下面是实验拓扑图:
相关说明:NAT用于提供几乎无限的地址空间并掩藏内部网络寻址方案,地址管理更加容易,它允许严格控制进入和离开网络的流量;但是静态或动态NAT都存在一个问题,它只能提供一对一的地址转换。使用端口地址转换PAT可以实现地址复用的功能,使用PAT后,所有通过地址转换设备的机器都拥有了分配给它们相同IP地址,因此源端口号用来区分不同的连接。实验过程:
I:配置各路由器的IP地址,确保直连接口能Ping通。
II:KC-R1模拟企业网关路由器。
KC-R1(config)#ip route 0.0.0.0 0.0.0.0 173.16.1.128 #指向外网的静态路由 IV:配置NAT。
方法一:静态NAT
KC-R1(config-if)#ip nat inside #将f0/0设置为内网口 *Mar 1 00:05:49.875: %LINEPROTO-5-UPDOWN: Line protocol on Interface NVI0, changed state to up KC-R1(config-if)#ip nat outside #将s1/0设置为外网口 KC-R1(config)#ip nat inside source static 10.1.1.1 173.16.1.56 #静态NAT PC-1#ping 202.101.1.149 #测试证明能通 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 202.101.1.149, timeout is 2 seconds: Success rate is 100 percent (5/5), round-trip min/avg/max = 120/122/132 ms KC-R2#debug ip packet #查看数据包 *Mar 1 00:09:59.487: IP: tableid=0, s=10.1.1.2 (Serial1/0), d=173.16.1.128 (Serial1/0), routed via RIB *Mar 1 00:09:59.491: IP: s=10.1.1.2 (Serial1/0), d=173.16.1.128 (Serial1/0), len 100, rcvd 3 *Mar 1 00:09:59.495: IP: s=173.16.1.128 (local), d=10.1.1.2, len 100, unroutable *Mar 1 00:23:51.243: IP: s=202.101.1.149 (local), d=173.16.1.56 (Serial1/0), len 100, sending *Mar 1 00:23:51.447: IP: tableid=0, s=173.16.1.56 (Serial1/0), d=202.101.1.149 (Loopback0), routed via RIB 方法二:动态NAT
KC-R1(config)# ip nat pool kachy 173.16.1.58 173.16.1.126 netmask 255.255.255.0 #创建地址池 KC-R1(config)#access-list 1 permit 10.1.1.0 0.0.0.255 #创建ACL KC-R1(config)#ip nat inside source list 1 pool kachy #二者关联 PC-1#ping 202.101.1.149 #测试证明能通 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 202.101.1.149, timeout is 2 seconds: Success rate is 100 percent (5/5), round-trip min/avg/max = 96/125/148 ms PC-1#telnet 202.101.1.149 #测试证明能远程连接 Trying 202.101.1.149 … Open Password required, but none set [Connection to 202.101.1.149 closed by foreign host] KC-R1#sh ip nat translations #查看NAT表 Pro Inside global Inside local Outside local Outside global — 173.16.1.58 10.1.1.1 — — — 173.16.1.59 10.1.1.2 — — 方法三:配置PAT
KC-R1(config)#access-list 100 permit ip 10.1.1.0 0.0.0.255 any #创建访问列表 KC-R1(config)#ip nat inside source list 100 interface s1/0 overload #二者关联,地址重载 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 202.101.1.149, timeout is 2 seconds: Success rate is 100 percent (5/5), round-trip min/avg/max = 84/97/116 ms PC-1#telnet 202.101.1.149 Trying 202.101.1.149 … Open Password required, but none set [Connection to 202.101.1.149 closed by foreign host] KC-R1#debug ip nat #查看翻译过程 *Mar 1 00:19:32.843: NAT*: s=10.1.1.1->173.16.1.56, d=202.101.1.149 [46610] *Mar 1 00:19:32.847: NAT*: s=10.1.1.1->173.16.1.56, d=202.101.1.149 [46611] *Mar 1 00:19:33.083: NAT*: s=202.101.1.149, d=173.16.1.56->10.1.1.1 [31823] *Mar 1 00:23:34.931: IP: tableid=0, s=173.16.1.56 (Serial1/0), d=202.101.1.149 (Loopback0), routed via RIB *Mar 1 00:23:34.935: IP: s=173.16.1.56 (Serial1/0), d=202.101.1.149, len 100, rcvd 4 *Mar 1 00:23:34.939: IP: tableid=0, s=202.101.1.149 (local), d=173.16.1.56 (Serial1/0), routed via FIB OK,实验完成。 |