02-27-2006 07:11 AM - edited 03-03-2019 11:52 AM
Data Communications and Networking 3ed by Forouzan page 518 says:
[[[Case 2 :
The sender is a host and wants to send a packet to another hosts on another network. In this case, the host looks at its routing table and finds the ip address of the next hop (router) for this destination. The ip address of the router becomes the ip address that must be mapped to a physical address]]].
See the link below for case 2
http://img45.imageshack.us/img45/3345/case020vv.jpg
1- Shouldnt he say that : The mac address of the router becomes the mac address that must be mapped to the ip address instead of "The ip address of the router becomes the ip address that must be mapped to a physical address" ?
comparing with the link below:
http://www.cisco.com/warp/public/105/5.html
[[[Note: Multiple IP addresses are mapped to a single MAC address (the router's MAC address), indicating that proxy ARP is in use]]].
2- Target MAC address within ARP request packet is all 0s, this ARP packet is encapsulated directly inot data link frame.
MAC address for the same Target within data link farme is all Fs.
The same book depicts the MAC address within data link frame all 1s,,,Is this acceptable ?
Solved! Go to Solution.
02-27-2006 08:37 AM
Hi Zillah,
1) You are right saying that when we say proxy arp someone else in the network send its own mac address to map the destination ip address which does not belong to the one who send its mac address.
So your statement Shouldnt he say that : The mac address of the router becomes the mac address that must be mapped to the ip address" is true.
2) The destination address of the ARP is a broadcast address which is all 1's
http://www.erg.abdn.ac.uk/users/gorry/course/inet-pages/arp.html
But even if we say all F instead of all 1 in broadcast mac address it is one of the same thing
http://www.webopedia.com/TERM/B/broadcast_address.html
http://www.bellevuelinux.org/broadcast_address.html
So what I want to say is broadcast mac address can be represented by both the ways all 1's or all F's.
HTH, if yes please rate the post.
Ankur
02-27-2006 08:37 AM
Hi Zillah,
1) You are right saying that when we say proxy arp someone else in the network send its own mac address to map the destination ip address which does not belong to the one who send its mac address.
So your statement Shouldnt he say that : The mac address of the router becomes the mac address that must be mapped to the ip address" is true.
2) The destination address of the ARP is a broadcast address which is all 1's
http://www.erg.abdn.ac.uk/users/gorry/course/inet-pages/arp.html
But even if we say all F instead of all 1 in broadcast mac address it is one of the same thing
http://www.webopedia.com/TERM/B/broadcast_address.html
http://www.bellevuelinux.org/broadcast_address.html
So what I want to say is broadcast mac address can be represented by both the ways all 1's or all F's.
HTH, if yes please rate the post.
Ankur
02-27-2006 11:37 PM
Thanks Ankur
[[[So your statement Shouldnt he say that : The mac address of the router becomes the mac address that must be mapped to the ip address" is true.]]]
Does that mean there is a sort of typo in the explaination of the book ?
02-28-2006 12:12 AM
HI Zillah,
Yes there can be a type error in the book.
In proxy ARP the mac address of the router becomes the mac address that must be mapped to the destination ip address which is not in my network.
HTH, if yes please rate the post.
Ankur
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