Non availability of next-header knob for ipv6 on Junos-Evo versions 21.4R2-S1-EVO, 21.4R2-S2-EVO, 21.4R3-S1-EVO and later

If the router has next-header for ipv6 firewall and upgrade is performed above 21.4R3, upgrade will fail.

next-header knob is replaced by the knob payload-protocol.

If upgrade fails, please navigate to config mode and verify the presence of next-header knob, if presents please replace it with payload-protocol.

Please refer TSB:

21.4R2-S1-EVO - Change in IPv6 filter "next-header" match behavior | Salesforce

At the same time, the downgrade will fail if its downgraded from 21.4R3-S1 and above to the versions 21.4R3 and below with payload-protocol knob enabled.

Before downgrade please replace the knob with next-header for the smoother downgrades.