[nSLUG] Static IP woes

Dop Ganger nslug at fop.ns.ca
Wed Sep 21 10:00:03 ADT 2005


On Tue, 20 Sep 2005, Donald Teed wrote:

> Here is a basic DNS test. Whip up a web browser.
> The IP for www.imp.ca <http://www.imp.ca> is
> 142.176.189.229<http://142.176.189.229>, so
> you should be able to see http://142.176.189.229
> If that IP works to load the page, but using www.imp.ca <http://www.imp.ca>does
> not work, then you have a DNS issue, not a router issue.

Unfortunately... no. If you go to http://142.176.189.229 you'll just get 
an immediate redirect to http://www.impsolutions.com, and if DNS is broken 
it will also result in an error.

You can, however, go to http://131.162.200.72 and compare it to 
http://www.acadiau.ca instead... :-)

> It has been awhile since I looked at this, but I believe
> there is also a UDP requirement for DNS - possibly port 53 again.

Yes. DNS will default to UDP port 53, TCP is only used for requests that 
will probably return long answers (usually zone transfers), and if the UDP 
query results in a packet too large error the request will (or possibly 
should, I don't recall the RFC syntax) be retried as a TCP request 
instead. So, if the slackware box is serving DNS zones the router should 
be set up to forward both TCP and UDP packets on port 53 to the internal 
server. If the DNS is cacheing only (and the original email wasn't clear 
on this point) a NAT connection is sufficient and no port forwarding 
should be done.

Cheers... Dop.

!DSPAM:43315993132117530013364!




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