How to find the port of switch base on ip address

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Mar 6th, 2007
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Hi,All,

Do you someone may give me some guide on how to relocate the port of switch base on I know ip address?Actually this is important when I knew someone computer send out lots of traffic.

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If you know the IP address of the suspected device;


1. Go to the default gateway (router/L3 Switch) and do a Show arp with the known IP address.


2. Arp should come back with the MAC address associated with the known IP address.


3. On the subject switch, do a show mac-address (IOS), or show cam static (CatoS). The output of these commands will show you the MAC address and Port/Interface# where that MAC address is being seen.



Jon Marshall Tue, 03/06/2007 - 07:06
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Hi


You don't say whether the switch is layer 2 or layer 3 and whether it is IOS or CatOS.


Assuming IOS.


On the layer 3 device, whether that is the switch itself or a router,


1) show arp | include "ip address" eg


NW-MSQ1-F02-CS1#sh arp | include 10.180.172.34

Internet 10.180.172.34 64 000e.d797.1a7f ARPA FastEthernet2/1


2) On the switch


sh mac-address-table address 000e.d797.1a7f


This will give you the port that the switch has registered this mac address against.


HTH


Jon

zhendongzhang Tue, 03/06/2007 - 17:16
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Thanks all,I knew now.Thanks you. Here is my step for get port on htat switch.


1.查找高流量的IP 地址


sh ip cache flow



2.根据IP 地址查switch 上的端口

sALCNshg01#ping 10.35.3.43


Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.35.3.43, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/202/1004 ms

sALCNshg01#show arp | include 10.35.3.43

Internet 10.35.3.43 0 0011.85ea.2e2d ARPA VLAN100

sALCNshg01#show mac address 0011.85ea.2e2d

Non-static Address Table:

Destination Address Address Type VLAN Destination Port

------------------- ------------ ---- --------------------

0011.85ea.2e2d Dynamic 100 FastEthernet0/41

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