Switching

Hi all. Currently I'm in the process of upgrading EX3300/4300/4600 switches(some in virtual chassis) to new Junos OS listed in the download section.

Most of the switches haven't been upgraded in a few years so they have out of date Junos OS on them. I was wondering if I can upgrade immediately to the latest release or do I need to use incremental updates?

For example if I have an EX4300 virtual chassis with Junos OS 14.1X53 can I go straight to Junos OS 20.1/2 or do I need to do incremental upgrades to the release I want?

Thanks in advance for all the help.

Hi Igor,

there are lots of threads within the J-Net forum with the identical question. E.g. here:

https://forums.juniper.net/t5/Ethernet-Switching/EX4300-48p-VC-upgrade/m-p/478550

Also please check the recommended firmware page for each device, as the latest and greatest releases (currently 19.4 - 20.3) could have some stability issues:

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

Hello Igor:

You cannot upgrade skipping more than 3 mayor releases for example from version 14 over to 18 directly. For example you can follow the following upgrade path:

• 14.1X53 to 16.X
• 16.X to 18.X
• 18.x to 20.X

The other alternative, if you want to upgrade directly is with a format install:

https://kb.juniper.net/InfoCenter/index?page=content&id=KB20643&actp=METADATA

https://kb.juniper.net/InfoCenter/index?page=content&id=KB31265 

Take in consideration that 20.X is not a stable version for the moment. I suggest to check the following document: https://kb.juniper.net/InfoCenter/index?page=content&id=KB21476

Regards

Thanks to both of you for the responses. I will use the upgrade path  you suggested to the version 18.X.

I would suggest not skipping version 15. I think that's when FreeBSD was upgraded.

Last attempt - step not needed.  With direct you'll get FreeBSD upgrade as well.

FYI

Additional info here regarding FreeBSD upgrade (and potential need for downgrade).  This still calls out old multi-step stuff 😩. Best is to NOT use validate option or specify no-validate explicitly (I have never needed this):

https://www.juniper.net/documentation/en_US/junos/topics/topic-map/upgrading-and-downgrading-to-upgraded-bsd.html#id-upgrading-junos-os-with-upgraded-freebsd

Also see this KB - https://kb.juniper.net/InfoCenter/index?page=content&id=KB31903&cat=EX4300_1&actp=LIST&showDraft=false

Just to be clear after all this. The upgrade path should be:

1. upgrade to 15.1 -> this step will also upgrade FreeBSD

2. upgrade to  17.1

3. upgrade to 18.X -> I will go for last minor release within this major release

Will this cover all of the potential pitfalls for upgrades?