Unfortunately, lftp prefers IPv4 over IPv6 by default. I would like to see Fedora modifying /etc/lftp.conf with the following line: set dns:order "inet6 inet" This reverts the order and lets lftp prefer IPv6 if available.
There is the 'dns:order' boolean .lftprc configuration variable for this purpose. Putting the line: 'set dns:order inet6 inet' in the lftp configuration file should do the trick - ie. in either the system-wide /etc/lftp.conf or the per-user ~/.lftp/rc or ~/.lftprc . You could also put the 'options inet6' statement in /etc/resolv.conf or rebuild the lftp package with the '-DINET6' option to achieve the same effect. This should not be the default setting, as most systems still use IPv4 first by default, and the 'inet inet6' default order is as documented in the lftp man-pages. Changing the default order would confuse and annoy many lftp users and make our lftp distribution different from all others.
Of course there is "dns:order", as I wrote in my original report. Regarding "most systems still use IPv4 first by default", this is just outright wrong. In dual stack systems, IPv6 is to be used by default, not IPv4. And actually I haven't seen it implemented the other way before, except in lftp. Anyway, the upstream author of lftp understood and fixed it for the next lftp version, so Fedora will have that fixed with the next lftp update too.