[pilom]

Much more common that malicious outages is malicious creation of ghost networks. Basically a person could say over BGP "W.X.Y.Z is at my office" where that address isn't used by anyone anywhere else on the internet. Then they do their bad deeds from that made up address. Lastly they remove their route via BGP and it is as if their addresses never existed.

[sounds]

That might work for some unused /24's for a large organization's /8 block, but unused IPv4 addresses are so last year!

I suppose the attack will still work for IPv6 for a long time.

[wmf]

There are a lot of IPv4 addresses that are assigned but not routed on the Internet, so you can easily "borrow" them. This kind of trick does leave a trace, though.