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"ANY". That NS record tells *the*world* (not just your ISP) that
they can come to your nameserver to resolve names in the zone.<br>
<br>
It wouldn't be much a failover strategy if you were relying on your
ISP's nameservers to somehow "proxy" the queries over to you, when
they're down. <br>
<br>
Open up inbound destination port 53 TCP/UDP (for queries) and
outbound source port 53 TCP/UDP (for responses). The destination
port outbound will be the same as the source port inbound, for a
given DNS transaction, if your firewalls are stateful enough to keep
track of such things.<br>
<br>
- Kevin<br>
<br>
On 9/18/2011 12:01 PM, babu dheen wrote:
<blockquote
cite="mid:1316361662.97636.YahooMailNeo@web137302.mail.in.yahoo.com"
type="cite">
<div style="color: rgb(0, 0, 0); background-color: rgb(255, 255,
255); font-family: times new roman,new york,times,serif;
font-size: 12pt;">
<div><span>Hi,</span></div>
<div><span> Once i delegated NS record in my ISP name server to
my company name server for mail.myoffice.com website as
below. Do i need to allow DNS port from ANY(INTERNET) to my
DNS server in firewall or i just need to allow DNS traffic
only from ISP DNS server</span></div>
<div><span></span> </div>
<div><span>ISP DNS server configuration</span></div>
<div><span></span> </div>
<div><span>mycompany-dns-server-ip IN<span class="tab"> A
10.10.10.10</span></span></div>
<div><span>mail.myoffice.com<span class="tab"> <span
class="tab"> IN<span class="tab"> NS<span
class="tab"> <mycompany dns server ip></span></span></span></span></span></div>
<div> </div>
<div> </div>
<div>Regards</div>
<div>Papdheen M<br>
</div>
<div style="font-family: times new roman,new york,times,serif;
font-size: 12pt;">
<div style="font-family: times new roman,new york,times,serif;
font-size: 12pt;"><font face="Arial" size="2"><b><span
style="font-weight: bold;">From:</span></b> Kevin
Darcy <a class="moz-txt-link-rfc2396E" href="mailto:kcd@chrysler.com"><kcd@chrysler.com></a><br>
<b><span style="font-weight: bold;">To:</span></b>
<a class="moz-txt-link-abbreviated" href="mailto:bind-users@lists.isc.org">bind-users@lists.isc.org</a><br>
<b><span style="font-weight: bold;">Sent:</span></b>
Sunday, 18 September 2011 5:09 PM<br>
<b><span style="font-weight: bold;">Subject:</span></b>
Re: Query regarding NS record<br>
</font><br>
<meta content="off" http-equiv="x-dns-prefetch-control">
<div id="yiv2026477857">
<title></title>
Are you talking about recursive clients failing over?<br>
<br>
Or other nameservers trying to talk to yours,
non-recursively?<br>
<br>
Recursive clients don't use NS records at all and you need
to approach the failover problem in a completely different
way (e.g. relying on the client failing over from one
resolver IP address to another, or implementing an Anycast
solution).<br>
<br>
If you're talking about nameserver-to-nameserver traffic,
then just publish multiple NS records for the relevant
zone(s) and the nameserver-selection algorithm embedded in
every known iterative-resolver implementation will take
care of the load-balancing and failover; to summarize,
faster-responding nameservers will be chosen over
slower-responding ones.<br>
<br>
- Kevin<br>
<br>
On 9/16/2011 11:17 AM, babu dheen wrote:
<blockquote type="cite">
<div style="color: rgb(0, 0, 0); font-family: times new
roman,new york,times,serif; font-size: 12pt;
background-color: rgb(255, 255, 255);">
<div>Hi,</div>
<div> Can anyone let me know how i can resolve the
below requirement.</div>
<div> </div>
<div> </div>
<div>Requirement:</div>
<div> </div>
<div>We have two offices. One is main office and
another one is remote branch office. Now my company
client requirement is that if main office DNS server
is not reachable, all DNS query should be sent to
branch office DNS server. How this can be acheived
using BIND?</div>
<div> </div>
<div>For example, my company mail website is;
mail.mycompany.com which is pointed as below in ISP
name server.</div>
<div> </div>
<div>mail.mycompany.com<span class="yiv2026477857tab"> <span
class="yiv2026477857tab"> IN<span
class="yiv2026477857tab"> NS<span
class="yiv2026477857tab"> ns1.mainoffice.com</span></span></span></span></div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab">mail.mycompany.com<span
class="yiv2026477857tab"> <span
class="yiv2026477857tab"> IN<span
class="yiv2026477857tab"> NS<span
class="yiv2026477857tab"> ns1.branceoffice.com</span></span></span></span></span></span></span></span></div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"></span></span></span></span></span></span></span></span> </div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"> Is the
above record is correct or not?</span></span></span></span></span></span></span></span></div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"></span></span></span></span></span></span></span></span> </div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"> Please
suggest.</span></span></span></span></span></span></span></span></div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"></span></span></span></span></span></span></span></span> </div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab">Regards</span></span></span></span></span></span></span></span></div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab">papdheen M</span></span></span></span></span></span></span></span></div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"></span></span></span></span> </div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"></span></span></span></span> </div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"> </span></span></span></span></div>
<div><span class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"><span
class="yiv2026477857tab"></span></span></span></span> </div>
</div>
<pre><fieldset class="yiv2026477857mimeAttachmentHeader"></fieldset>
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