Hello @Charlie Grey ,
ip pim hello-iinterval specifies when PIM hellos are sent to keep up a PIM adjacency. Default value should be 30 seconds.
ip pim query-interval
I have found the following good explanation, they are actually the same but query refers to PIM version 1.
>> Use this command to configure the frequency of PIM neighbor discovery messages. By default these messages are sent once every 30 seconds. In PIM Version 1 (PIMv1), these messages are referred to as PIM query messages; in PIM Version 2 (PIMv2), these messages are referred to as PIM hello messages. By default, routers run PIMv2 and send PIM hello messages. A router will change (auto-fallback) to PIMv1 and will send PIM query messages if it detects a neighboring router that only supports PIMv1. As soon as that neighboring PIMv1 router is removed from the network, the router will revert to PIMv2.
Hope to help
Giuseppe
