From owner-freebsd-questions@FreeBSD.ORG Wed Nov 1 20:53:51 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org 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 358FB16A403 for ; Wed, 1 Nov 2006 20:53:51 +0000 (UTC) (envelope-from af300wsm@gmail.com) Received: from py-out-1112.google.com (py-out-1112.google.com [64.233.166.180]) by mx1.FreeBSD.org (Postfix) with ESMTP id DF80943D81 for ; Wed, 1 Nov 2006 20:53:43 +0000 (GMT) (envelope-from af300wsm@gmail.com) Received: by py-out-1112.google.com with SMTP id z59so254999pyg for ; Wed, 01 Nov 2006 12:53:10 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type; b=N9oaz9uuFO8RxCZ4q/S+eb/ZFJirB9Y1X/A9XqbmH7GcsV5gN1pbQDq1RqIzOSXIfG4yESQq7RsuUP6HiZ8gGRoh0BWEKMxNgupJCjDMjoy+Sqdd+Xy1J5rPFElPuhS401gVzg19BSftfp0a6BcFDFkfWzP6FSkA88IWAIb0ll4= Received: by 10.35.80.20 with SMTP id h20mr10763951pyl; Wed, 01 Nov 2006 12:53:09 -0800 (PST) Received: by 10.35.121.10 with HTTP; Wed, 1 Nov 2006 12:53:09 -0800 (PST) Message-ID: <340a29540611011253r1bb00f65sfc76760a7aea5036@mail.gmail.com> Date: Wed, 1 Nov 2006 13:53:09 -0700 From: "Andrew Falanga" To: freebsd-questions MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Need some assistance with IPv6 addresses X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 Nov 2006 20:53:51 -0000 Hi, At work I have a FreeBSD machine that I use for various testing and I need to setup an IPv6 only LAN using this machine. To this end, I have a few questions. 1) How can I remove an address from an interface using ifconfig (or other utility)? That is, I want to remove all IPv6 addresses this system might already have (except of course the link-local address fe80) and create new ones the fly and I don't want to reboot every single time. 2) Second, how, exactly, does the prefix length figure into things. I am reading up on IPv6 using various sources such as RFC's and the Handbook and what it says about IPv6, but when I assigned an address of fec0/10 (mentioned in the handbook) I can't ping the other system I assigned the same address to. In the handbook, I noticed that it linked to RFC 3513 and in that RFC it specifies the following: Site-Local addresses have the following format: | 10 | | bits | 54 bits | 64 bits | +----------------+-------------------------+----------------------------+ |1111111011| subnet ID | interface ID | +----------------+-------------------------+----------------------------+ Which is fec0:: >From the above, I'd assume that the prefix length should be /64. But this is assuming that my understanding of the prefix length is correct in that it is synonimous with the subnet mask in IPv4. This is what I originally thought, but thought I might be incorrect when I read in the handbook that the prefix length for fec0 is /10. So, on my FreeBSD system I did this (after a reboot, which I'd really rather avoid): ifconfig sis0 inet6 fec0:1:1:1::1/10 I can ping this address but not the other system I configured like this with fec0:1:1:1::2/10. So, where is my error in IPv6? Second, how do I remove previous IP addresses from an interface with rebooting? Andy