tag:help-archives.hannonhill.com,2010-02-09:/discussions/installation/720-need-information-on-multicast-protocol-required-by-cascade-7xCascade CMS: Discussion 2014-03-25T20:56:01Ztag:help-archives.hannonhill.com,2010-02-09:Comment/211535122012-11-20T20:45:19Z2012-11-20T20:45:19ZNeed Information On Multicast Protocol Required By Cascade 7.X<div><p>Hi John,</p>
<p>The multicast level in Cascade 7.x is set at
<strong>32</strong>.</p>
<p>A sample configuration can be found at the bottom of the
<strong>ehcache.xml</strong> configuration file that is located in
<em>tomcat/conf</em>. The level is indicated by the
<strong>timeToLive</strong> parameter.</p>
<pre>
<code>...
<cacheManagerPeerProviderFactory
class="net.sf.ehcache.distribution.RMICacheManagerPeerProviderFactory"
properties="peerDiscovery=automatic, multicastGroupAddress=230.0.0.1,
multicastGroupPort=4446, timeToLive=32"/>
...</code>
</pre>
<p>Additional information about the <em>timeToLive</em> parameter
can be <a href=
"http://ehcache.org/documentation/user-guide/rmi-replicated-caching#multicast-not-propagating-far-enough-or-propagating-too-far">
found here</a>.</p>
<p>Please let us know if you have any questions.</p>
<p>Thanks</p></div>Ryan Griffithtag:help-archives.hannonhill.com,2010-02-09:Comment/211535122012-11-20T21:13:21Z2012-11-20T21:30:34ZNeed Information On Multicast Protocol Required By Cascade 7.X<div><p>The multicast level is not the same as the TTL.<br>
I have additional comments to folllow this description of
multicast.</p>
<p><strong>Multicast level refers to the following:</strong></p>
<p>Level 0:</p>
<blockquote>
<p>is the no support for IP Multicasting level. Lots of hosts and
routers in the Internet are in this state, as multicast support is
not mandatory in IPv4 (it is, however, in IPv6). Not too much
explanation is needed here: hosts in this level can neither send
nor receive multicast packets. They must ignore the ones sent by
other multicast capable hosts.</p>
</blockquote>
<p>Level 1:</p>
<blockquote>
<p>is the support for sending but not receiving multicast IP
datagrams level. Thus, note that it is not necessary to join a
multicast group to be able to send datagrams to it. Very few
additions are needed in the IP module to make a Level 0 host Level
1-compliant.</p>
</blockquote>
<p>Level 2:</p>
<blockquote>
<p>is the full support for IP multicasting level. Level 2 hosts
must be able to both send and receive multicast traffic. They must
know the way to join and leave multicast groups and to propagate
this information to multicast routers. Thus, they must include an
Internet Group Management Protocol (IGMP) implementation in their
TCP/IP stack.</p>
</blockquote>
<p><strong>Multicasting and linux</strong></p>
<p>Linux is, full Level-2 Multicast-Compliant. It meets all
requirements to send, receive and act as a router (mrouted) for
multicast datagrams. Once the kernel is configured and installed,
you should provide a default route for multicast traffic. The goal
is to add a route to the network 224.0.0.0:<br>
route add 224.0.0.0 netmask 240.0.0.0 dev eth0</p>
<p>Based on the description of the dependency of 7.x for multicast
to support cache synchronization the network to do support this
functionality MUST be pier to pier which would absolutely require
level 2 multicasting.</p>
<p>This became a question of concern with our network folks as they
regulate things like multicast levels and they wanted to know.</p>
<p>If you any contrary information let me know.</p>
<p>Thanks,<br>
John Hayes</p></div>jhhtag:help-archives.hannonhill.com,2010-02-09:Comment/211535122012-11-20T21:34:20Z2012-11-20T21:34:20ZNeed Information On Multicast Protocol Required By Cascade 7.X<div><p>Hi John,</p>
<p>My apologies for the misunderstanding.</p>
<p>You are correct, <em>Level 2</em> would be required because
traffic is both sent and received.</p>
<p>Please let us know if you have any additional questions.</p>
<p>Thanks</p></div>Ryan Griffith