On 2017-12-06 13:14, OB1 oldbasford@... [firebird-support]
wrote:

> We're making the jump from v1.56 to v3.0.2 (gulp!) and to make the
> transition easier for our clients we wondered if v3 client libs
> (fbclient.dll) can access 1.56 servers. We've tested this and it
> appears to work, but wanted to confirm if it was officially supported.

Technically yes, the wire protocol is versioned and fbclient.dll of
Firebird 3 supports the older versions of the protocol (if it didn't you
wouldn't even be able to connect with older versions of the protocol).
However given that Firebird 2.1 and older are no longer supported, I'd
say that 'officially' it isn't ;).

Mark