how "arp" works in this case

AdNet

Hi lads,
I have this question below on my homework
any hints or answers

"A PC has the following IP config
Address: 10.1.2.99
Subnet Mask: 255.255.255.0
Default gateway 10.1.2.1

When the PC pings (i) 10.1.2.40 (ii) 10.1.1.2,
what address does must it reolve via ARP in each of these cases?"

Thanks

Webmonkey

Have you made any attempt to work this out?

If you do any bit of research on ARP you will realize it's only required for destinations on the same network and something else that should be obvious if the destination is on another network. That should be enough for you.

William Powell

Best hint I can give you is that once you know how arp works you'll see its quite a good question to test your knowledge of how arp works.

You might also need to know the relevace of the Default Gateway if you don't you won't be able to answer the question.

AdNet

Problem I have is my english
I have a problems with 'understanding' it when i'm reading or writing... sounds bad , he?

So the answer will be that it will work OK with (i) but it must have some more trafic to reach (ii) or what?
Gateway in case (i) is the same, so network is the same - only different "PC" so ping will work...
case (ii) ping will not work or...? what?

Yes I did research but still have some problems to understood how it works...

swampgas

AdNet wrote: »

Problem I have is my english
I have a problems with 'understanding' it when i'm reading or writing... sounds bad , he?

So the answer will be that it will work OK with (i) but it must have some more trafic to reach (ii) or what?
Gateway in case (i) is the same, so network is the same - only different "PC" so ping will work...
case (ii) ping will not work or...? what?

Yes I did research but still have some problems to understood how it works...

A subnet is a group of network interfaces that can talk to each other directly, using MAC addresses to pass messages. ARP allows one network interface on a subnet to discover the MAC of another interface on the same subnet so it can start talking to it directly.

If the IP you want to talk to is on another subnet, you can't talk to it directly using MAC addresses. You need a router to relay the messages for you - this is your gateway, and it has to be in your subnet. So you talk to the gateway, using its MAC address, using the IP address of the actual destination.

I really hope whoever is teaching you this stuff can draw you a picture ...

AdNet

swampgas wrote: »

I really hope whoever is teaching you this stuff can draw you a picture ...

Love asnwers like that "Like"
Yes! I do have video how it works just could not understood question realy good.

So I gues the answer will be:

ping must resolve (i) just MAC in the same network
(ii) just MAC on gateway

right?

Webmonkey

AdNet wrote: »

Love asnwers like that "Like"
Yes! I do have video how it works just could not understood question realy good.

So I gues the answer will be:

ping must resolve (i) just MAC in the same network
(ii) just MAC on gateway

right?

Bingo

i) MAC associated withthe IP on the same network
ii) MAC of the router interface (default gateway)

AdNet

Uff

it's only a start and it's not going easy
Ta a lot for help, again.
Adam