A while ago, I had three websites reported to me that people were having 
issues accessing.  Then, as I wrote this email at the time, they appeared 
to stop working again.

They were:

    www.parkersteel.co.uk

    www.acas.org.uk

    www.icaew.com

All appear to have DNS hosting at star.co.uk.

Today, I have had a report that a site cannot email here.  The mail logs 
show that we are refusing the messages because of a failure to perform DNS 
resolution on the sender domain, which is sourcebioscience.com.  Again, 
this is hosted at star.co.uk, and testing parkersteel again I see the same 
issue has returned.

When I attempt a resolve locally:

> dig www.icaew.com

...
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 23885
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.icaew.com.                 IN      A


But:

> dig +trace www.icaew.com

; <<>> DiG 9.6.-ESV-R3 <<>> +trace www.icaew.com
;; global options: +cmd
.                       455780  IN      NS      h.root-servers.net.
.                       455780  IN      NS      d.root-servers.net.
.                       455780  IN      NS      a.root-servers.net.
.                       455780  IN      NS      j.root-servers.net.
.                       455780  IN      NS      k.root-servers.net.
.                       455780  IN      NS      m.root-servers.net.
.                       455780  IN      NS      l.root-servers.net.
.                       455780  IN      NS      i.root-servers.net.
.                       455780  IN      NS      e.root-servers.net.
.                       455780  IN      NS      f.root-servers.net.
.                       455780  IN      NS      b.root-servers.net.
.                       455780  IN      NS      c.root-servers.net.
.                       455780  IN      NS      g.root-servers.net.
;; Received 496 bytes from 130.159.248.50#53(130.159.248.50) in 4 ms

com.                    172800  IN      NS      g.gtld-servers.net.
com.                    172800  IN      NS      c.gtld-servers.net.
com.                    172800  IN      NS      m.gtld-servers.net.
com.                    172800  IN      NS      f.gtld-servers.net.
com.                    172800  IN      NS      l.gtld-servers.net.
com.                    172800  IN      NS      b.gtld-servers.net.
com.                    172800  IN      NS      i.gtld-servers.net.
com.                    172800  IN      NS      j.gtld-servers.net.
com.                    172800  IN      NS      d.gtld-servers.net.
com.                    172800  IN      NS      k.gtld-servers.net.
com.                    172800  IN      NS      e.gtld-servers.net.
com.                    172800  IN      NS      h.gtld-servers.net.
com.                    172800  IN      NS      a.gtld-servers.net.
;; Received 503 bytes from 192.36.148.17#53(i.root-servers.net) in 100 ms

icaew.com.              172800  IN      NS      dns0.star.co.uk.
icaew.com.              172800  IN      NS      dns1.star.co.uk.
;; Received 79 bytes from 192.42.93.30#53(g.gtld-servers.net) in 156 ms

www.icaew.com.          9000    IN      A       80.168.4.227
;; Received 47 bytes from 195.8.69.36#53(dns1.star.co.uk) in 11 ms

Same successful result if I use the Google resolvers, and squish.net finds 
OK too.

Can anyone suggest a reason for the resolver behaviour?  Well, OK, the 
real question is, could it be a local issue or something ISP-side that 
Star/etc need to address?

Jethro.


.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
Jethro R Binks, Network Manager,
Information Services Directorate, University Of Strathclyde, Glasgow, UK

The University of Strathclyde is a charitable body, registered in
Scotland, number SC015263.