have you found a neat solution? proposed solution are cumbersome and are missing the whole ipv4 loopback magic.
I am really missing the multiple ip loopback capability on ipv4;
Such you can test application traffic ip handling running locally on the same sytem
knowing the whole 127.0.0.0/8 ip range is fully yours, not be worry about
outside interference, simulating multiple server working together.
My understanding ipv6 prefix fc00:: was doing the exact purpose, but was
scrapped by RFC3879, for concerns which still escape me...
