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New Member

ARP question

Hi,

I'm curious to find out what goes on as far as communications between a local host and a router is concerned when the arp cache of a router has two instances of the same MAC address but different IP address.

sho arp

...

Internet 172.20.20.2 2 0001.64ff.ce99 ARPA

Internet 172.20.20.3 3 0001.64ff.ce99 ARPA

Thanks,

Mavin

  • Other Network Infrastructure Subjects
3 REPLIES
Silver

Re: ARP question

most likely a firewall

New Member

Re: ARP question

I think communication will be fine as long as both IP addresses are on the same system.

I have come across this kind of scenario on SUN platform using a Quad Card, which could use same MAC address for all 4 interfaces. OR 2 IP addresses binded to single physical interface. In my understanding, for packet destined to either IP address, router will forward the packets with destination MAC address of 0001.64ff.ce99.

Bronze

Re: ARP question

Around here they do it on their UNIX hosts with "alias" addresses. It could be any of the above. Do you know what the mac address is?

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