1、如果交换机上没有做VLAN 可以直接使用：show arp

MPG3560#sh arp

Protocol  Address          Age (min)  Hardware Addr   Type   Interface

Internet  10.16.254.21          228   1cdf.0fdd.1c04  ARPA   GigabitEthernet0/9

Internet  10.16.254.22            -   fcfb.fbc8.7ec9  ARPA   GigabitEthernet0/9

Internet  10.96.166.1             -   fcfb.fbc8.7ec5  ARPA   GigabitEthernet0/5

Internet  10.96.166.2             0   0007.baac.52fb  ARPA   GigabitEthernet0/5

2、如果交换机上做了VLAN，接口是处于VLAN下，show arp 中显示的接口都是vlan的名字。这时需要通过 show arp 先查出mac地址(如查出一个MAC为 b897.5a96.931c )，然后使用 show mac-address-table | in b897.5a96.931c  就可以看到其所在的接口

hotline_3560#sh arp

Protocol  Address          Age (min)  Hardware Addr   Type   Interface

Internet  192.168.96.112          5   c89c.dca3.e77c  ARPA   Vlan1

Internet  192.168.96.113          0   b897.5a96.931c  ARPA   Vlan1  <--查这个IP在哪个接口

Internet  192.168.96.117         33   0021.9b09.7849  ARPA   Vlan1

hotline_3560#sh mac-address-table | in b897.5a96.931c

1    b897.5a96.931c    DYNAMIC     Fa0/13