1. In network network protocols, source routing is the capability whereby the sender can specify the route a packet should take. Analogy: Somebody asks you how to get to the freeway. You can give them two responses: You tell them to drive a little further on, and there will be signs pointing to the freeway. You tell them just to follow the signs. This is normal routing: you simply hand the packet off to the routers, and let them worry about which direction the packet takes. You tell them to drive up 3 blocks, turn left, then go 2 blocks, then turn right, then go one more block and bear left onto the onramp. This is source routing: you tell the packet every hop it should take through the network. Key point: The hacker can give the packets routes that go around firewalls. From Hacking-Lexicon