Ping Issues connecting 2 PC

syed_khalid_khursheed · ‎10-04-2007

hi,

I have connected two pcs with a cross cable and provided the ip addresses as: PC1-->192.168.0.1/24 PC2-->192.168.0.2/16. For my surprise both pcs were able to ping. Same goes when I have a switch in between.

Any could explain this behavior would of great help.

Thanks in advance

Jon Marshall · ‎10-04-2007

Hi

PC1 wants to ping PC2

It compares the destination address of PC2 with it's subnet mask ie.

192.168.0.2 255.255.255.0 (it has to use it's own subnet mask as it doesn't know PC2's subnet mask).

So PC1 thinks PC2 network is 192.168.0 which is the same as it's own so it arps out, gets back the mac-address and sends the packet.

Now the other way around

PC2 wants to ping PC1.

PC2 does same as PC1 in previous example.

192.168.0.1 255.255.0.0

So PC2 thinks PC1 is on 192.168. which is the same netowrk as itself so it arps out, gets back the mac-address and sends the packet.

HTH

Jon

paul.matthews · ‎10-04-2007

There is no problem here for them talking to each other, as both addresses fall within the smaller subnet.