odbc.ucas.com lookup problem

[Mark Andrews]

In message <Prayer.1.3.3.1007201510560.10785 at hermes-2.csi.cam.ac.uk>, Chris Tho
mpson writes:
> We're having some local reports about delays resolving odbc.ucas.com.
> The problem is undoubtedly the response of "ns-lp.ucas.com", which
> seems to be some sort of load balancer, to AAAA queries. I get log
> entries from BIND like
> 
> Jul 20 14:35:12 koala.csi.cam.ac.uk named[4539]: [ID 873579 daemon.notice]
>   DNS format error from 194.80.160.250#53 resolving odbc.ucas.com/AAAA
>   for client 127.0.0.1#42869: invalid response
> 
> However, I haven't yet been able to work out exactly *what* is wrong
> with the response, as demonstrated by dig (say). Any ideas?

The load balance is incorrectly configured to serve ucas.com rather
than the zone delegated to it odbc.ucas.com.  i.e. the SOA record
at the end should be for odbc.ucas.com not ucas.com.

Mark

ucas.com.               172800  IN      NS      ns0.netcentral.co.uk.
ucas.com.               172800  IN      NS      ns1.netcentral.co.uk.
;; Received 83 bytes from 2001:503:a83e::2:30#53(a.gtld-servers.net) in 446 ms

odbc.ucas.com.          3600    IN      NS      ns-lp.ucas.com.
;; Received 115 bytes from 212.57.232.5#53(ns0.netcentral.co.uk) in 667 ms

ucas.com.               86400   IN      SOA     ucas.com. administrator.ucas.com. 998545544 28800 7200 604800 86400
;; Received 105 bytes from 195.188.99.250#53(ns-lp.ucas.com) in 327 ms

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org