It looks like ftp://ftp.freebsd.org/pub/FreeBSD/ports/amd64/packages-9.0-release/Latest (or packages-9-stable) does exist any more. What's wrong?
Code:
pkg_add -r math/lp_solve
Error: Unable to get ftp://ftp.freebsd.org/pub/FreeBSD/ports/amd64/packages-9-stable/Latest/math/lp_solve.tbz:
File unavailable (e.g., file not found, no access)
pkg_add: unable to fetch 'ftp://ftp.freebsd.org/pub/FreeBSD/ports/amd64/packages-9-stable/Latest/math/lp_solve.tbz'
by URL