|
利用Internet 出口线路建立VPN通道实现总、分公司之间的互联，是目前许多公司热衷的方案。以往要建立这样的VPN，需要至少一端使用静态的IP地址。当前很多公司都通过ADSL方式上网，如果要求电信提供静态地址，费用将会大大增加（如深圳512K固定IP的ADSL月租是RMB5000）。现在Cisco IOS 12.3(4)T中新增了根据DNS名称来建立VPN peer 的命令，借助希网(3322.org)、88ip等动态域名解释系统的配合，可以在VPN两端都使用动态地址的ADSL线路,节省大笔费用。 关键命令： set peer {host-name [dynamic] | ip-address} 说明： host-name 指定IPSec peer的DNS主机名称，如：myhost.example.com。 dynamic (可选参数) 指定 IPSec peer 的主机名在需要建立IPSec通道的时候才通过DNS服务器解释为IP地址。 ip-address 直接给出IPSec peer的IP地址（传统的配置方式）。 示例拓扑图：  为简单起见实验中使用的是静态地址，实际环境中局域网内应在一台机器上运行动态域名解释客户端程序，以将主机名nbo.3322.org注册到服务器，注册地址是路由器的外网端口地址。 配置: VPN-1(省略了部分无关配置): version 12.3 ! hostname vpn-1 ! aaa new-model ! aaa authentication login authen group radius local aaa authorization network author local aaa session-id common ip subnet-zero ! ip cef ip name-server 202.96.134.133 ! crypto isakmp policy 10 authentication pre-share group 2 crypto isakmp key cisco address 0.0.0.0 0.0.0.0 ! crypto ipsec transform-set s2s esp-des esp-sha-hmac ! crypto dynamic-map dymap 1 set transform-set s2s match address 110 ! crypto map mymap 1 ipsec-isakmp dynamic dymap ! interface FastEthernet0/0 description VPN ip address 202.11.22.11 255.255.255.248 ip nat outside crypto map mymap ! interface FastEthernet0/1 description INSIDE_GATEWAY ip address 172.16.10.110 255.255.0.0 ip nat inside ! ip nat inside source route-map nonat interface FastEthernet0/0 overload ip classless ip route 0.0.0.0 0.0.0.0 FastEthernet0/0 no ip http server ! access-list 110 permit ip 172.16.0.0 0.0.255.255 172.30.1.0 0.0.0.255 access-list 120 deny ip 172.16.0.0 0.0.255.255 172.30.1.0 0.0.0.255 access-list 120 permit ip 172.16.0.0 0.0.255.255 any route-map nonat permit 10 match ip address 120 ! end VPN-2(省略了部分无关配置): version 12.3 ! hostname vpn-2 ! username mize password 0 http://mize.netbuddy.org no aaa new-model ip subnet-zero ! ip cef ip name-server 202.96.134.133 ! crypto isakmp policy 1 authentication pre-share group 2 crypto isakmp key cisco hostname nbo.3322.org ! crypto ipsec transform-set s2s esp-des esp-sha-hmac ! crypto map mymap 10 ipsec-isakmp set peer nbo.3322.org dynamic set transform-set s2s match address 110 ! interface FastEthernet0/0 ip address 202.11.22.43 255.255.255.248 ip nat outside crypto map mymap ! interface FastEthernet0/1 ip address 172.30.1.1 255.255.255.0 ip nat inside ! ip nat inside source route-map nonat interface FastEthernet0/0 overload ip classless ip route 0.0.0.0 0.0.0.0 FastEthernet0/0 ! access-list 110 permit ip 172.30.1.0 0.0.0.255 172.16.0.0 0.0.255.255 access-list 120 deny ip 172.30.1.0 0.0.0.255 172.16.0.0 0.0.255.255 access-list 120 permit ip 172.30.1.0 0.0.0.255 any route-map nonat permit 10 match ip address 120 ! end 相关调试命令： show cry isa sa show cry ipsec sa (责任编辑：IT) |