网络地址转换(Network Address Translation) 通过将内部网络的私有IP地址翻译成全球唯一的公网IP地址，使内部网络可以连接到互联网等外部网络上 IPV4 32位 42亿 ， IPV6 128位 A 1~127 B 128~191 C 192~223 D 224~239 E 240~254
私有地址范围 A 10.0.0.0 ~ 10.255.255.255 B 172.16.0.0 ~ 172.31.255.255 C 192.168.0.0 ~ 192.168.255.255NAT实现方式 静态转换 一对一 通常用于服务器发布服务到外网 Easy IP 多对一 通常用于仅仅需要访问公网的时候使用，如办公室环境静态转换是将内部网络的私有地址转换为公有地址时，IP地址的对应关系是确定的 静态转换是一对一的转换 通常用于服务器发布服务到外网 静态转换是双向的
静态转换：可发送服务到外网（服务器一对一）
PC1连接外网 进入外网接口g0/0/1 → nat static global 100.0.0.2 inside 192.168.2.1 （使用Nat的静态转换，将内部的192.168.2.1在与外网互联时转换成公网地址 100.0.0.2） → 测试192.168.2.1 ping 外网 100.0.0.10 （192.168.2.1 一出门，将会转换为外网IP 100.0.0.2）PC2连接外网 进入外网接口g0/0/1 → nat static global 100.0.0.3 inside 192.168.2.2 （使用Nat的静态转换，将内部的192.168.2.2在与外网互联时转换成公网地址 100.0.0.3） → 测试192.168.2.2 ping 外网 100.0.0.10 （192.168.2.2 一出门，将会转换为外网IP 100.0.0.3） 注意：需要配置三个运营商公网IP地址允许将多个内部网址映射到网关出接口 删除静态转换的IP配置 system-view → in g0/0/1 → display this → undo 复制粘贴对应配置 （undo nat static global 100.0.0.3 inside 192.168.2.2 netmask 255.255.255.255）… 确定可以访问公网的设备 system-view → acl 2000 → rule permit source any （或rule permit source 192.168.2.0 0.0.0.255） 配置easy ip in g0/0/1 → nat outbound 2000
[Huawei-GigabitEthernet0/0/1]display this [V200R003C00] # interface GigabitEthernet0/0/1 ip address 100.0.0.1 255.0.0.0 # return [Huawei-GigabitEthernet0/0/1]quit [Huawei]acl 2000 //acl [Huawei-acl-basic-2000]rule permit source any [Huawei-acl-basic-2000]in g0/0/1 [Huawei-GigabitEthernet0/0/1]nat outbound 2000 //nat outbound 2000 [Huawei-GigabitEthernet0/0/1]display this [V200R003C00] # interface GigabitEthernet0/0/1 ip address 100.0.0.1 255.0.0.0 nat outbound 2000 # return [Huawei-GigabitEthernet0/0/1]只需要配置一个运营商公网IP地址
能够在不改变组网的情况下，将多台路由器虚拟成一个虚拟路由器，通过配置虚拟路由器的IP地址为默认网关，实现网关的备份。
VRRP原理配基础IP地址，PC1/PC2/三层交换机接口ip配置 三层交换机及路由器，配置动态路由
[sw1]ospf //设置三层路由sw1的动态路由 [sw1-ospf-1]area 0 [sw1-ospf-1-area-0.0.0.0]network 192.168.1.0 0.0.0.255 [sw1-ospf-1-area-0.0.0.0]network 192.168.2.0 0.0.0.255 //设置sw2的动态路由 [sw2]ospf [sw2-ospf-1]area 0 [sw2-ospf-1-area-0.0.0.0]network 192.168.1.0 0.0.0.255 [sw2-ospf-1-area-0.0.0.0]network 192.168.3.0 0.0.0.255 //设置AR1的动态路由 [AR1]ospf [AR1-ospf-1]area 0 [AR1-ospf-1-area-0.0.0.0]network [AR1-ospf-1-area-0.0.0.0]network 192.168.2.0 0.0.0.255 [AR1-ospf-1-area-0.0.0.0]network 192.168.4.0 0.0.0.255 [AR1-ospf-1-area-0.0.0.0]network 192.168.3.0 0.0.0.255 VRRP配置 [sw1]in vlan 1 [sw1-Vlanif1]vrrp vrid ? INTEGER<1-255> Virtual router identifier [sw1-Vlanif1]vrrp vrid 1 virtual-ip 192.168.1.254 / [sw2]in vlan 1 [sw2-Vlanif1]vrrp vrid 1 virtual-ip 192.168.1.254 /// [sw1-Vlanif1]display vrrp brief //显示为主vrrp VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Master Vlanif1 Normal 192.168.1.254 ---------------------------------------------------------------- Total:1 Master:1 Backup:0 Non-active:0 [sw2-Vlanif1]display vrrp brief //为备份vrrp VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Backup Vlanif1 Normal 192.168.1.254 ---------------------------------------------------------------- Total:1 Master:0 Backup:1 Non-active:0测试 pc1 ping pc2 设置网关为虚拟ip 192.168.1.254 将sw1关机后，sw2 变为master， 后几秒中后可以ping通
