My situation is that I want to modify all incoming UDP traffic going to a specific port so that the source IP appears to be from the local network. I completely realise this creates a problem as far as monitoring traffic goes, but that is unimportant at this point. Being on the same machine, I have found I cannot use the nat table, so SNAT and MASQUERADE are not available to me. Any suggestions on a fast and efficient way to pull this off?
