unreliable DDNS updates by W2K clients

[Kevin Darcy]

In the "failing" scenario, Win2K only sent prerequisities ("PRE"), but no
update. This is Win2K's stupid way of "probing" whether or not a particular
name or RRset exists (why it doesn't just simply *query* the name, I have no
idea). The BIND server sent back a response indicating that the name or RRset
did or did not exist. But this wasn't an "error" or a "failure", since no
actual update was requested in the first place.

In the successful scenario, Win2K actually requested an update, along with the
prerequisites ("PRE/UPD"). Presumably the prerequisites were met and the update
was made, therefore the return code was different than the "failing" scenario.

There is no evidence here implicating BIND in this problem.


- Kevin

Linsenbardt, Duane L. wrote:

> Hello:
> We are experiencing intermittent DDNS registrations with Windows 2000,
> Service Pack 1, clients to BIND V8 running under Solaris V2.6.  Below are
> snippets from a failing and a successful trace.  Note difference between DNS
> response packet 55 in first snippet and 60 in the second.  Any assistance
> would be appreciated.
>
> -Duane
>
> Failing scenario:
> 50 DNS 0x7:Std Qry for d81000-41.ssd.jhuapl.edu. of type SOA on class INET
> addr.
> 51 DNS 0x7:Std Qry Resp. Auth. NS is ssd.jhuapl.edu. of type SOA on class
> INET addr. : Name does not exist
> 52 DNS 0x8:Std Qry for dallas.jhuapl.edu. of type Host Addr on class INET
> addr.
> 53 DNS 0x8:Std Qry Resp. Auth. NS is dallas.jhuapl.edu. of type Host Addr on
> class INET addr.
> 54 DNS 0x9:Dyn Upd PRE records to d81000-41.ssd.jhuapl.edu. of type
> Canonical name
> 55 DNS 0x9:Dyn Upd Resp.
>
> Successful scenario:
> 55 DNS 0x7:Std Qry for d81000-41.ssd.jhuapl.edu. of type SOA on class INET
> addr.
> 56 DNS 0x7:Std Qry Resp. Auth. NS is ssd.jhuapl.edu. of type SOA on class
> INET addr. : Name does not exist
> 57 DNS 0x8:Std Qry for dallas.jhuapl.edu. of type Host Addr on class INET
> addr.
> 58 DNS 0x8:Std Qry Resp. Auth. NS is dallas.jhuapl.edu. of type Host Addr on
> class INET addr.
> 59 DNS 0x9:Dyn Upd PRE records to d81000-41.ssd.jhuapl.edu. of type
> Canonical name
> 60 DNS 0x9:Dyn Upd Resp. : RR set that ought to exist, does not exist
> 61 DNS 0xA:Std Qry for d81000-41.ssd.jhuapl.edu. of type SOA on class INET
> addr.
> 62 DNS 0xA:Std Qry Resp. Auth. NS is ssd.jhuapl.edu. of type SOA on class
> INET addr. : Name does not exist
> 63 DNS 0xB:Std Qry for dallas.jhuapl.edu. of type Host Addr on class INET
> addr.
> 64 DNS 0xB:Std Qry Resp. Auth. NS is dallas.jhuapl.edu. of type Host Addr on
> class INET addr.
> 65 DNS 0xC:Dyn Upd PRE/UPD records to d81000-41.ssd.jhuapl.edu. of type
> Canonical name
> 66 DNS 0xC:Dyn Upd Resp.