Solved

Malformed packets from 127.0.0.1 every ~62.5 seconds

Posted on 2016-09-19
4
60 Views
Last Modified: 2016-10-09
On a 2008r2 Domain Controller, with Exchange Exchange 2010 installed (I am very aware that this is not optimal, but when you inherit a client network...)

Event ID 5502 repeated every ~62.5 seconds with the text

The DNS server received a bad TCP-based DNS message from 127.0.0.1.  The packet was rejected or ignored. The event data contains the DNS packet.

Open in new window


As Wireshark is unable to capture from loopback, I used RawCap  to capture traffic on the loopback interface for several minutes, and then opened up the capture in WireShark, which shows a repeated malformed packet as per the attached.

While I have stopped the event from showing by changing DNS event logging from "All events" to "Errors and warnings", I am interested in why might be causing this, especially with the frequency of recurrence...
0
Comment
Question by:ArneLovius
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
4 Comments
 
LVL 62

Expert Comment

by:gheist
ID: 41806861
Is it some montiring script checking DNS is up with TCP? like nagios/zabbix whatever?
0
 
LVL 37

Author Comment

by:ArneLovius
ID: 41806989
I haven't found anything obviously scheduled, and as the source is 127.0.0.1 it has to be local to the server.

The cycle time of ~62.5 seconds makes me think that its an internal process rather than a scheduled one, but I'm quite happy to admit that I;m stumped by it :-)
0
 
LVL 62

Accepted Solution

by:
gheist earned 500 total points (awarded by participants)
ID: 41807346
nslookup timeout is 2s. so something sleeps 1min, then does nslookup then sleeps again.
0
 
LVL 62

Expert Comment

by:gheist
ID: 41835700
Hard to guess better.
0

Featured Post

Forrester Webinar: xMatters Delivers 261% ROI

Guest speaker Dean Davison, Forrester Principal Consultant, explains how a Fortune 500 communication company using xMatters found these results: Achieved a 261% ROI, Experienced $753,280 in net present value benefits over 3 years and Reduced MTTR by 91% for tier 1 incidents.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Not able to use trace mode with dig 1 28
active directory, exhange 12 62
Change subnet - effects on server 14 38
List Boot time of several computers 4 16
BIND is the most widely used Name Server. A Name Server is the one that translates a site name to it's IP address. There is a new bug in BIND (https://kb.isc.org/article/AA-01272), affecting all versions of BIND 9 from BIND 9.1.0 (inclusive) thro…
Resolve DNS query failed errors for Exchange
This tutorial will show how to configure a new Backup Exec 2012 server and move an existing database to that server with the use of the BEUtility. Install Backup Exec 2012 on the new server and apply all of the latest hotfixes and service packs. The…
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 to another domain controller. Log onto the new domain controller with a user account t…

734 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