Solved

When do IP's show up in the SHOW ARP command?

Posted on 2008-10-22
7
1,591 Views
Last Modified: 2008-10-22
I do not fully understand when an IP address will show up in the output of the SHOW ARP command.  For example, I have a VLAN on my CISCO 4006 Switch and I know there 4 dell PC's are connected to it.  I thought that the IP's for those PC's would show up in the output of a SHOW ARP command so I could then get the MAC addresses of those PC's, run a SHOW MAC ADDRESS command, and find the port they are connected to.  However, even though these PC's have been connected for quite some time, their IP addresses do not appear when I run a SHOW ARP command.  
0
Comment
Question by:frank_nye
  • 3
  • 2
  • 2
7 Comments
 
LVL 20

Accepted Solution

by:
RPPreacher earned 50 total points
ID: 22775831
When something makes an ARP request to them.

Just ping each PC, the switch should populate the ARP table.
0
 
LVL 7

Expert Comment

by:knightfox
ID: 22775847
that correct.. you should be able to do a show arp.  Could you please try and ping one of the IP addresses then run:

Router#sh ip arp
Internet  x.x.x.x             -   000b.fc48.xxx  ARPA   Vlanxxx
Internet  x.x.x.x             -   000b.fc48.xxx  ARPA   Vlanxxx
Internet  x.x.x.x             -   000b.fc48.xxxx  ARPA   Vlanxxx
Internet  x.x.x.x             -   000b.fc48.xxx  ARPA   Vlanxxx

/Fox

0
 
LVL 7

Expert Comment

by:knightfox
ID: 22775864
then to show the port do:

Router#sh mac-address table | i xxxx

xxx is the last four chars of the mac address... and you should see

 xxx    0000.0c07.xxx    DYNAMIC    Gi0/1

/Fox
0
VMware Disaster Recovery and Data Protection

In this expert guide, you’ll learn about the components of a Modern Data Center. You will use cases for the value-added capabilities of Veeam®, including combining backup and replication for VMware disaster recovery and using replication for data center migration.

 

Author Comment

by:frank_nye
ID: 22775947
If I do a PING command while in ENABLE mode on the switch, does it start a ping and continually run it or does it just send out a few pings and then stop?  On some devices (I think some test equipment like a Fluke Etherscope) I have seen a PING request go out and then it just keeps on running and runing.  I want to make sure I don't start something like that on the Switch.  If I just run the command PING 10.0.4.20 on the switch, will it only send out a few pings?
0
 
LVL 20

Expert Comment

by:RPPreacher
ID: 22775967
5 pings.
0
 
LVL 7

Expert Comment

by:knightfox
ID: 22775990
you can do it either ping.. and enter the number of pings you want.. or just use ping x.x.x.x and use

CTRL + Shift + 6 to escape the ping

/Fox
0
 

Author Comment

by:frank_nye
ID: 22776155
Thanks everyone.  I got it.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Download Logs File from Cisco Switch 1 46
policy routing to fw2 18 67
Switch Migration 8 49
Dell Powerconnect Switch lost username/password 2 41
 One of the main issues with network wires is that you never have enough.  You run plenty and plan for the worst case but you still end up needing more.  What many people do not realize is with 10BaseT and 100BaseT (but not 1000BaseT) networks you …
Hi there, This article summarizes what you need if you are going to set up your home or small business Network Attached Storage (NAS) to be accessible from the internet. Of course there are configuration differences based on your NAS or router ma…
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
The Email Laundry PDF encryption service allows companies to send confidential encrypted  emails to anybody. The PDF document can also contain attachments that are embedded in the encrypted PDF. The password is randomly generated by The Email Laundr…

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question