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New Member

sh arp

when given sh arp will it should show all the servers/machines arp resolution ?am able to see a few only wheras a lot are there..pls discuss..

4 REPLIES
New Member

Re: sh arp

Devices on a LAN learn about other devices by one of three ways:

1. They need to send a packet to that device for the first time.

2. Another device sends an ARP request to them.

3. Another device sends a gratuitous ARP.

To answer your question, yes, it is possible (and maybe likely) that devices exist on a LAN without being and a particular devices ARP cache. (Layer two switches are a good example, as they rarely need layer 3 communication to devices other than their default gateway).

Re: sh arp

If this is a layer-2 switch, then this is normal. A layer-2 switch does not participate in the layer-3 communication between servers, and so does not need the servers in its ARP cache. In fact, the only hosts that you will see in the ARP cache are the ones that have been talking directly to (as opposed to through) the switch.

Kevin Dorrell

Luxembourg

New Member

Re: sh arp

but even on L3 6513 am able to se only the directly connected interface's arp...

New Member

Re: sh arp

in order to see MAC of the desired device in the arp table, you'll need to ping (or something similar) it first.

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