thanks much!
0

Featured Post

Who's Defending Your Organization from Threats?

Protecting against advanced threats requires an IT dream team – a well-oiled machine of people and solutions working together to defend your organization. Download our resource kit today to learn more about the tools you need to build you IT Dream Team!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

A safe way to clean winsxs folder from your windows server 2008 R2 editions
For anyone that has accidentally used newSID with Server 2008 R2 (like I did) and hasn't been able to get the server running again because you were unlucky (as I was) and had no backups - I was able to get things working by doing a Registry Hive rec…
This tutorial will walk an individual through the process of transferring the five major, necessary Active Directory Roles, commonly referred to as the FSMO roles from a Windows Server 2008 domain controller to a Windows Server 2012 domain controlle…
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…

564 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question