How to see ip details in switch

pramod.prasad · ‎01-31-2007

How we can saw which ip is connected to which port which mac address. through sh arp we can got the details of ip ,mac and vlan details but not the port.

vijayasankar · ‎01-31-2007

Hi Pramod,

What switch is this?

Running is what mode? layer 3 or layer 2.

If the switch is running in l2 mode, you wont be able to see any arps for the client PC on user vlans.

If it is running in L3 mode and if you have SVI's configured, show ip arp will provide you the ip to mac mappings which it had learned on the vlans.

Only the SVI interface is ip enabled, and hence only it can see the ip layer.

The switch port to which the host is connected is just a l2 connectivity to the PC.So this switch port can only learn the mac-address of the end host connected to it. It cannot handle/interpret the ARP messages.

If you want to further see where that ip host is connected you have to use the show mac-address-table command to trace where it is located.

If you have an ethernet port on the switch which is running in l3 mode, then you will be able to see the ARP mappings of the end host(s)connected to this port.

Hope this clarifies.

-VJ

pramod.prasad · ‎02-01-2007

we want port details,mac details and ip-details at same time .

pieterddejong · ‎02-01-2007

Hi,

Not sure of command that gives all these details. You would have to use "show arp", get the associated mac address for that IP and then use "show mac-addr | incl " to see the port. If running Catos use "show cam dynamic" to see mac addresses.

Regards

Pieter