Unicat address

[zillah2004]

If I have got this scenario, router with 2 hubs each hub belongs to one LAN, with each LAN I have got 3 PCs.

ARP request is broadcast address, that mean each PC takes copy of ARP request frame to check it. Now with ARP reply which is unicast address, does each PC take copy of ARP reply frame to check it ? which I believe it should not do that because it unicast.

If it should not , how the PC can check that the ARP reply packet not intend for it ?

Also we have hub connected all the PCs to make our LAN1 and LAN2, and hub seperate the packet(can not control it)

[david.bradley]

each host processes the ARP to see if the frame contains it's IP address, the one that has the IP address replies to the sender direct with a unicast. All the other hosts drop the ARP request frame.

[zillah2004]

Thanks david

You did not get what I meant.

How can the PCs check that the ARP reply not for them ?

[zillah2004]

Any clue about this scenario

[drocher]

On a LAN, each host accept or deny the layer 2 frame based on destination MAC address. It will accept its own MAC address(es) and multicast addresses; with broadcast address being a special case of multicast addresses.

ARP request use a MAC broadcast address as destination MAC address.

ARP reply use the MAC 'unicast' address of the requester as destination MAC address.

[zillah2004]

Now with RARP it is same thing, RARP request is broadcast, and RARP reply is unicast.

Why does cisco say about RARP reply:

"All computers copy the frame and examine it".

The reason i am asking, for the unicast, they should not copy the frame, otherwise it will be same as broadcast!!!!

[zillah2004]

Any help about this issue