[Gllug] now DNS difficulties :-) strange SMTP stuff

[Robert McKay]

On Fri, 19 Jul 2002, Xander D Harkness wrote:

> Robert McKay wrote:

> >Whereas mactelecom.com is served from:
> >NS1.HARKNESS.CO.UK           80.234.135.41 <-- this does not respond.

> I have not had any downtime on these and I have no idea why you could 
> not reach it.

It's not responding.

If you are able to query it maybe you have some firewall rules which are
allowing you to connect while denying the rest of the world. Whatever the
reason, I've tried from several places and it doesn't respond.

> >NS2.HARKNESS.CO.UK           80.234.135.42

> >I notice those appear to be tele2.co.uk IPs.. are they wireless?

> I also have had difficulties with cpicountrywide.co.uk which has its 
> domain hosted by these and name servers in another subnet.  It is not 
> that the name servers are unreachable, just some name servers have 
> difficulty querying them.  Some thing that I cannot explain.

There seem to be additional issues with cpicountrywide.co.uk:

Almost all your nameservers are running different versions of the zone.

ns2.harkness.co.uk has 2001092652 which I presume to be the "correct"
serial as it is the highest number. It is the only nameserver with this
serial. (ns1.harkness.co.uk does not respond.)

> cpicountrywide.co.uk.
Server:  ns2.harkness.co.uk
Address:  80.234.135.42

cpicountrywide.co.uk
        origin = davros.wildthorn.com
        mail addr = postmaster.dgh.co.uk
        serial = 2001092652
        refresh = 25000 (6h56m40s)
        retry   = 10800 (3H)
        expire  = 604800 (1W)
        minimum ttl = 86400 (1D)
cpicountrywide.co.uk    nameserver = ns1.nanbudo.co.uk
cpicountrywide.co.uk    nameserver = ns1.harkness.co.uk
cpicountrywide.co.uk    nameserver = ns2.harkness.co.uk
cpicountrywide.co.uk    nameserver = davros.wildthorn.com
cpicountrywide.co.uk    nameserver = spitfire.wildthorn.com

ns1.nanbudo.co.uk has a serial number of 4 and is the only nameserver with
that serial. This zone only specifies three nameservers,
ns1.nanbudo.co.uk, ns2.harkness.co.uk and ns1.harkness.co.uk (which does
not respond).

> cpicountrywide.co.uk.
Server:  ns1.nanbudo.co.uk
Address:  217.34.111.253

cpicountrywide.co.uk    internet address = 217.34.111.253
cpicountrywide.co.uk
        origin = cpicountrywide.co.uk
        mail addr = info.cpicountrywide.co.uk.cpicountrywide.co.uk
        serial = 4
        refresh = 28800 (8H)
        retry   = 7200 (2H)
        expire  = 604800 (1W)
        minimum ttl = 86400 (1D)
cpicountrywide.co.uk    nameserver = ns1.nanbudo.co.uk
cpicountrywide.co.uk    nameserver = ns1.harkness.co.uk
cpicountrywide.co.uk    nameserver = ns2.harkness.co.uk

davros.wildthorn.com and spitfire.wildthorn.com both agree that the serial
number is 2001092651 (ie: one less than ns2.harkness.co.uk's serial which
was 2001092652). You'll also note that this zone only has two nameservers,
devros and spitfire.

Server:  davros.wildthorn.com
Address:  213.48.46.196

cpicountrywide.co.uk
        origin = davros.wildthorn.com
        mail addr = postmaster.dgh.co.uk
        serial = 2001092651
        refresh = 25000 (6h56m40s)
        retry   = 10800 (3H)
        expire  = 604800 (1W)
        minimum ttl = 86400 (1D)
cpicountrywide.co.uk    nameserver = spitfire.wildthorn.com
cpicountrywide.co.uk    nameserver = davros.wildthorn.com

> cpicountrywide.co.uk.
Server:  spitfire.wildthorn.com
Address:  213.48.46.206

cpicountrywide.co.uk
        origin = davros.wildthorn.com
        mail addr = postmaster.dgh.co.uk
        serial = 2001092651
        refresh = 25000 (6h56m40s)
        retry   = 10800 (3H)
        expire  = 604800 (1W)
        minimum ttl = 86400 (1D)
cpicountrywide.co.uk    nameserver = spitfire.wildthorn.com
cpicountrywide.co.uk    nameserver = davros.wildthorn.com

All the nameservers are listed in the UK TLD servers so clients will
randomly select one of these nameservers to query first. Since all the
nameservers have a different idea of what the nameservers for the domain
should be, resolvers will get stuck on which ever nameserver group they
are returned first;

It might be in this situation that you would have timeout problems similar
to the ones with mactelecom.com due to only two working nameservers
(ns1.nanbudo.co.uk, ns2.harkness.co.uk) and one of them with a possibly
suspect internet connection (ns2.harkness.co.uk).

In any case this domain is severely buggered. :)

> >17 packets transmitted, 13 packets received, 23% packet loss
> >round-trip min/avg/max = 188.5/358.4/1218.6 ms

> >That's my ping stats from 80.234.135.42 .. not exactly ideal for your only
> >working nameserver. I suspect that's likely the cause.. Only one
> >nameserver working and it has 23% packet loss. :/

> That seems unusually high, over a four minute period I would expect 
> about a 2% packet loss   

It seems much better now.. I retried it and am not getting any packet
loss. However I _was_ getting 23% packet loss before and that would cause
problems resolving mactelecom.com, especually since ns1.harkness.co.uk is
not responding.

Regards,

Robert McKay.



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