单项选择题
A. A VRRP group has one active and one or more standby virtual routers.
B. A VRRP group has one master and one or more backup virtual routers.
C. A VRRP group has one master and one redundant virtual router.
D. None of the other alternatives apply
单项选择题 HSRP has been configured between two Company devices. What kind of message does an HSRP configured router send out every 3 seconds？（）
多项选择题 To protect against first-hop router failure， four protocols were developed to ensure IP routing redundancy. Which of the following are they？（）
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？（）