通过IP地址获取MAC地址及其对应的交换机端口

而在思科交换机搭建的环境中，是能做到通过对方MAC/IP地址来查找对端对应的交换机端口的，具体步骤如下：

　　假设对端的MAC地址为：192.168.1.101

　　在中心交换机（核心层交换机或汇聚层交换机）上输入:

switch-6509#show ip arp | in 192.168.1.101
Internet 192.168.50.47 2 0011.2233.4455 ARPA Vlan50

　　在ARP表中我们找到了和192.168.1.101对应的MAC地址，如果要根据MAC地址查找对应交换机端口，可从下面开始操作。

switch-6509#show mac address-table | in 0011.2233.4455

Mac Address Table
——————————————-

Vlan Mac Address Type Ports
—- ———– ——– —–
120 0011.2233.4455 DYNAMIC Gi1/0/3
Total Mac Addresses for this criterion: 1

　　可以在MAC地址表中发现MAC地址0011.2233.4455是从端口G1/0/3学习过来的，继续向下层排查。

switch-6509#show cdp nei g1/0/3 detail

Device ID: IDC-2960G48-A14-114
Entry address(es):
IP address: 192.168.1.102
Platform: cisco WS-C2960G-48TC-L, Capabilities: Switch IGMP
Interface: GigabitEthernet1/0/3, Port ID (outgoing port): GigabitEthernet0/48
Holdtime : 120 sec

Version :
Cisco IOS Software, C2960 Software (C2960-LANBASEK9-M), Version 12.2(50)SE5, REL
EASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Tue 28-Sep-10 13:44 by prod_rel_team

advertisement version: 2
Protocol Hello: OUI=0x00000C, Protocol ID=0×0112; payload len=27, value=0000000
0FFFFFFFF010221FF000000000000B8BEBF549D00FF0000
VTP Management Domain: ”
Native VLAN: 1
Duplex: full
Management address(es):
IP address: 192.168.1.102

　　我们发现下层连接的是2960的接入层交换机，登陆到此交换机。

switch-2960#show mac address-table | in 0011.2233.4455

Mac Address Table
——————————————-

Vlan Mac Address Type Ports
—- ———– ——– —–
120 0011.2233.4455 DYNAMIC Fa1/0/30
Total Mac Addresses for this criterion: 1

　　即可发现该MAC/IP地址所对应的端口是2960交换机的f1/0/30口，若继续通过跳线追查可以发现该用户的具体位置。