Editing Tcp/ip packets

capture, view, monitor, yes, edit then resend not sure if that's possible. With IP, if a packet is not received promptly by the recieving computer, then the sending computer will resend the missing packets. By the time you modify the packet, I think that packet will already be retransmitted!?
 
capture, view, monitor, yes, edit then resend not sure if that's possible. With IP, if a packet is not received promptly by the recieving computer, then the sending computer will resend the missing packets. By the time you modify the packet, I think that packet will already be retransmitted!?
Without getting into semantics about what it means to "edit" but rather to simply look at it from a blackbox perspective, it is possible to "edit" packets in realtime. Consider a hardware router/IDS setup:
  • Suppose a user wishes to send a packet from 192.168.1.50 to 206.24.222.210
  • Device (192.168.1.1) recieves a packet
  • The NAT stuff fires up and notes that the destionation and creates a new packet with the destination of 206.24.222.210. Naturally this all happens within the TTL window
  • New packet is sent out. Granted this isnt "editing" an existing packet but as far as the both endpoints are concerned, it effectively is so (gosh this is starting to sound like String Theory)

Granted this is a very weak counter example and relies on (a) hardware level support and (b) you cant arbitrarily change anything which i believe was the original intent of the question, it is, in effect, an alteration of a packet
 
yah, I suppose if your a code warrior, and you know a lot about it, you could possibly interject your own little tidbits into the firmware of a NAT capable device?... (and go to federal prison for 10 years once you use it and get caught).

Honestly, this is a bit deep for me! I'll stopping now...
 
(and go to federal prison for 10 years once you use it and get caught).
Depends on how far you go with it. Im pretty sure making your own router (say via a FPGA+HDL) for running a home network is not illegal (nor even illegal if you use it to communicate outside of the home network ... i assume so long as you abide by FCC regs) ... but yeah, my scenario is a bit of a stretch :P
 
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