From owner-freebsd-questions Thu Sep 5 4:54:20 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A9C1F37B400 for ; Thu, 5 Sep 2002 04:54:17 -0700 (PDT) Received: from smtp.infracaninophile.co.uk (happy-idiot-talk.infracaninophile.co.uk [81.2.69.218]) by mx1.FreeBSD.org (Postfix) with ESMTP id C98AB43E6E for ; Thu, 5 Sep 2002 04:54:16 -0700 (PDT) (envelope-from m.seaman@infracaninophile.co.uk) Received: from happy-idiot-talk.infracaninophile.co.uk ([IPv6:::1]) by smtp.infracaninophile.co.uk (8.12.5/8.12.5) with ESMTP id g85BsGGk033330; Thu, 5 Sep 2002 12:54:16 +0100 (BST) (envelope-from matthew@happy-idiot-talk.infracaninophile.co.uk) Received: (from matthew@localhost) by happy-idiot-talk.infracaninophile.co.uk (8.12.5/8.12.5/Submit) id g85BsAC2033329; Thu, 5 Sep 2002 12:54:10 +0100 (BST) Date: Thu, 5 Sep 2002 12:54:10 +0100 From: Matthew Seaman To: Wayne Pascoe Cc: freebsd-questions@FreeBSD.ORG Subject: Re: IP Aliases in different subnets Message-ID: <20020905115410.GC32849@happy-idiot-talk.infracaninophi> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.1i Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, Sep 05, 2002 at 11:49:36AM +0000, Wayne Pascoe wrote: > I've got a question about IP aliases in different subnets. Since > around 4.5-RELEASE, the subnet mask of an IP alias is now supposed to > be 255.255.255.255. This is fine if all of the aliases are in the same > subnet as the primary IP address for the adaptor. > > My question is what happens if I have a primary address with a > different subnet mask to the alias? What should I be using as my > subnet mask for the alias in /etc/rc.conf > > For example: > Primary Address - 192.168.1.129 netmask 255.255.255.192 > First Alias - 192.168.1.193 netmask 255.255.255.224 That's correct. For each distinct subnet, the first IP address (whether a primary or alias address) thereon should use the appropriate netmask for each subnet. It's the second and subsequent aliases on a subnet that have to have the 255.255.255.255 netmask. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message