layer 2 issue

[Silviu Lavric]

I have a frame with dest mac A getting to gateway which has a mac of B. How is that possible. Mac A is the mac of a device present on LAN. Question is how does the frame get to gateway using a different dest mac than the gateway's mac.

[Joseph W. Doherty]

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Posting

It's a unicast MAC?  If so, could it have been unicast flooded?  Or, SPAN isn't configured, is it?

[Silviu Lavric]

It is Unicast. No SPAN configured. Plenty of mac room and also all macs involved are correctly in mac table of the switch (N6k) with corresponding interfaces. IG bit and LG bit both 0. What else can I check ?

[cchamorr]

Is MAC A a directly connected device to the same switch? If no, what is the topology?

[ajaskowiec]

Could it be that there is a standby ip configured, at example HSRP or VRRP protocol?

In this case the destination MAC to the Gateway would be a virtual MAC of the protocol and not the Interface MAC of the Gateway.