The upgrade path is directed by the release notes of your ultimate version. The first number is the major version indicating the year of release. The second Junos number is the minor version. 20.4 is the EEOL release.
The documentation landing page for the platform provides a jumping off for all the related information.
https://www.juniper.net/documentation/product/us/en/ex3300Select release notes > then the version
Junos 20.4 allows for a 3 major version jump on EEOL (extended end of life) releases. These are the notes specifically for EX platforms.
https://www.juniper.net/documentation/en_US/junos/information-products/topic-collections/release-notes/20.4/topic-150424.html#jd0e4130Then checking Junos 18 (since junos 17 does not exist and it is also a half way point). We see the same support of 3 versions is allowed coming from 15.
https://www.juniper.net/documentation/en_US/junos/information-products/topic-collections/release-notes/18.4/topic-142592.html#jd0e4994So you jump from 15x > 18.4 > 20.4
Two steps.
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Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
http://puluka.com/home------------------------------
Original Message:
Sent: 09-07-2021 18:16
From: Unknown User
Subject: Upgrading EX3400 15.1X53-D58.3 to 20.4R2.7
Hello community.
I wanted to know if I can upgrade an EX3400-48P straight from 15.1X53-D58.3 to 20.4R2.7, or what steps are recommended.
Thank you.