Where is the ARP table for switch vlan?

I have a network with a lot of vlans and interface vlans are configured on various switches. There is 1 VTP server, but I can't always find a mac on the server, I'm wondering where/what switch I need to do the sh arp on to find a mac-address for a specific vlan subnet device?


Thank you,
Dave
dsterlingAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

pjwallisCommented:
Hi,

I would run the command "sh arp" on the switch that the computer is connected to. I assume you have a cisco network switch? There is a different command to run on the computer.

I did have an ARP issue on my core switch, yes it was just about everything connected to the switch when it played up, replacing the core switch with the older core switch confirmed the diagnosis and the core switch was replaced under it's lifetime warranty, which fixed the problem. This would be a rare occurrence but can you try another switch?

On the computer ( Microsoft Operating System ) check out http://technet.microsoft.com/en-us/library/cc786759(v=ws.10).aspx

Other network tools for use on the computer including how to flush the ARP cache http://technet.microsoft.com/en-us/library/cc757819(v=ws.10).aspx

pjwallis
0
Craig BeckCommented:
ARP is a Layer-3 (but somewhat broadcast-based) protocol.  If you want to find a MAC address for a particular IP address you will need to issue the show ip arp command on a switch which has an IP address on the same subnet as the machine you want to query.

So for example, if you issue the show ip arp command on a switch which only has a management IP address, unless the machine you're querying is on the management VLAN you'll not get a match.

If you go to the core switch or router and issue the command, as long as that router has an IP address on the same subnet you'll see an entry in the ARP table.

Basically the device you issue the command on must have an IP address in the subnet you're querying.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Switches / Hubs

From novice to tech pro — start learning today.