Want to ping a host using different source ip

[umar420e]

I made an ip packet using raw sockets and used icmp header of echo request inside that ip packet.I have a wifi lan with 2 host(laptops) connected to it. when I send the packets to any of these host the reply me with echo reply as i see in wireshark. but when i change the source ip and mac to that of another host there is no echo reply packet in the network but only echo request packet is there. Can anybody tell me why is this happening. and am also using Promiscuous mode so non of the packet is discarding.

[Rubberman]

Trying to build a forgeable DDOS tool? That's the only reason I can think of to forge the souce IP of a ping packet. So, please explain in detail what you are trying to do, and why?

[umar420e]

well i am not that big programmer to build hacking tools.I am a student interested in computer networking and want to see how protocols work and working of linux system. I was learning the programming of raw sockets and playing with them. Maybe one day I can invent a new protocol . I was jucst checking that is it possible that by changing the source ip we can send reply to different host. I searched whole internet was did not find a single article about it.

[Rubberman]

You can do that, reply to a different host. However, if it doesn't have an application waiting for a reply message, it probably won't do anything except drop the packet in the bit-bucket. As for TCP/IP protocols, those are spelled out in great detail in the DDN Protocol Handbooks, published by the US Department of Defense. You can create your own protocols for Ethernet (LAN only), or high-level (application level) protocols that are layered on top of the TCP/IP protocols.