01-09-2019 11:00 PM
Hello,
Let's say interface descriptions are not used and show lldp/cdp neighbors are completely disabled on neighboring devices shown below. And you login to the middle switch, how would you know your neighbors?
Router<-------->Switch<-------->Switch
Many thanks in advance for your response!
01-09-2019 11:27 PM
01-10-2019 11:24 PM
Thanks for the response. Can you tell me how I can use OUI lookup?
01-11-2019 02:33 AM
01-12-2019 10:37 AM
Using the arp table is an interesting suggestion and is one of the first things that I thought of. But we can not be sure that there will be entries in the arp table for both neighbors. There will be arp entries only is there has been successful layer 3 IP communication from the switch management interface address to each of the neighbors. Of course there is an advantage in looking into the arp table to find the neighbor. If there is an entry then we know not only the mac address of the neighbor but also know the IP address.
But an OUI lookup is possible even if there are not arp entries. Looking into the switch mac address table will provide the mac address of each neighbor device.
HTH
Rick
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