[Snort-users] named AXFR's anomoly?

Jason Haar Jason.Haar at ...294...
Mon Nov 20 15:03:18 EST 2000

I'm running bind 8.2.2-p5 (p7 now of course) and last week snort picked up
an IP address attempting a AXFR  of our DNS data that wasn't our secondary.
Just cause I was bored I cross-checked it against named's syslog entries and
lo and behold! no corresponding "unapproved AXFR " entry!

I then logged into a ISP and attempted a AXFR myself - and was blocked - and
that was logged - so everything looks like it's working to me.

Looking some more, I see that there is an entry from named of:

named[15237]: unapproved update from [x.x.x.x].1242 for xxx

The timestamp matches the entry in snort for the AXFR - but the source port
number is 1243!

[From the contents of the packet I can tell it's an employee running
Windows2000 which has "update DNS" turned on - so it's no hacker].

So, should IDS212 match a DDNS packet as a AXFR, and why is the source port
number a few  off that reported by named? 

Does M$ DDS do some kind of 'update DNS and then AXFR DNS for "network
neighbourhood"' kind of thing?


Jason Haar

Unix/Special Projects, Trimble NZ
Phone: +64 3 9635 377 Fax: +64 3 9635 417

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