Date: Thu, 9 Aug 2001 12:47:56 -0400 From: Leo Bicknell <bicknell@ufp.org> To: hackers@FreeBSD.ORG Subject: Re: forwarding broadcast Message-ID: <20010809124756.A47552@ussenterprise.ufp.org> In-Reply-To: <20010809113638.A9519@enterprise.spock.org>; from jon@FreeBSD.ORG on Thu, Aug 09, 2001 at 11:36:38AM -0400 References: <20010809113638.A9519@enterprise.spock.org>
next in thread | previous in thread | raw e-mail | index | archive | help
This is called a 'directed broadcast'. In the early days there was no talk of this sort of packet, leading to the assumption that it should work as you expect. Many network management packages did (and some still do) use directed broadcast pings to try and find all hosts on managed subnets. Due mainly to smurf amplification (send a directed broadcast ping to a full subnet with a spoofed source to flood that box) ISP's (and more slowly) router vendors have turned this feature off in almost all Internet networks. The Cisco interface command is 'no ip directed-broadcast' on an interface. I would recomend strongly against ever turning it on, in any enviornment. That said, it does not seem unreasonable to provide the knob, since all major router vendors do and FreeBSD should be as flexable as any commercial product. -- Leo Bicknell - bicknell@ufp.org Systems Engineer - Internetworking Engineer - CCIE 3440 Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010809124756.A47552>