From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([69.77.167.62] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1KvCtd-0002pX-Tf for garchives@archives.gentoo.org; Wed, 29 Oct 2008 15:23:46 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id DE1F4E0558; Wed, 29 Oct 2008 15:23:43 +0000 (UTC) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.187]) by pigeon.gentoo.org (Postfix) with ESMTP id 7CE89E05E4 for ; Wed, 29 Oct 2008 15:23:43 +0000 (UTC) Received: by nf-out-0910.google.com with SMTP id c7so29432nfi.26 for ; Wed, 29 Oct 2008 08:23:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:from:reply-to:to:subject:date :user-agent:references:in-reply-to:mime-version:message-id :content-type:content-transfer-encoding; bh=iJvxsyLgyDPtyfEeM3aGRcsCQwmAtM0/d62ZLJyI92U=; b=UkQ02d9nw1YB2Y9BV2JlP9A2TfVOU2E1nzPG8Reo1iw698ku5PJ9UaxPpQKlWQ9Vmy BUfBs208EaRL/v4jZxoknxNSy/sIG9z/eEQ2sewP1ka8M2djHg3DgsMTT7oZcZiBiE0X 6zChXF1b6Vh0j79Lpvu+gi95Da2qreWykEALI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:reply-to:to:subject:date:user-agent:references:in-reply-to :mime-version:message-id:content-type:content-transfer-encoding; b=l/GJzZQ1nmvyvTcjGt7iolpnF22Wpj0smV3t4pFMx4NO1JkN6dih+nPqzW2Atv43zG RPUjViWRxlsVJCQRQ3V9rlYYoepJ0sv0EcY/AjMMSBnnhECIMdiBeRr05lj23e9e7nne +UXAM7Nnyh1iTKwPNMTqnuZ/DlnUQ+Ov09HxA= Received: by 10.210.58.13 with SMTP id g13mr10133882eba.183.1225293821600; Wed, 29 Oct 2008 08:23:41 -0700 (PDT) Received: from ?192.168.2.4? (athedsl-415442.home.otenet.gr [79.131.174.208]) by mx.google.com with ESMTPS id 7sm23185eyg.0.2008.10.29.08.23.38 (version=TLSv1/SSLv3 cipher=RC4-MD5); Wed, 29 Oct 2008 08:23:39 -0700 (PDT) From: Mick To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Re: dhcpd uses fake MAC address Date: Wed, 29 Oct 2008 10:49:36 +0000 User-Agent: KMail/1.9.9 References: <200810260232.42584.volker.armin.hemmann@tu-clausthal.de> In-Reply-To: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Message-Id: <200810291049.39124.michaelkintzios@gmail.com> Content-Type: multipart/signed; boundary="nextPart26076233.QRYUkY9HVO"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit X-Archives-Salt: 9ca0f34e-6357-4cc1-860d-2b6420ca4d7e X-Archives-Hash: 2a76719efe1c7cf30899a785a1f37d7a --nextPart26076233.QRYUkY9HVO Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Sunday 26 October 2008, Nikos Chantziaras wrote: > Volker Armin Hemmann wrote: > > I don't need it. But in our network most people use windows - and don't > > know anything about computers. So they get their static ip assigned by > > dhcp. Once in a while the server chokes - and that is one of the many > > reasons why I usually don't use dhcp. There are a lot better ones, but > > if you really need to know the details, ask off-list ;) > > Anyway, maybe it's not a dhcp problem but originates further down the > stack. Not sure what I'm looking for though :P I've posted a couple of weeks ago about the same thing=20 titled "net-misc/dhcpcd-4.0.1-r1 change of USE flags". I have since found= =20 that the problem you observed essentially boils down to the router's dhcp=20 server implementation and the way it treats the client_identifier string. The dhcpcd package complies with RFC2131 and generates and broadcasts a=20 unique device identification number for your NIC (DUID). DUID is the long= =20 number you have posted, the tail end of which contains the MAC. The server= =20 is meant to use this number (according to RFC4361, clause 6.3): =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D DHCPv4 servers that conform to this specification MUST use the 'client identifier' option to identify the client if the client sends it. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D All this is fine and dandy, if only the dhcp server in question could direc= tly=20 correlate the dhcpcd generated DUID to your MAC. Unfortunately, many route= rs=20 won't. They will treat the static MAC settings as a different device than= =20 that of the DUID and issue your PC with a different than the preselected=20 static IP address. You can run dhcpcd eth0 -T -d to verify what's happenin= g=20 in your case, although a newly issued IP address which is different than th= e=20 preset static IP address is a giveaway. More sophisticated routers allow you to set up on their CLI static LAN IP=20 addresses using the DUID string, instead of the client's MAC hardware=20 address. Previous versions of dhcpcd had the vram USE flag which copied the hardware= =20 address into the DUID string and the dhcp servers would happily recognise t= he=20 original network device, while using the DUID string. Now the vram flag is= =20 gone. Therefore, if you cannot set up static IP addresses with your router= 's=20 CLI using the client_indentifier string (like e.g. on Cisco and=20 Adtran/Netvanta routers), the only other solution would be to set it on the= =20 client side. That's an inconvenient solution if you have a laptop which=20 connects to all sort of networks with different LAN IP addresses/ranges. I= n=20 that case you may have to run ifconfig and route manually each time you=20 connect to a network. =2D-=20 Regards, Mick --nextPart26076233.QRYUkY9HVO Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEABECAAYFAkkIP8MACgkQ5Fp0QerLYPdOCwCgl3LWMTb43HUIfvqTVksv1oH4 ghYAoJaVgndxslgd9iFpX0JogxROWWi8 =8TI0 -----END PGP SIGNATURE----- --nextPart26076233.QRYUkY9HVO--