I'm reading the 'Routing TCP/IP volume 1'. It says that the proxy arp is default on the cisco router. I got a cisco router and can't find any command relate to the proxy arp. Maybe is the problem of IOS version.
I made a test to find out how the router deal with packet it received. I clear the gateway on a computer , set a static arp of another network's IP with mac address is router's on the computer. Then I tried to ping that IP address but failed, the destination unreachable. So firstly the router hasn't got a proxy arp protocol running on. Secondly, the ping packet hasn't transported as I suppose. I need a sniffer to find out what happened. As I haven't got a suitable sniffer, let's just analyse it in theory.
The first possibility is the windows thinks that the destination IP is belong to another network while there is no gateway. So the windows sends nothing. In this case, I need send a packet manually.
The second possibility is the router received the packet but did nothing or just drop it. How dose the router working in this case? The physical connection is all right, so there is no problem in the layer 1. The router shall receive the packet in the layer 2 because the packet has the right mac address. In the layer 3, the packet has the right resource IP address that the receiving port can communicate with, the right destination IP address in the route map. Then why the ping packet can't been transport correctly?