Viewing DNS Caching server's cache under Bind 9

Joe Kattner joe.kattner at
Tue Oct 9 12:14:39 UTC 2001

BIND 9 uses rndc for control. 'rndc dumpdb' dumps the cache to


-----Original Message-----
From: Josh [mailto:thechile at]
Sent: Monday, October 08, 2001 6:26 PM
To: comp-protocols-dns-bind at
Subject: Viewing DNS Caching server's cache under Bind 9


I have a simple caching server that i think is working ok but i would like
to see its current cache db in memory. I have seen people say use "ndc
named_dump.db" or something like that but i can't find ndc in my bind 9
installation so i was wondering if there is a new/different way of doing

Thanks for reading,

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Date: Tue, 9 Oct 2001 15:41:23 +0100
From: James Raftery <james-bind-users at>
To: bind-users at
Subject: DNS header format for Query requests
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I'm trying to diagnose a problem with a piece of equipment that
seems to be sending badly formed DNS queries. I need to get an accurate
description of the Header format for a Query request but the maze
of RFCs is melting my brain.

Is the Header format in RFC1035 still correct and complete for
Opcode 0 (Query) requests? I know it's been amended for other Opcodes, 
Update for instance.

Specifically tcpdump is seeing Headers with the fourth byte set to
0x40: which mean the first ``Z'' bit is set. Have any of the Z bits
been defined for Query requests?

James Raftery (JBR54)
  "It's somewhere in the Red Hat district"  --  A network engineer's
   freudian slip when talking about Amsterdam's nightlife at RIPE 38.

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