I have read the RFC on this and can't seem to find what I am wanting to know. When implemented, if a client and a server support TLS fallback protection, does it only keep them from downgrading to SSLv3, or for example if the connection is made at TLS1.2, will it hold it there? Or will it allow it to fall back to 1.1 or 1.0?
TLS_FALLBACK_SCSV draft RFC protects against any downgrade attack. When a client's first handshake attempt fails and it falls back to a lower TLS version (including but not limited to SSL 3), it will include the SCSV, and the server can know that the client wants to support a higher version but was prevented from doing so. If the server also supports a higher version than the one the client fell back to, it will generate a fatal alert, since there should be no reason for the client to fall back below the server's highest-supported version.