From owner-freebsd-isp Sun Dec 9 4:45:45 2001 Delivered-To: freebsd-isp@freebsd.org Received: from velvet.sensation.net.au (vn.sensation.net.au [203.20.114.246]) by hub.freebsd.org (Postfix) with ESMTP id E37E137B416 for ; Sun, 9 Dec 2001 04:45:40 -0800 (PST) Received: from localhost (rowan@localhost) by velvet.sensation.net.au (8.9.3/8.9.3) with ESMTP id XAA45417 for ; Sun, 9 Dec 2001 23:45:38 +1100 (EST) (envelope-from rowan@sensation.net.au) X-Authentication-Warning: velvet.sensation.net.au: rowan owned process doing -bs Date: Sun, 9 Dec 2001 23:45:38 +1100 (EST) From: Rowan Crowe To: freebsd-isp@freebsd.org Subject: Re: arplookup In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Sun, 9 Dec 2001, Jim Weeks wrote: > Right now it is set to 255.255.255.0. I will try changing it as soon as > someone is physically in the NOC. I suggested doing this, but the admin > at the ISP insisted 255.255.255.0 was necessary. I guess I should have > tried it any way. Just a warning that this will break connectivity to IPs in that block of 65535 IPs that are *not* on that LAN. For example, if your IP is 1.1.100.3 and your netmask is 255.255.255.0, your LAN has 255 local hosts, and everything else is routed via the gateway. If you change it to 255.255.0.0, then your LAN has 65535 local hosts, and everything else is routed via the gateway. This means that if you try to communicate with (say) 1.1.200.1, it will fail, because your machine assumes it's on the LAN, when it's *really* outside of that network, and can only be reached via the gateway. Coming full circle, setting that hostmask may actually cause similar or identical ARP errors on other machines, because there will be ARP requests coming from your machine for IPs that *are not* on the LAN (but your machine thinks they are) Cheers. -- Rowan Crowe - Melbourne, Australia www.camrecord.com | www.camdiscover.com | www.sensationbot.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message