Date: Thu, 24 May 2012 09:43:21 +0200 (CEST) From: sthaug@nethelp.no To: rizzo@iet.unipi.it Cc: net@freebsd.org Subject: Re: use of non-contiguous masks in address lookups ? Message-ID: <20120524.094321.74735847.sthaug@nethelp.no> In-Reply-To: <20120524071055.GA50710@onelab2.iet.unipi.it> References: <20120524071055.GA50710@onelab2.iet.unipi.it>
next in thread | previous in thread | raw e-mail | index | archive | help
> every now and then the issue comes up on whether we still need > to support non-contiguous masks in address lookups. > I seem to remember someone (perhaps on this list) making a > case for their presence, but forgot the details. > So, does anyone know of a practical use of non contiguous masks ? I vote for removing non-contiguous masks. They are incompatible with CIDR, which was introduced in 1993 (!). Non-contiguous masks have been unsupported in many routers produced the last 10 years or so. E.g. for Juniper M/MX/T routers you specify an interface address with a contiguous mask (1.2.3.4/29 etc). It is *not possible* to specify a non-contiguous mask. Address lookup is always based on longest prefix match. Steinar Haug, Nethelp consulting, sthaug@nethelp.no
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120524.094321.74735847.sthaug>