求解一个VPN实例各项配置意思

pounding

求解各行配置意思，主要是VPN和AAA配置，其他可略过，谢谢啦
Router#show run
Building configuration...

Current configuration : 1264 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router
!
!
!
!
!
!
!
aaa new-model
!
aaa authentication login VPNAUTH local
!
!
aaa authorization network VPNAUTH local
!
!
!
!
!
username nssb password 0 nssb
!
crypto isakmp policy 10
encr aes 256
authentication pre-share
group 2
!
!
crypto isakmp client configuration group ciscogroup
key ciscogroup
pool VPNCLIENTS
netmask 255.255.255.0
!
!
crypto ipsec transform-set mytrans esp-3des esp-sha-hmac
!
crypto dynamic-map mymap 10
set transform-set mytrans
reverse-route
!
crypto map mymap client authentication list VPNAUTH
crypto map mymap isakmp authorization list VPNAUTH
crypto map mymap client configuration address respond
crypto map mymap 10 ipsec-isakmp dynamic mymap
!
!
!
ip ssh version 1
!
!
!
!
!
!
interface FastEthernet0/0
ip address 10.3.0.1 255.255.255.0
duplex auto
speed auto
crypto map mymap
!
interface FastEthernet0/1
ip address 10.2.0.1 255.255.255.0
duplex auto
speed auto
!
interface Vlan1
no ip address
shutdown
!
ip local pool VPNCLIENTS 10.1.1.100 10.1.1.200
ip classless
ip route 10.0.0.0 255.255.255.0 10.3.0.2
!
!
!
!
!
!
!
line con 0
login
line vty 0 4
login
!
!
!
end