<sw2>display vrrp brief VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Master Vlanif1 Normal 192.168.1.254 ---------------------------------------------------------------- Total:1 Master:1 Backup:0 Non-active:0优先级设置 指定备份设备（三层交换机）上设置 vrrp vrid 1 priority 105 （优先级默认值为100）
[sw1]in vlanif 1 [sw1-Vlanif1]display vrrp brief VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Backup Vlanif1 Normal 192.168.1.254 ---------------------------------------------------------------- Total:1 Master:0 Backup:1 Non-active:0 [sw1-Vlanif1]vrrp vrid 1 priority 105 [sw1-Vlanif1]display vrrp brief VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Master Vlanif1 Normal 192.168.1.254 ---------------------------------------------------------------- Total:1 Master:1 Backup:0 Non-active:0案例 3 利用上图 ，删除路由器及pc2，实现vlan2的主机也实现vrrp 在s3700交换机创建vlan2，并且将e0/0/4口加入vlan2
[Huawei]vlan 2 [Huawei-vlan2]in e0/0/4 [Huawei-Ethernet0/0/4]port link-type access [Huawei-Ethernet0/0/4]port default vlan 2再将其他两个接口设置为trunk
[Huawei]port-group [Huawei]port-group 1 [Huawei-port-group-1]group-member Ethernet 0/0/1 Ethernet 0/0/2 [Huawei-port-group-1]port link-type trunk [Huawei-Ethernet0/0/1]port link-type trunk [Huawei-Ethernet0/0/2]port link-type trunk [Huawei-port-group-1]port trunk allow-pass vlan all [Huawei-Ethernet0/0/1]port trunk allow-pass vlan all [Huawei-Ethernet0/0/2]port trunk allow-pass vlan all在三层交换机创建vlan2，并配置vlan2的ip，并将连接s3700的接口设置为trunk
[sw1-vlan2]in vlanif 2 [sw1-Vlanif2]ip address 192.168.2.252 24 [sw1-Vlanif2]in g0/0/1 [sw1-GigabitEthernet0/0/1]port link-type trunk [sw1-GigabitEthernet0/0/1]port trunk allow-pass vlan all //sw2 [sw2]vlan 2 [sw2-vlan2]in vlanif 2 [sw2-Vlanif2]ip address 192.168.2.253 24 [sw2-Vlanif2]in g0/0/1 [sw2-GigabitEthernet0/0/1]port link-type trunk [sw2-GigabitEthernet0/0/1]port trunk allow-pass vlan allVRRP设置，并设置sw2 为master //进入sw1的vlanif2
[sw1]in vlanif 2 [sw1-Vlanif2]vrrp vrid 2 virtual-ip 192.168.2.254 [sw1-Vlanif2]display vrrp brief VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Master Vlanif1 Normal 192.168.1.254 2 Backup Vlanif2 Normal 192.168.2.254 ---------------------------------------------------------------- Total:2 Master:1 Backup:1 Non-active:0 / //sw2的vlanif2设置vrrp [sw2]in vlanif 2 [sw2-Vlanif2]vrrp vrid 2 virtual-ip 192.168.2.254 [sw2-Vlanif2]display vrrp brief VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Backup Vlanif1 Normal 192.168.1.254 2 Backup Vlanif2 Normal 192.168.2.254 ---------------------------------------------------------------- Total:2 Master:0 Backup:2 Non-active:0 [sw2-Vlanif2]vrrp vrid 2 priority 105 //设置sw2的vlanif2 为主 [sw2-Vlanif2]display vrrp brief [sw2-Vlanif2]display vrrp brief VRID State Interface Type Virtual IP ---------------------------------------------------------------- 1 Backup Vlanif1 Normal 192.168.1.254 2 Master Vlanif2 Normal 192.168.2.254 ---------------------------------------------------------------- Total:2 Master:1 Backup:1 Non-active:0