AAA is a management mechanism of network security, what security functions it can provide

The customer's two routers are connected together through a LAN, and the two routers form a VRRP backup group and the related configuration is as follows:
[RTA-GigabitEthernet1 /0]display this
ip address 192.168.0.252 255.255.255.0
vrrp vrid 1 virtual-ip 192.168.0.254
vrrp vrid 1 priority 120
[RTB-GigabitEthernet1/0]display this
ip address 192.168.0.253 255.255.255.0
vrrp vrid 1 virtual-ip 192.168.0.254
RTA router GigabitEthernet1/0 interface MAC is 000f-4300-0001, RTB router GigabitEthernet1/0 interface MAC is 000f-4300-0002 If RTA adopts aggregation group Real-mac mode, RTB adopts aggregation group virtual-mac mode, from the above information Learned