I have a few questions regarding IPv4 and IPv6 spoofing. Might as well just list them to be concise:
- What's the usual routing policy for ISPs' routers in regards to spoofed source addresses? i.e. if an ISP's router manages the 123.123.123.xxx /24 block and a machine sends it a packet claiming to be from 220.127.116.11, does it still route the packet?
- Normally packets from within a subnet are translated to an external IP when they pass through a NAT router. Are there any methods that someone might use to forge the internet-side source address when sending a packet through such a router?
- Does IPv6 offer any mechanism or changes that mitigate (or perhaps create) such issues?