From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Wireless router with 2 MACs: okay with mswin, not with Linux ? Date: Mon, 25 Sep 2006 17:14:38 -0400 Message-ID: <451846BE.5030704@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from proof.pobox.com ([207.106.133.28]:14296 "EHLO proof.pobox.com") by vger.kernel.org with ESMTP id S1751347AbWIYVOm (ORCPT ); Mon, 25 Sep 2006 17:14:42 -0400 To: netdev@vger.kernel.org, davem@davemloft.net, linux-kernel@vger.kernel.org Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi all, I'm posting this from a hotel which has a wireless AP (B+G) for guests. It took me several hours to figure out how to get the connection working with my 2.6.18 notebook -- works just fine with other guests' mswin machines. WEP is used, and is set up and working just fine: I can access the AP's built-in web interface without any troubles. But.. The AP has two MAC addresses: # arping -c1 192.168.1.1 -I eth1 ARPING 192.168.1.1 from 192.168.1.53 eth1 Unicast reply from 192.168.1.1 [00:11:F5:BA:67:AA] 2.164ms Unicast reply from 192.168.1.1 [00:11:F5:77:38:C2] 5.696ms Sent 1 probes (1 broadcast(s)) Received 2 response(s) # The first MAC can connect locally to the AP, but not outside. The second MAC can connect locally and/or outside. Linux only seems to ever use the first (no good) MAC for the AP, rather than the second. Whenever I try an outside access, the AP sends a gratuitous ARP reply, telling my machine to use the other MAC. This seems to be ignored by Linux, but heeded by Windows. For now, I've just written a small script to detect such a situation, and to set a static ARP mapping for the second MAC. This works, but is way beyond "normal usage" for most people. Surely there's a flag or something to have the kernel cope with this? ???? -- Mark Lord Real-Time Remedies Inc. mlord@pobox.com