[nSLUG] Static IP woes
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
> 184.108.40.206<http://220.127.116.11>, so
> you should be able to see http://18.104.22.168
> 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://22.214.171.124 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://126.96.36.199 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.
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