内容摘要：由于楼内经常存在私开的DHCP服务器，导致大量主机无法分配到合法IP地址；另外，由于有相当数量的主机指定IP地址，因此造成了与DHCP分配的IP地址冲突。以上两方面，均造成了该公寓楼大量主机无法正常访问网络。
接下来配置Dynamic ARP Inspection
1 show cdp neighbors 检查交换机之间的连接情况
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
ap Gig 1/0/23 149 T AIR-AP1230Fas 0
hall-3750 Gig 1/0/27 135 S I WS-C3750-2Gig 1/0/1
1#west-3750 Gig 1/0/28 173 S I WS-C3750G-Gig 1/0/25
2 configure terminal 进入全局配置模式
3 ip arp inspection vlan 103 在VLAN 103上启用Dynamic ARP Inspection
4 interface GigabitEthernet1/0/28 进入第28端口
5 ip arp inspection trust 将端口设置为受信任端口
The switch does not check ARP packets that it receives from the other switch on the trusted interface. It simply forwards the packets.
6 end
配置完成后可以用如下命令观察Dynamic ARP Inspection的运行情况
show arp access-list [acl-name] Displays detailed information about ARP ACLs.
show ip arp inspection interfaces [interface-id] Displays the trust state and the rate limit of ARP packets for the specified interface or all interfaces.
Interface Trust State Rate (pps) Burst Interval
--------------- ----------- ---------- --------------
Gi1/0/21 Untrusted 15 1
Gi1/0/22 Trusted None N/A
Gi1/0/23 Untrusted 15 1
Gi1/0/24 Trusted None N/A
Gi1/0/25 Untrusted 15 1
责编：豆豆技术应用