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New Member

port ip

When auditing a switch to determine if a vlan is being used, or needs to be present, i can do a "sh vlan brief" to see what ports are assigned to what vlan.  what I would like to see more is when a switchport is active in a vlan, how can i retrive the IP address associated with that port.  ie..if port fa0/44 is connected and assigned to vlan800, how can I then find the IP that is using that switch port.


port ip


a port on a switch can't have an IP address unless it is a L3 port( with no switchport command), the only interface having an IP on a switch can be a SVI or Vlan interface or a loopback address.If it is a Vlan interface then it has the same  vlan id and then all trunk ports with this vlan not pruned or every interface in access mode in this vlan can use this IP if the switch is doing inter vlan routing.



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port ip


for layer 2: you assign IP address to the created vlans in your swtich vlan database. by then you may assign the required ports to the specific vlans ans this is depending on your requiredment. also you can creat many vlans in your switch.

for Layer 3 you can directly assign the IP address to the interface that connected to the different networks, LAN/WAN.

please let me know if this is not cleare.


New Member

port ip

I think you can use show mac-address-table on your switch and then notic the mac address which is learned on that port (For example Port Fa 0/44), After that you can use show arp in order to understand the IP Address that is using Port Fa 0/44. That's it.

port ip


Like they said a switchport doesn't have ip addresses. Then any of the ports in the show vlan will have an ip address, Now if you have a port in vlan 800, and you know what is the network address for vlan 800 you may guess that the host connected to that switchport is within the range of available ip addresses.

If you want to see what ip address are assinged locally to your switch, then run the command

"Show ip interface br | ex una"

"Show ip alias"


Wilson B.

New Member

port ip

Hey p-allen,

Try this and see if it works for you.

Getting the IP Address of devices connected to a Layer 2 switch (C2960 & C3750).

conf t

ip device tracking

interface range g1/0/1 - 48

ip device tracking max 10


---- Wait for approximately 10 seconds ----

sh ip device tracking interface