What happens when ARP Request comes from a different subnet?

Posted by gsinha on Server Fault See other posts from Server Fault or by gsinha
Published on 2012-06-10T15:20:27Z Indexed on 2012/06/10 16:41 UTC
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ip

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ethernet

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arp

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icmp

What will happen when an ARP Request packet is sent from router1 to router2 in the following two cases? Will an ARP Reply be generated or the ARP Request packet be dropped?

[router1]Intf1(20.0.0.1/24) ======== (40.0.0.1/24)Intf2[router2]
[router1]Intf1(20.0.0.1/24) ======== (20.0.0.2/8) Intf2[router2]

The topology above have a port "Intf1" on router "router1" connected a port "Intf2" on another router "router2" via a direct link(eg, a 1 Gbps cable).

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