From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= Subject: Re: How is IPv6 dhcp supposed to work? Date: Wed, 18 Jun 2014 12:37:37 +0200 Message-ID: <87ha3isdu6.fsf@nemi.mork.no> References: <53A0B617.6070600@candelatech.com> <1403044471.16272.20.camel@dcbw.local> <53A0CC31.6090707@candelatech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Dan Williams , netdev To: Ben Greear Return-path: Received: from canardo.mork.no ([148.122.252.1]:52315 "EHLO canardo.mork.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966142AbaFRKiA convert rfc822-to-8bit (ORCPT ); Wed, 18 Jun 2014 06:38:00 -0400 In-Reply-To: <53A0CC31.6090707@candelatech.com> (Ben Greear's message of "Tue, 17 Jun 2014 16:16:01 -0700") Sender: netdev-owner@vger.kernel.org List-ID: Ben Greear writes: > Does that router advert below look proper?=20 No, it doesn't. How did you create this? > I'm going printk diving in > the IPv6 stack in the meantime... > > > [root@simech2-f17x64 lanforge]# cat pkt.txt > No. Time Source Destination Proto= col Length Info > 34 229.636063 fe80::e4be:86ff:fe27:a33 ff02::1 IC= MPv6 110 Router Advertisement from e6:be:86:27:0a:33 > > Frame 34: 110 bytes on wire (880 bits), 110 bytes captured (880 bits) > Ethernet II, Src: e6:be:86:27:0a:33 (e6:be:86:27:0a:33), Dst: IPv6mca= st_00:00:00:01 (33:33:00:00:00:01) > Internet Protocol Version 6, Src: fe80::e4be:86ff:fe27:a33 (fe80::e4b= e:86ff:fe27:a33), Dst: ff02::1 (ff02::1) > Internet Control Message Protocol v6 > Type: Router Advertisement (134) > Code: 0 > Checksum: 0x6088 [correct] > Cur hop limit: 64 > Flags: 0x00 > Router lifetime (s): 300 > Reachable time (ms): 0 > Retrans timer (ms): 0 > ICMPv6 Option (Prefix information : 2001:78::1/64) > Type: Prefix information (3) > Length: 4 (32 bytes) > Prefix Length: 64 > Flag: 0xe0 > Valid Lifetime: 86400 > Preferred Lifetime: 14400 > Reserved > Prefix: 2001:78::1 (2001:78::1) Quoting RFC 4861 (http://tools.ietf.org/html/rfc4861#section-4.6.2 ): Prefix An IP address or a prefix of an IP address. The Prefix Length field contains the number of valid leading bits in the prefix. The bits in the prefi= x after the prefix length are reserved and MUST be initialized to zero by the sender and ignored by the receiver.=20 So that prefix should have been '2001:78::' Note that you don't necessarily need to include a prefix option in the RA. If you don't want clients on the link connected to the router to communicate directly on L2. This is the typical ISP use case. Bj=C3=B8rn