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Question about Virtual Chassis failover

‎06-08-2009 09:16 AM

I've setup a vritual chassis which includes four members. (Two linecard role, 1 master re, and 1 backup re). I did failover testing for this virtual chassis and found some problems. Below is my testing procedure. (Virtual Chassis is in non-preprovisioning mode)

 

1. Member 1 has a 255 mastership-priority. (Master RE)

    Member  2 has a 254 mastership-priority. (Backup RE)

    Member 0 has an 128 mastership-priority. (Linecard)

    Member 3 has an 128 mastership-priority. (Linecard)

 

2. I shutdown three members as the following sequence.

    Member 1, Member 0, Member3

 

3. I expected Member 2 will be the master re after shutdown member3. But the result was not what I expected. I found that member 2 became linecard instead of Master RE. 

 

What's wrong with it?

 

In addition, I found that when master re was shutdown, all port other switch member will become inactive until new Master RE was elected. Can I shorten the inactive period? 

 

5 REPLIES 5
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Re: Question about Virtual Chassis failover

‎06-08-2009 11:21 AM

It could be how you have you VCP ports configured, do you have a complete loop where every switch is connected to another.  If not you might have a break in which case there might not be a path back to your Backup RE.  Also, to help with failover convergence, try enabling Graceful Routing Engine Switchover.

 

 

set chassis redundancy graceful-switchover


Frank

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Ethernet Switching

Re: Question about Virtual Chassis failover

‎06-08-2009 09:17 PM

Here is the output for "show virtual-chassis". Is it a corret connection for the stacking?

 

 

 

 

 

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Re: Question about Virtual Chassis failover

‎06-08-2009 10:39 PM

Your stack shows a loop which is good.  Since your switch 2 is backup, it should become master after switch 1 goes down, then since 0 and 3 have same priority then 3 might becomme backup due to lowest MAC.  How quickly are you shutting down these switches, are you waiting 5 seconds, 1 minute or 5-10 minutes to give time for switch to go down or are you just removing poower from device to testing.

 

Frank

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Re: Question about Virtual Chassis failover

‎06-08-2009 11:04 PM

I shutdown the switches (remove the power) one by one each five minutes.

My shutdown sequence is : member0 -> member 1 -> member 3

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Re: Question about Virtual Chassis failover

‎06-09-2009 01:22 AM

Hi,

 

That's strange but your problem seems same as this one:

http://forums.juniper.net/jnet/board/message?board.id=switch&message.id=578&query.id=1337508#M578

 

The solution was to use the "set virtual-chassis no-split-detection" statement but this should normaly be used when there are only two devices, but since you are shutting down all the 3 other devices in your stack of 4, I believe that this statement could solve your problem !

 

Let us know what's hapenning

 

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