[j-nsp] Bricking EX4500 with 11.4R3 to R4 upgrade

[James Marinas]

Hi Tarko,

Thanks for allowing us to look into the affected units to help us determine that the root cause is an interoperability with 11.4R4 Junos and the U-boot.  This issue is specific to 11.4R4 and the EX4500.  No other platforms are affected.  This is a software problem and recovery could be accomplished via break sequence upon boot and upgrading the jloader.

We have released a PSN detailing the identification and recovery of this issue:

http://www.juniper.net/alerts/viewalert.jsp?actionBtn=Search&txtAlertNumber=PSN-2012-07-663&viewMode=view

In addition, we have appended an alert on the EX4500 11.4R4 download page advising a Jloader upgrade prior to installing 11.4R4.

We apologize for the inconvenience this may have caused you and thanks again for letting us dig in for the root cause.

Regards,

--James