哪两种方法被推荐用来保守网络设备的配置文件不受外网的威胁？（）

A.It creates a global address pool for all outside NAT transactions
B.It establishes a dynamic address pool for an inside static address
C.It creates dynamic source translations for all inside local PAT transactions
D.It creates a one-to-one mapping between an inside local address and an inside global address
E.It maps one inside source address to a range of outside global addresses

A.traceroute address
B.tracert address
C.ssh address
D.telnet address

A.IP
B.ICMP
C.TCP
D.UDP