I had a heck of a time a few years back trying to troubleshoot an issue where an upstream provider had an ACL with an incorrect mask along the lines of 255.252.255.0. That was really interesting to talk about once we discovered it, though it caused some loss of hair beforehand... -----Original Message----- From: NANOG <nanog-bounces+philip.loenneker=tasmanet.com.au@nanog.org> On Behalf Of Grant Taylor via NANOG Sent: Wednesday, 19 December 2018 10:27 AM To: nanog@nanog.org Subject: Re: Stupid Question maybe? On 12/18/2018 03:12 PM, David Edelman wrote:
I seem to remember that before the advent of VLSM and CIDR there was no requirement for the 1 bits in the netmask to be contiguous with no intervening 0 bits and there was always someone who tested it out on a production network just to prove a point (usually only once)
I would love to hear some confirmation of this, or even first hand experience. /Mainly/ for historical / trivial purposes. (Don't ask, don't tell.) -- Grant. . . . unix || die