[j-nsp] Junos upgrade how to

[james list]

Hi gents,
I'm looking for the following info:

1) EX8200 (no VC) with dual RE (11.4): is it supported ISSU ?

2) in case question 1) answer is no and I need to use NSSU, do I've to
download the new junos image on both RE0 and RE1 before to launch NSSU ?

3) EX4200 in VC (11.4): is it supported ISSU ?

4) in case question 3) answer is no and I need to use NSSU, do I've to
download the new junos image on all the line cards before to launch NSSU ?

5) SRX5k and 3k cluster with dual RE (12.1X44), if I want to run ISSU do
I've to download new Junos image on all the RE ?

Any feedback/suggestion and reference url is appreciated.

Greetings
james