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Is PRTG producing network traffic on UDP port 137?

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I did a fresh install of Windows 2003 server and installed PRTG ver.8.1.0.1621. On my firewall, I am seeing lots of UDP port137 traffic from the PRTG server and going to external IPs on the Internet. PRTG is configured to monitor a mirrored port on the switch which is connected to the internal interface of my firewall. It is also configured to monitor certain ports on my switch via SNMP. Why is this?

monitor prtg udp137

Created on Oct 4, 2010 2:04:18 PM

Last change on Oct 15, 2010 2:35:14 PM by Daniel Zobel [Product Manager]



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Accepted Answer

Votes:

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Hallo,

do you use Packet Sniffing and TopLists? If so, the traffic you see on port 137 are DNS requests so that PRTG can translate the IPs in the TopLists to DNS names.

see

http://www.iss.net/security_center/advice/Exploits/Ports/137/default.htm

Created on Oct 7, 2010 8:30:18 AM by Aurelio Lombardi [Paessler Support]




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