Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Problem in Cisco 3550

Guys....i have a v simple problem i shd i guessed it but i m helpless......i m so dissappointed with my self that spending 7 years in cisco industry i forget commands all the time :-( i have a pc connected to a swicth (3550) now i have given a pc an address (suppose) now when i see the mac-address i give command sh mac-address table int fa0/1.....but when i give the command on cisco switch to find the ip adress from mac its showing nothing......i put sh ip arp | inc x.x.x.x (mac) but it doesnt show anything.......guys all th einterfaces are in vlan 1 and there is no vlan interface definded on swucth either.........second stupid problem is when ever i want to redo the command i press arrow button but it gives me ^@ this error all teh time i have to retype the command all teh time again and again

plz help me out...........and thanks for looking

Cisco Employee

Re: Problem in Cisco 3550

The Guroo,

You will only see the PC's MAC address in the ARP table only when you ping the PC from the switch or vice-versa. I.e the traffic destined to or originated from the switch will make the ARP table to be populated.

For your second problem, I think you can use ctrl+p to see the previous command.

Please see the link below for more command refrence:

HTH,Please rate if it does.

-amit singh


Re: Problem in Cisco 3550


Whether the port where you connected the PC is up or down. If it is up you should normally see th mac-address.

But to see the arp mapping, i don't think you can see on this switch because you are telling no SVIs been created for this vlan.

Next for the working of arrow button, pls. see whether the terminal editing is enabled or not. Because sometimes when editing is disabled you would find this problem.....

Router> terminal editing

Switch> editing

Rate if it does,


New Member

Re: Problem in Cisco 3550

The switch if it is acting as a layer 2 device then it will not see or record the ip address of the packet.So sh ip arp does not show any ip to mac mapping.

Try sh ip arp on the router if you have one connected in the same vlan.

For the redo command .. which software are you using to telnet ? Alternatively try Ctrl+P to access the previous commands and Ctrl+N to access the next command.

New Member

Re: Problem in Cisco 3550

I agree with balajit that you need to create a SVI (interface vlan)first and assign an ip address to it. Once the interface vlan is up, you can ping from your PC to the switch or vice-versa and then you would be able to see the arp.