原版CCNA教材19章NATppt课件.ppt

第十九章网络地址翻译 NAT
NAT——网络地址翻译
随着Internet的飞速发展，网上丰富的资源产生着巨大的吸引力
接入Internet成为当今信息业最为迫切的需求
但这受到IP地址的许多限制
首先，许多局域网在未联入Int
Ping ……
Ping !!!!!
ip nat pool dyn-nat  netmask
ip nat inside source list 1 pool dyn-nat
!
interface Ethernet0
ip address
ip nat inside
!
interface Serial0
ip address
ip nat outside
!
access-list 1 permit
!
动态NAT的配置
Translate between inside hosts addressed from to  the globally unique network.
This interface connected to the outside world.
This interface connected to the inside network.
PAT的配置
ip nat pool ovrld-nat
netmask
ip nat inside source list 1 pool ovrld-nat overload
!
interface Ethernet0/0
ip address
ip nat inside
!
interface Serial0/0
ip address
ip nat outside
!
access-list 1 permit
Router#sh ip nat trans
Pro Inside global Inside local Outside local Outside global
tcp :11003 :11003 :23 :23
tcp :1067 :1067 :23 :23
Verifying NAT
A translation for a Telnet is still active. Two different inside hosts appear on the outside with a single IP address.
Basic IP address translation
Unique TCP port numbers are used to distinguishbetween hosts.
Router#show ip nat trans
Pro Inside global Inside local Outside local Outside global
--- --- ---
--- --- ---
IP address translation with overloading
Router#debug ip nat
NAT: s=->, d= [0]
NAT*: s=, d=-> [0]
NAT: s=->, d= [1]
NAT: s=->, d= [2]
NAT: s=->, d= [3]
NAT*: s=, d=-> [1]
NAT: s=->,