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？（）

多项选择题 You need to decide on the best router redundancy protocol to use in the Company network.  Which  two statements are true about HSRP， VRRP， and GLBP？（）