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 (email@example.com, 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.
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.