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

[Xander D Harkness]

Robert McKay wrote:

>On Thu, 18 Jul 2002, Xander D Harkness wrote:
>
>>Having set the IP addresses correctly there are a couple of domains that 
>>are experiencing difficulty resolving the mx records for the domain 
>>mactelecom.com.
>>
>
>>Now I know that there are many name servers that can correctly resolve 
>>the mx records, the fact that there are some that cannot is my fault and 
>>my responsability to resolve (So I have been toild by those that pay me ;-)
>>
>
>>The errors that are returned from the mail servers are failure to 
>>resolve MX records.  These nameservers seem to resolve other domains 
>>okay hosted on the same nameservers (harkness.co.uk for example).  Is 
>>there something stupid I have done (Just like the IPs :-)
>>
>
>>In addition would other people work with the owners of the other 
>>nameservers or consider it their problem - they will have to sort it out?
>>
>
>>Two of these domains that are having difficulty are alcatel.be and cofino.be
>>
>
>>alcatel has four name servers (I am guessing that these are the servers 
>>used by their mail servers)
>>;; ANSWER SECTION:
>>alcatel.be.             10624   IN      NS      ns.alcatel.be.
>>alcatel.be.             10624   IN      NS      ns.alcatel.co.uk.
>>alcatel.be.             10624   IN      NS      secdns.eunet.be.
>>alcatel.be.             10624   IN      NS      ns.alcanet.no.
>>
>>####################################
>>by querying using dig @ns.alcatel.be mactelecom.com mx
>>
>
>>the first says no name servers could be found - even if I put +trace on 
>>the end.  In short it looks dead.
>>
>
>ns.alcatel.be appears to be down.. it doesn't respond to any queries. None
>of that really proves anything though. We don't even know if the
>mailservers use those nameservers at all.. there's no particular reason
>why they should - those are external nameservers and arguably should even
>be configured to deny all recursive lookups (they don't appear to be
>though).
>
>Your assertion that harkness.co.uk is served from the same nameservers
>appears to be misleading. harkness.co.uk is served from:
>
>DAVROS.WILDTHORN.COM              213.48.46.196
>SPITFIRE.WILDTHORN.COM            213.48.46.206
>
>ns1/ns2.harkness also serve as backup NS however in this case
>ns1.harkness.co.uk (the broken one) is only 1/4th of your rotation instead
>of 1/2.
>
>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.

>
>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.

>
>
>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   

Kind regards
Xander





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