How defer ARP entries from mac-table in Frames (package) forwarding
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04-15-2015 10:26 AM - edited 03-07-2019 11:33 PM
Switches, dynamically speaking, change the port assign to a mac-address, but what happen if i have a router with multiple entries in the ip arp table. How can I predict the data flow. This usually happens in a DHCP environment with a short lease period?
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04-15-2015 10:41 AM
The question isnt very clear. ARP is the conversion from IP to MAC. If a host is communicating to another and has the correct IP of its peer on a segment, the mac address should become known in normal circumstances via ARP.
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04-15-2015 10:42 AM
I don't follow.
The arp table has the outgoing interface and this tells you which interface it will sent out.
Actually if the router is using CEF it will be adjacency table but it should still be sent out of the same interface.
Jon
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04-16-2015 01:40 AM
I am agree that the question is not clear, actually is a question that Cisco pretended me to answer it. In the output of the show arp in a router shows the same ip in multiple entries and 3 different ports numbers, different Mac-address, and ask me to predict how or to what port the router will forward the package. I been asking me the same question since I saw the question, I will like to have a good answer.
