Hello Brock0150,
>> Is there a relationship between a mulitcast DR and a gateway of last resort?
generally speaking there is no relationship between these two concepts:
a multicast DR is elected per segment based on PIM priority and on interface IP address
A gateway of last resort is a device that is considered a border router to all unknown unicast IP prefixes.
Said this, you can have a network segment where a device acts as PIM DR and it is also considered by other devices the gateway of last resort.
>> Also, is there any special configurtion needed for setting up multicast on HSRP networks?
Some specific issues can arise and you should be fine if HSRP active and PIM DR are the same router.
Hope to help
Giuseppe
