Hi ,<div><br></div><div>I am not exactly sure of this.</div><div>But as far as i know, prefix length is managed by router advertisements i.e., RA .</div><div><br></div><div>If you use prefix delegation there is a provision for sending prefix length i think.</div>
<div><br></div><div><p class="MsoNormal" style="margin-top:2.25pt"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">Please refer to the link</span></p>
<p class="MsoNormal" style="margin-top:2.25pt"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black"> </span></p>
<p class="MsoNormal" style="margin-top:2.25pt"><a href="http://docs.oracle.com/cd/E19082-01/819-3000/geflo/index.html">http://docs.oracle.com/cd/E19082-01/819-3000/geflo/index.html</a></p>
<p class="MsoNormal" style="margin-top:2.25pt"><b><span style="font-size:16.5pt;font-family:"Arial","sans-serif";color:black"> </span></b></p>
<p class="MsoNormal" style="margin-top:2.25pt"><b><span style="font-size:16.5pt;font-family:"Arial","sans-serif";color:black">Differences between DHCPv4 and
DHCPv6</span></b></p>
<p class="MsoNormal" style="margin-top:1.5pt"><a name="indexterm-1410"></a><a name="indexterm-1411"></a><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222">The two major differences between
DHCPv4 and DHCPv6 are the following:</span></p>
<p class="MsoNormal" style="margin-left:19.5pt"><span style="font-size:10.0pt;font-family:Symbol;color:#222222"><span style>·<span style="font:7.0pt "Times New Roman"">
</span></span></span><b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222">The administrative model</span></b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222"></span></p>
<p class="MsoNormal" style="margin-left:39.0pt"><span style="font-size:10.0pt;font-family:"Courier New";color:#222222"><span style>o<span style="font:7.0pt "Times New Roman""> </span></span></span><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222">DHCPv4–The
administrator enables DHCP for each interface. Administration is on a
per-logical interface basis.</span></p>
<p class="MsoNormal" style="margin-left:39.0pt"><span style="font-size:10.0pt;font-family:"Courier New";color:#222222"><span style>o<span style="font:7.0pt "Times New Roman""> </span></span></span><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222">DHCPv6–Explicit
configuration is not necessary. This protocol is enabled on a given physical
interface.</span></p>
<p class="MsoNormal" style="margin-left:19.5pt"><span style="font-size:10.0pt;font-family:Symbol;color:#222222"><span style>·<span style="font:7.0pt "Times New Roman"">
</span></span></span><b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222">Protocol details</span></b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222"></span></p>
<p class="MsoNormal" style="margin-left:39.0pt"><a name=""></a><span style="font-size:10.0pt;font-family:"Courier New";color:#222222"><span style>o<span style="font:7.0pt "Times New Roman"">
</span></span></span><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222">DHCPv4–The DHCP server supplies the subnet mask for each
address. A hostname option sets the system-wide node name.</span></p>
<p class="MsoNormal" style="margin-left:39.0pt"><span style="font-size:10.0pt;font-family:"Courier New";color:#222222"><span style>o<span style="font:7.0pt "Times New Roman""> </span></span></span><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#222222">DHCPv6–The
subnet mask is supplied by Router Advertisements, not the DHCPv6 server. There
is no DHCPv6 hostname option.</span></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">It clearly mentions that DHCPv6 doesn’t handle subnet mask
(prefix length) management.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><a href="http://tools.ietf.org/html/rfc4861#section-4.2">http://tools.ietf.org/html/rfc4861#section-4.2</a></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Also refer this.</p>
<p class="MsoNormal">In router advertisement ,M bit should be set for DHCPv6.</p>
<p class="MsoNormal"> </p>
<h3 style><a name="section-4.2"></a><span style><a href="http://tools.ietf.org/html/rfc4861#section-4.2"><span style="font-size:12.0pt;font-family:"Courier New";color:black">4.2</span></a></span><span style="font-size:12.0pt;font-family:"Courier New";color:black">. Router Advertisement Message Format</span></h3>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> Routers send out Router Advertisement messages periodically, or in</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> response to Router Solicitations.</span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> 0 1 2 3</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1</span></pre><pre style><span style="font-size:12.0pt;color:black"> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> | Type | Code | Checksum |</span></pre><pre style><span style="font-size:12.0pt;color:black"> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> | Cur Hop Limit |M|O| Reserved | Router Lifetime |</span></pre><pre style><span style="font-size:12.0pt;color:black"> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> | Reachable Time |</span></pre><pre style><span style="font-size:12.0pt;color:black"> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> | Retrans Timer |</span></pre><pre style><span style="font-size:12.0pt;color:black"> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> | Options ...</span></pre><pre style><span style="font-size:12.0pt;color:black"> +-+-+-+-+-+-+-+-+-+-+-+-</span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre>
<pre style><span style="font-size:12.0pt;color:black"> IP Fields:</span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> Source Address</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> MUST be the link-local address assigned to the</span></pre><pre style><span style="font-size:12.0pt;color:black"> interface from which this message is sent.</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span class="grey"><span style="font-size:12.0pt;color:#777777">Narten, et al. Standards Track [Page 19]</span></span><span style="font-size:12.0pt;color:black"></span></pre>
