Tuning issue with false positive

Unanswered Question
Jul 29th, 2009
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One of my clients moved two of their email devices to a DMZ. The both produce alerts on the mass mailing worm alert. Before they were moved to the DMZ, you would see the alert and it would have a source and destination IP. Now it only has the destination IP address of where the device is sending email to. Since the MARS does not pick up the devices new IP address, I cannot false positive tune these alerts out. How would I go about fixing this issue?

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a-vazquez Tue, 08/04/2009 - 13:39
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When the IDS mistakenly thinks that normal traffic is malicious then false positives happen To reduce them you have to fine tune the system by letting it know what normal traffic means on your network.


Cisco has provided some great guidance on how to reduce false positives here:

http://www.cisco.com/en/US/products/ps6241/products_user_guide_chapter09186a008072f396.html#wp1030968


pmccubbin Wed, 08/05/2009 - 04:25
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I agree 100% with Anthony. You must tune the IDS and reduce the false positives at the source, not try to tune them on MARS.


A "5" from NYC.

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