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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi Sten,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Had tried with packet capture (WireShark), there is no request going out at all, so checking @ server side would not help, I suppose.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I referred book (<a href="http://read.pudn.com/downloads93/ebook/368831/IPv6ProtocolsImplementation/ipv6-advanced-protocols-implementation-the-morgan-kaufmann-series-in-networking.9780123704795.28081.pdf">IPv6
Advanced Protocols Implementation</a>), under section 3.4.7, authors mention about IPV6 reverse lookup, and say that link-local address should be ignored and a negative response is sent. I am not sure the same is implemented for forward lookup too.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">After trying out with dig/nslookup/host, I got confused how it is working there?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Glibc-resolver routines too use BIND, I suppose.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Alok<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">--Excerpts from the book--<o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="color:windowtext">Ignore Link-Local Addresses<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="color:windowtext">Listing 3-44<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">name6.c<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1443 static struct hostent *<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1444 _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp)<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1445 {<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1446 int n;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1447 struct hostent *hp;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1448 u_char c, *cp;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1449 char *bp;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1450 struct hostent hbuf;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1451 int na;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1453 static const char hex[] = "0123456789abcdef";<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1455 querybuf *buf;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1456 char qbuf[MAXDNAME+1];<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1457 char *hlist[2];<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1458 char *tld6[<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">] = { "ip6.arpa", "ip6.int", NULL };<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1459 char *tld4[<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">] = { "in-addr.arpa", NULL };<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1460 char **tld;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1461<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1463 /* XXX */<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1464 if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr))<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">1465 return NULL;<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:9.5pt;font-family:"Courier New";color:windowtext">name6.c<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="color:windowtext">1464–1465<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-family:"Arial","sans-serif";color:windowtext">If the given address is an IPv6 link-local address, a negative response is returned<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-family:"Arial","sans-serif";color:windowtext">without sending DNS queries. This check is actually meaningless, because all callers of<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-family:"Arial","sans-serif";color:windowtext">the function do the same check in this implementation</span></i><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext"> Sten Carlsen [mailto:stenc@s-carlsen.dk]
<br>
<b>Sent:</b> Monday, March 25, 2013 5:13 PM<br>
<b>To:</b> Alok Raj<br>
<b>Cc:</b> carlos@lacnic.net; Bryan Harris; bind-users@lists.isc.org<br>
<b>Subject:</b> Re: Dig for link-local<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt">One question is whether the server will listen and reply on all addresses or only on the global address?<br>
<br>
I suggest you look into the log file from the server, often there are good clues there.<br>
<br>
<o:p></o:p></p>
<div>
<p class="MsoNormal">On 25/03/13 10:19, Alok Raj wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<pre>Hi Guys,<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Basically I am trying to do the following:<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre> 1) If I use link-local ipv6 address (of domain controller) in my resolv.conf, my resolver routines (glibc 2.13) is not able to resolve a domain name to an ip address, though I am able to ping that link-<o:p></o:p></pre>
<pre> local ipv6 address.<o:p></o:p></pre>
<pre> 2) If I use global ipv6 address(of domain controller) in my resolv.conf, it works fine!<o:p></o:p></pre>
<pre> 3) So I wondered, how dig/nslookup/host- commands are able to get a name resolved when there is only one entry @ /etc/resolv.conf and that entry is an ipv6 link-local address of domain <o:p></o:p></pre>
<pre> controller.<o:p></o:p></pre>
<pre> 4) I have downloaded the BIND9 code and am looking into it.<o:p></o:p></pre>
<pre> 5) Similarly if I ping using ping6, my domain name gets resolved if global ipv6 address in resolv.conf; not resolved if link-local ipv6 address.<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>If my doubts sound trivial, I am sorry, I am very new to the above concepts.<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Thanks,<o:p></o:p></pre>
<pre>Alok<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre><o:p> </o:p></pre>
<pre><o:p> </o:p></pre>
<pre>-----Original Message-----<o:p></o:p></pre>
<pre>From: <a href="mailto:bind-users-bounces+alok.raj=spanservices.com@lists.isc.org">bind-users-bounces+alok.raj=spanservices.com@lists.isc.org</a> [<a href="mailto:bind-users-bounces+alok.raj=spanservices.com@lists.isc.org">mailto:bind-users-bounces+alok.raj=spanservices.com@lists.isc.org</a>] On Behalf Of Carlos M. Martinez<o:p></o:p></pre>
<pre>Sent: Friday, March 22, 2013 9:57 PM<o:p></o:p></pre>
<pre>To: Bryan Harris<o:p></o:p></pre>
<pre>Cc: <a href="mailto:bind-users@lists.isc.org">bind-users@lists.isc.org</a><o:p></o:p></pre>
<pre>Subject: Re: Dig for link-local<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Transport has nothing to do with content in DNS. If your client asks for an AAAA record it will get the appropriate answer according to the zone's records (a value or an error condition) regardless on whether the query was made over IPv6 or IPv4.<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>That said, you can 'hack' around this expected behavior (see 'no AAAA on<o:p></o:p></pre>
<pre>ipv4') in order to help hosts with broken IPv6 connectivity, but you have to enable it.<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>regards,<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>~Carlos<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>On 3/22/13 1:19 PM, Bryan Harris wrote:<o:p></o:p></pre>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<pre>Hello,<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>On Mar 22, 2013, at 12:13 PM, Kevin Darcy <a href="mailto:kcd@chrysler.com"><kcd@chrysler.com></a> wrote:<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<pre>I'm not sure what you're asking, exactly. Are you surprised that named would respond on an IPv6 link-local address if configured with "listen-on-v6 { any; };"? <o:p></o:p></pre>
</blockquote>
<pre><o:p> </o:p></pre>
<pre>Can an ipv4-only server give an ipv6 address as part of an overall <o:p></o:p></pre>
<pre>answer to a dig? E.g. Our servers recurse to get outside addresses, <o:p></o:p></pre>
<pre>and when I query for <a href="http://www.google.com">www.google.com</a> one of the addresses is ip6<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Bryan<o:p></o:p></pre>
<pre>_______________________________________________<o:p></o:p></pre>
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<p class="MsoNormal"><br>
<br>
<o:p></o:p></p>
<pre>-- <o:p></o:p></pre>
<pre>Best regards<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Sten Carlsen<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>No improvements come from shouting:<o:p></o:p></pre>
<pre> "MALE BOVINE MANURE!!!"<o:p></o:p></pre>
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