Broadcast MACC address

[rlarkins]

If I'm on 1000Base-TX Ethernet, and I want to send a unicast (UDP) frame with a Broadcast MAC address, how will the Cisco 6509(IOS) Gigabit Ethernet interface respond?

For example, take a /30 network between host and router, the host sends a unicast IPv4 packet to an off-net destination, but uses an all FF MACC address.

I'm not sure, but won't the switch/router accept the packet and perform the necessary layer 3 routing anyway?

TIA

-- Rich

[ehirsel]

I don't believe so. The interface will look at the packet, due to it being addressed to all end-stations, but then in looking at the ip header, realize that the frame is not inteded for it, so it most likely will drop it.

Is there a reason that you would use the broadcast mac address to send unicast frames?

[rlarkins]

Truthfully, Gig Ethernet interface software programmers that don't want to write classic ARP functionality code...

They actually had me run IRDP for awhile.

Thanks.

-- Rich