see bug 56603. This package has been in portage since 2004. It does not appear to have ever had a maintainer, and 1.5 and 1.6 are going to require massive ebuild rewrites to fix some very nasty sandbox issues. (The ./configure script tries to START net-snmp on the system). I'm going to try to fix it in spare time but right now it has no reason to be in teh tree.
*** This bug has been marked as a duplicate of bug 263774 ***