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how to make sure a packet is sent out? 2

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cjiang

Programmer
Jan 25, 2006
2
US
i have a good internet connection and want to send out a packet: can be anything, or nothing in side the packet except a header.
the problem is: i ONLY send it to myself.
so, i have the same destination ip and source ip. i tried regular approach. the fact is: the packet has never been sent out.
thanks a ton.
 
Let me see if I understand correctly. The problem is that you want to send a packet to yourself, but you are not receiving any packet ?
 
I send out a packet to myself and I do receive it.
But, the packet never leaves the computer. In another word, the network card never sends out any packet that has the same destination IP and sourse IP.
How do I force a packet out of my computer and receives it like regular packets?
Thanks
 
I don't believe specifying your own source as destination or using loopback address won't put the packet on the wire. These are just methods to verify your IP stack is working properly and doesn't involve transmitting said packets.

Can you not just ping something remotely and look for the response packets to the ping?
 
If you send a packet to your own IP address, it will never make it all of the way down the IP stack. When it gets to Layer 3 (IP), it will check its ARP cache and determine that the IP address is local. Then it will pass the packet back up the stack to be received.

What are you trying to achieve? If you are just trying to put a packet out on your network that has the same source and destination address, there are a host of tools that will allow you to do this. They just can't be your IP address.


pansophic
 
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