From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mugunthan V N Subject: DHCP response received after 500mS not handled while having multiple Ethernet interfaces Date: Wed, 28 Nov 2012 01:28:40 +0530 Message-ID: <50B51B70.5050804@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: "davem@davemloft.net" To: "netdev@vger.kernel.org" Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:53299 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752039Ab2K0T7I (ORCPT ); Tue, 27 Nov 2012 14:59:08 -0500 Sender: netdev-owner@vger.kernel.org List-ID: Hi While testing AM335X which has Dual EMAC feature, I came across an issue. Setup: Board: AM335X-EVMSK with Dual EMAC implementation with eth0 connected and eth1 not connected to switch. Router: Trendnet Wireless router TEW-652BRP Issue: While booting with multiple Ethernet interface, kernel logs as "DHCP/BOOTP: Ignoring delayed packet" and ignores the DHCP response packet. Analysis: The router is giving a DHCP response only after 500mS which I confirmed by capturing Ethernet packets While looking at net/ipv4/ipconfig.c, it seems that waiting period of DHCP response with multiple interface is 500mS, if we get a response from the server after 500mS, it is ignored as ic_dev_xid will hold the next interface xid which is updated while sending DHCP request after timeout on the next interface. Is this 500mS waiting for response period is per protocol? In my view even if we get a response after 500mS and DHCP request has moved to next interface we need to handle the response. Can someone comment on this approach is right or is there some other way to handle the issue. Regards Mugunthan V N