05-17-2023 04:37 AM - edited 05-17-2023 04:39 AM
Hi,
I have two Cisco Nexus switches that are configured with VPC in following topology:
What will happen in case the client will send a lot of broadcast packets from both of his links (load-sharing bond) that have the same source MAC address (e.g. 00:1b:12:34:45:78) to Cisco Nexus A and Cisco Nexus B member ports?
Cisco Nexus A will forward the broadcast packets to Cisco Nexus B via the peer-link, right?
If so, is MAC flapping expected to occur on Cisco Nexus B peer-link and VPC member port B?
Is it a problem? (e.g. log flooding, communication issues etc.)
Does VPC has a mechanism that prevents this MAC flapping? How?
Thanks,
Matan
05-17-2023 03:30 PM
why the NSK detect mac flapping ?
the MAC will add as following
VLAN-PO ""to clint"" -MAC
the NSK will not learn MAC through the peer-link, dont worry.
05-18-2023 12:17 AM - edited 05-18-2023 12:20 AM
What is NSK?
So MAC flapping will not occur?
Can you explain why the client MAC address will not be associated with the peer-link port even though a packet with the client source MAC was received by Cisco B peer link port?
The switch knows that member port B is up and is already associated with this MAC address and therefore will avoid re-associating the client MAC address to the peer-link port?
05-18-2023 07:41 AM
the NSK is mark any MAC address learn from Peer-Link for vPC VLAN with ""+"" this use as indication that this MAC is receive from NSK Peer and forward to this NSK via Peer-link.
there is no mac flapping
NSK meaning nexus
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