1. 组网需求
Switch B通过以太网端口Ethernet1/1连接到DHCP服务器，通过以太网端口Ethernet1/2、Ethernet1/3连接到DHCP客户端。要求：l与DHCP服务器相连的端口可以转发DHCP服务器的响应报文，而其他端口不转发DHCP服务器的响应报文。l记录DHCP-REQUEST和信任端口收到的DHCP-ACK广播报文中DHCP客户端IP地址及MAC地址的绑定关系。
配置步骤# 使能DHCP Snooping功能。<SwitchB> system-view[SwitchB] dhcp-snooping# 配置Ethernet1/1端口为信任端口。[SwitchB] interface ethernet 1/1[SwitchB-Ethernet1/1] dhcp-snooping trust[SwitchB-Ethernet1/1] quit支持Option 82配置举例1. 组网需求lSwitch B上使能DHCP Snooping功能，并支持Option 82功能；l对包含Option 82的请求报文的处理策略为replace；l在Ethernet1/2上配置Ciruict ID填充内容为company001，Remote ID填充内容为device001；l在Ethernet1/3上配置以verbose模式填充Option 82，接入节点标识为sysname，填充格式为ASCII格式。lSwitch B将添加Option 82的DHCP请求报文转发给DHCP服务器Switch A，使得DHCP客户端可以获取到IP地址。
3. 配置步骤# 使能DHCP Snooping功能。<SwitchB> system-view[SwitchB] dhcp-snooping# 配置Ethernet1/1端口为信任端口。[SwitchB] interface ethernet 1/1[SwitchB-Ethernet1/1] dhcp-snooping trust[SwitchB-Ethernet1/1] quit# 在Ethernet1/2上配置DHCP Snooping支持Option 82功能。[SwitchB] interface ethernet 1/2[SwitchB-Ethernet1/2] dhcp-snooping information enable[SwitchB-Ethernet1/2] dhcp-snooping information strategy replace[SwitchB-Ethernet1/2] dhcp-snooping information circuit-id string company001[SwitchB-Ethernet1/2] dhcp-snooping information remote-id string device001[SwitchB-Ethernet1/2] quit# 在端口Ethernet1/3上配置DHCP Snooping支持Option 82功能。[SwitchB] interface ethernet 1/3[SwitchB-Ethernet1/3] dhcp-snooping information enable[SwitchB-Ethernet1/3] dhcp-snooping information strategy replace[SwitchB-Ethernet1/3] dhcp-snooping information format verbose node-identifier sysname[SwitchB-Ethernet1/3] dhcp-snooping information circuit-id format-type ascii[SwitchB-Ethernet1/3] dhcp-snooping information remote-id format-type ascii