<pre style><a name="page-20" id="page-20"></a><a href="http://tools.ietf.org/html/rfc4861#page-20"><span style="font-size:12.0pt;color:white"> </span></a><span style="font-size:12.0pt;color:black"></span></pre><pre style>
<span class="grey"><span style="font-size:12.0pt;color:#777777"><a href="http://tools.ietf.org/html/rfc4861"><span style="color:#777777">RFC 4861</span></a> Neighbor Discovery in IPv6 September 2007</span></span><span style="font-size:12.0pt;color:black"></span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> Destination Address</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> Typically the Source Address of an invoking Router</span></pre><pre style><span style="font-size:12.0pt;color:black"> Solicitation or the all-nodes multicast address.</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> Hop Limit 255</span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre>
<pre style><span style="font-size:12.0pt;color:black"> ICMP Fields:</span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> Type 134</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> Code 0</span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre>
<pre style><span style="font-size:12.0pt;color:black"> Checksum The ICMP checksum. See [<a href="http://tools.ietf.org/html/rfc4861#ref-ICMPv6" title=""Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification"">ICMPv6</a>].</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> Cur Hop Limit 8-bit unsigned integer. The default value that</span></pre><pre style><span style="font-size:12.0pt;color:black"> should be placed in the Hop Count field of the IP</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> header for outgoing IP packets. A value of zero</span></pre><pre style><span style="font-size:12.0pt;color:black"> means unspecified (by this router).</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> </span><span style="font-size:12.0pt;color:red">M 1-bit "Managed address configuration" flag. When</span></pre>
<pre style><span style="font-size:12.0pt;color:red"> set, it indicates that addresses are available via</span></pre><pre style><span style="font-size:12.0pt;color:red"> Dynamic Host Configuration Protocol [<a href="http://tools.ietf.org/html/rfc4861#ref-DHCPv6" title=""Dynamic Host Configuration Protocol for IPv6 (DHCPv6)""><span style="color:red">DHCPv6</span></a>].</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> If the M flag is set, the O flag is redundant and</span></pre><pre style><span style="font-size:12.0pt;color:black"> can be ignored because DHCPv6 will return all</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> available configuration information.</span></pre><pre style><span style="font-size:12.0pt;color:black"> </span></pre><pre style><span style="font-size:12.0pt;color:black"> O 1-bit "Other configuration" flag. When set, it</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> indicates that other configuration information is</span></pre><pre style><span style="font-size:12.0pt;color:black"> available via DHCPv6. Examples of such information</span></pre>
<pre style><span style="font-size:12.0pt;color:black"> are DNS-related information or information on other</span></pre><pre style><span style="font-size:12.0pt;color:black"> servers within the network.</span></pre>
<p class="MsoNormal"> </p><br><div class="gmail_quote">On Wed, May 2, 2012 at 6:03 PM, MAYER Hans <span dir="ltr"><<a href="mailto:mayer@iiasa.ac.at" target="_blank">mayer@iiasa.ac.at</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
Dear all<br>
<br>
I am running DHCP Server 4.1-ESV-R4 on a Solaris 11 machine. In the same network also a Windows 7 client is connected, all within GNS3.<br>
<br>
This is my simple configuration: ( maybe too simple ) /etc/inet/dhcpd6.conf<br>
<br>
# dhcpd.conf<br>
# Sample configuration file for ISC dhcpd<br>
default-lease-time 600;<br>
max-lease-time 7200;<br>
allow leasequery;<br>
log-facility local7;<br>
shared-network LAN {<br>
subnet6 2001:628:21f0:1::/64 {<br>
range6 2001:628:21f0:1::100 2001:628:21f0:1::1ff ;<br>
option dhcp6.name-servers 2001:628:21f0:1::1 ;<br>
option dhcp6.domain-search "<a href="http://iiasa.ac.at" target="_blank">iiasa.ac.at</a>" ;<br>
}<br>
}<br>
<br>
<br>
Within Solaris I have the following fixed IP configured:<br>
e1000g1:3: flags=20002000941<UP,RUNNING,PROMISC,MULTICAST,IPv6> mtu 1500 index 9<br>
inet6 2001:628:21f0:1::1/64<br>
<br>
I start the dhcpd with the following command in the foreground:<br>
/usr/lib/inet/dhcpd -6 -d -cf /etc/inet/dhcpd6.conf -lf /var/db/isc-dhcp/dhcpd6.leases<br>
<br>
After a while I see on Solaris 11 the following interface:<br>
e1000g1:2: flags=20002004941<UP,RUNNING,PROMISC,MULTICAST,DHCP,IPv6> mtu 1500 index 9<br>
inet6 2001:628:21f0:1::160/128<br>
<br>
To check on Windwos I do: netsh interface ipv6 show route<br>
And I see:<br>
No Manual 256 2001:628:21f0:1::1ba/128 15 Local Area Connection 2<br>
<br>
In both cases a /128 subnet mask.<br>
Why /128 ?<br>
<br>
I can ping the link-local address of the other site in each case but I cannot ping the official 2001:... address. I can ping the own IPv6 address but not the other as it is /128 and therefore not accessible within the network. I would expect that the dhcp daemon gives a /64 address as defined in the 'subnet6' declaration.<br>
<br>
Some ideas what I did wrong ?<br>
<br>
Kind regards<br>
<span class="HOEnZb"><font color="#888888">Hans<br>
<br>
<br>
--<br>
<br>
<br>
<br>
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</font></span></blockquote></div><br><br clear="all"><div><br></div>-- <br>Regards,<div>Mukund</div><br>
</div>