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layer 2 broadcast/secondary address

I have a VLAN with 4 subnets - 3 secondary IP addresses. When one workstation sends a broadcast to, it builds a layer 2 mac header with destination address ffffffff.

Every workstation in the VLAN will get the layer 2 packet, across all subnets - correct?

Every workstation will process the packet as far as layer 2 - correct?

When they strip away the layer 2 info, they will see the destination ip address of - and then only devices in that subnet will process it further - correct?

If the application generates a then every machine will process the packet at layer 3 and above?

What does "Broadcast address is" mean when you do a "show ip int" on a router?

Thanks for the help. A lot of this is probably obvious


Re: layer 2 broadcast/secondary address

All your answers are Yes!

Broadcast address is means that if your router int has an ip address of and if you want to send a broadcast to your all hosts in that network, the router by default will send a broadcast not to but to

So, on the interface if you give the command "ip broadcast-address ", the router will now display "Broadcast address is" under sh ip int and send broadcast to this address only, not anymore.


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Re: layer 2 broadcast/secondary address

Thaks for that.

Just to clarify:-

-my VLAN with 4 subnet addresses (a primary with 3 secondary's)

-when a machine on one of these subnets sends a broadcast the router hears it

-then, because it is configured with Broadcast address is - it will send (or resend even??) the broadcast that it heard to - so all devices in all subnets will receive it? The entire VLAN.

-Or, does the router have to originate the broadcast - but they don't do this?

-Or, does the specific application on the workstation have to generate the or

Routers do not forward - correct?

Routers will forward - directed broadcast - (if enabled) correct?

Sorry if they are confusing or obvious

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