Ethernet Switching
Ethernet Switching

Kernel panic when trying to downgrade 4550 switch

‎05-01-2013 12:29 PM

Hi, we currently have two 4200 switches in a switch stack.  We purchased some additional EX4550 switches to expand the switch stack.  We were told by Juniper support that they all have to be on the same Junos OS version for this to work.

 

Our current EX4200 switch stack is on 10.3R1.9

 

Our new EX4550 switches are on 12.2R1.8

 

The newest version of Junos for the 4200 is 11.4R5.7.  So we were told we need upgade the 4200s and downgrade the 4550s so everything was on the same 11.4R5.7 version.  Sounds easy enough....

 

I started with the 4550s since they are not in production.  Attempting to downgrade results in this:

 

FreeBSD/PowerPC U-Boot bootstrap loader, Revision 2.4
(builder@faranth.juniper.net, Sun Oct 21 02:30:59 UTC 2012)
Memory: 2048MB
bootsequencing is enabled
bootsuccess is set
new boot device = disk0s1:
Package /jinstall-ex-4500-11.4R5.7-domestic-signed.tgz is signed...
/kernel data=0x5fbb0c+0x72fa8 syms=[0x4+0x5ce50+0x4+0x8ac34]
Kernel entry at 0x800000e0 ...
GDB: no debug ports present
KDB: debugger backends: ddb
KDB: current backend: ddb
dog: ERROR - reset of uninitialized watchdog
panic: Invalid board type information
dog: ERROR - reset of uninitialized watchdog
KDB: enter: panic
dog: ERROR - reset of uninitialized watchdog
[thread pid 0 tid 0 ]
Stopped at      kdb_enter+0x1a4:        addis   r3, r0, -0x7faa
db>

 

At that point you are hosed and have to pull the power cable and start over.  I attempted installation from disk, from USB, FTP etc. it all fails.  I got Junos support on and they remotely connected to my PC and attempted the same thing for hours and eventually concluded my switch is bad and they will swap it out.  However it does the same thing on all four switches.  Did we really just purchase four brand new bad switches?  That seems very unlikely.

 

Next I figured well let me try and upgrade them.  I got version 12.3 from the website and it went right on with no issues and upgraded.  Doesn't seem likely if they were all bad.

 

I googled around and found others having the same problem when attempting to downgrade so that makes me believe the issue is more widespread and not just bad hardware that I have.  I never did find a resolution that anyone posted though.

 

Does anyone have any ideas?  I could round up all four switches and mail back to Juniper and get four new ones but I'm pretty certain they will be the same and just waste a lot of time and shipping costs.

5 REPLIES 5
Ethernet Switching

Re: Kernel panic when trying to downgrade 4550 switch

‎05-01-2013 10:23 PM

Why not just upgrade your EX4200s to the same version of 12.1 as the 4550s?

Ben Dale
JNCIP-ENT, JNCIP-SP, JNCIP-DC, JNCIE-SEC #63
Juniper Ambassador
Follow me @labelswitcher
Ethernet Switching

Re: Kernel panic when trying to downgrade 4550 switch

‎05-02-2013 05:54 AM

Hello,

EX4550 are supported starting from JUNOS 12.2R1 

http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/concept/ex-series-software-fe...

Mixed VC with EX4200 and EX4550 is supported starting from JUNOS 12.2R1

http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/concept/ex-series-software-fe...

HTH

Thanks

Alex

 

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Ethernet Switching

Re: Kernel panic when trying to downgrade 4550 switch

‎05-02-2013 07:31 AM

According to this page 11.4R5.7 is the newest version available for the EX4200

 

http://kb.juniper.net/InfoCenter/index?page=content&id=KB21476

 

However I just went into the Junos downloads and found 12.x versions available for the 4200 series.  I wonder why Juniper's own tech support didn't know this while we spent hours on the phone hashing this out.  Crazy.

Ethernet Switching

Re: Kernel panic when trying to downgrade 4550 switch

‎05-02-2013 07:32 AM
Ethernet Switching

Re: Kernel panic when trying to downgrade 4550 switch

‎05-03-2013 01:42 AM

Malcom, those are not the latest releases just the recommended code for each device.

You need to go to the download page where you can see the latest releases and release notes.