This applies to both stateful and stateless DHCPv6.

DHCPv6 has a stateless option, where the Server is just used for DHCP options like DNS or Access Point Controller info, without assigning an IP address.

In Junos, this is accomplished with the "other-stateful-configuration" statement:

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/other-stateful-configuration-edit-protocols-router-advertisement.html

• While other vendors' APs work, Cisco's AP does not.

And/or

• In traceoptions, Solicit and Advertise show normal ("Could not find client table entry in routing instance" is expected when using stateless DHCPv6) the following log is seen after the Information Request: "dhcpv6_packet_handle: dhcpv6_validate_msgs failed: Invalid packet"

And

• If a PCAP is done, we can see that the Information-Request packet from the AP contains a "Server-Identifier" option.

This is solved by upgrading to Junos releases:

21.4R3-S6-J1

21.4R3-S7

23.2R2

23.4R2

24.1R1

24.2R1

For more information see PR: https://prsearch.juniper.net/problemreport/PR1779273