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<TITLE>RE: [j-nsp] M20 redundancy config?</TITLE>
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<P><FONT SIZE=2>Only one addition from me;</FONT>
</P>
<P><FONT SIZE=2>Use the feature 'keepalive-time' under [chassis redundancy].</FONT>
<BR><FONT SIZE=2>Its turned off automatically by default, and when enabled it will allow the backup RE to assume master control within x seconds if it detects loss of keepalives from the master.</FONT></P>
<P><FONT SIZE=2>Default is 300 secs (5 mins), and the minimum is 2 secs.</FONT>
<BR><FONT SIZE=2>******************************************************</FONT>
<BR><FONT SIZE=2>Be aware though that pre-JUNOS 5.4 the minimum time is 300 seconds.</FONT>
<BR><FONT SIZE=2>JUNOS 5.4 and after the minimum is 2 seconds.</FONT>
<BR><FONT SIZE=2>******************************************************</FONT>
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<P><FONT SIZE=2>From the manual;</FONT>
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<P><FONT SIZE=2>The range for keepalive-time is 2 through 10,000 seconds.</FONT>
</P>
<P><FONT SIZE=2>If you configure the keepalive time for 2 seconds, the sequence of events is as follows:</FONT>
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<P><FONT SIZE=2>After 2 seconds of keepalive loss, a message is logged. </FONT>
<BR><FONT SIZE=2>After 2 seconds of keepalive loss, the backup Routing Engine attempts to assume mastership. An alarm is generated whenever the backup is active and the display is updated with current status. </FONT></P>
<P><FONT SIZE=2>Once the backup Routing Engine assumes mastership, it continues to function as master even after the originally configured master Routing Engine has successfully resumed operation. You must intervene to restore its previous backup status. However, if at any time one of the Routing Engines is not present, the other one becomes master automatically, regardless of how redundancy is configured. </FONT></P>
<P><FONT SIZE=2>OR</FONT>
</P>
<P><FONT SIZE=2>The range for keepalive-time is 300 through 10,000 seconds.</FONT>
</P>
<P><FONT SIZE=2>The sequence of events is as follows:</FONT>
</P>
<P><FONT SIZE=2>After 20 seconds of keepalive loss, a message is logged. </FONT>
<BR><FONT SIZE=2>After 300 seconds of keepalive loss (the default setting), the backup Routing Engine attempts to assume mastership. An alarm is generated whenever the backup is active and the display is updated with current status. </FONT></P>
<P><FONT SIZE=2>Once the backup Routing Engine assumes mastership, it will continue to function as master even after the originally configured master Routing Engine has successfully resumed operation. Operator intervention is required to restore its previous backup status. However, if at any time one of the Routing Engines is not present, the other one becomes master automatically, regardless of how redundancy is configured. </FONT></P>
<BR>
<P><FONT SIZE=2>HTH, Neil.</FONT>
</P>
<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: billp [<A HREF="mailto:billp@wjp.net">mailto:billp@wjp.net</A>]</FONT>
<BR><FONT SIZE=2>Sent: 23 May 2003 14:13</FONT>
<BR><FONT SIZE=2>To: juniper-nsp@puck.nether.net</FONT>
<BR><FONT SIZE=2>Subject: [j-nsp] M20 redundancy config?</FONT>
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<BR>
<P><FONT SIZE=2>After looking through all the docs and notes, I have come up with</FONT>
<BR><FONT SIZE=2>the following config to enable reduncancy on an M20 (installed</FONT>
<BR><FONT SIZE=2>dual RE and dual SSB):</FONT>
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<P><FONT SIZE=2>chassis {</FONT>
<BR><FONT SIZE=2> redundancy {</FONT>
<BR><FONT SIZE=2> routing-engine 0 master;</FONT>
<BR><FONT SIZE=2> routing-engine 1 backup;</FONT>
<BR><FONT SIZE=2> ssb 0 preferred;</FONT>
<BR><FONT SIZE=2> failover on-loss-of-keepalives;</FONT>
<BR><FONT SIZE=2> }</FONT>
<BR><FONT SIZE=2>}</FONT>
</P>
<P><FONT SIZE=2>I also use "commit sync" when committing configs, and try and</FONT>
<BR><FONT SIZE=2>do a "request system snapshot" on both RE's individually, </FONT>
<BR><FONT SIZE=2>occasionally.</FONT>
</P>
<P><FONT SIZE=2>Question is- is this the proper configuration and operational</FONT>
<BR><FONT SIZE=2>way to ensure redundancy in case of an RE or SSB failure?</FONT>
</P>
<P><FONT SIZE=2>Is there a better 'best practice'?</FONT>
</P>
<P><FONT SIZE=2>Any input appreciated. Any other ideas/methods to increase</FONT>
<BR><FONT SIZE=2>reliability/failover/etc would also be appreciated.</FONT>
</P>
<P><FONT SIZE=2>thanks</FONT>
<BR><FONT SIZE=2>bill</FONT>
</P>
<P><FONT SIZE=2>_______________________________________________</FONT>
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