ethernet and ip headers

[carl_townshend]

Hi all, i know this is a very basic question, but can anyone tell me what the ethernet header is, and what it contains and used for, and also the same for the ip header ?

[royalblues]

Have a look here

http://www.wildpackets.com/support/compendium/manual_appendices/nxA1_packets

You should get all these details by googling on the internet :-)

Narayan

[carl_townshend]

when the router receives the packet and needs to forward it, I have seen that it needs to rebuild the header, is this the layer 2 ethernet header, ie next hop mac address ?

[royalblues]

The header would differ based on the connection the router has..

If the router needs to forward a packet out its interface which is serial, then it would build a HDLC or PPP header, similarly FR header for frame-relay. If it is ethernet, then it would be a ethernet header with the next-hop mac addresss as the destination MAC

Narayan