This article explains whether the QFX5K series switches support Dual-DR mode for the PIM protocol.

Noticing below warning under "set protocols pim interface <interface-name> dual-dr" in latest versions but not seen in old version like 13.X.

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## Warning: statement ignored: unsupported platform (qfx5100-48s-6q)

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dual-dr;

The statement introduced in Junos OS Release 13.2X51 for the QFX Series however PIM Dual-DR mode is only supported on QFX10K series switches and is not supported or functional on QFX5K platforms. 

In Junos OS 13.x[old version], the system accepted the dual-dr configuration without warnings, even though the feature was non-functional/not supported on QFX5100 switches but in latest versions, it is prompting the warning correctly. Since the PIM Dual-DR mode is not supported on QFX5K devices, you can safely remove this configuration from device.

Reference links: Protocol Independent Multicast (PIM) Dual Designated Router Mode | Juniper Networks Pathfinder Feature Explorer

https://apps.juniper.net/feature-explorer/feature/3650?fn=Protocol%20Independent%20Multicast%20(PIM)%20Dual%20Designated%20Router%20Mode&

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/protocols-pim-interface-dual-dr.html