多项选择题 HSRP is being set up between two Company devices.  In what three states is it possible for an  HSRP router to be in？（）

多项选择题 R1 and R2 exchange HSRP between each other in the Company network.  In which three HSRP  states do routers send hello messages？（）

单项选择题 You need to implement a high availability design in the Company routed network.  Which protocol  allows for the automatic selection and simultaneous use of multiple available gateways as well as  automatic failover between those gateways？（）