From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3F33BC10.8060407@imc-berlin.de> Date: Fri, 08 Aug 2003 17:04:48 +0200 From: Steven Scholz MIME-Version: 1.0 To: LinuxPPC Subject: Questions about ARP Content-Type: text/plain; charset=windows-1252; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Hi there, Microsoft uses "Automatic Private IP Addressing" to grab an IP address if a DHCP request fails. In the section "Resolving IP Conflicts" in http://www.winnetmag.com/Articles/Index.cfm?ArticleID=7464 it says How does the client know the IP address it's using isn't in use by another machine? It uses a gratuitous Address Resolution Protocol (ARP) to resolve potential conflicts. Let’s say the first client that boots up wants to assign itself an IP address of 169.254.10.20. It sends out a gratuitous ARP, but no one answers, so it keeps the address ... Next, a third client boots up and picks 169.254.10.20, the same address the first client chose. The first client tells the third client that it's already using that IP address, so the third client tries a different IP address and keeps it if there's no conflict. I can see this behaviour if I connect an embedded DOS TCP/IP device to a Windows XP computer (using a cross-linked twisted pair) and force the IP of the DOS device to be the same as the one that the Windows XP computer is going to claim. Fair enough. But when I connect my MPC8xx board with Linux it seems that Linux is not responding to the ARP requests done by the Windows machine. Result: Both machine end up with the same IP address. Did I miss something? I did not find an kernel option saying something about ARP... Any ideas? Could someone maybe try this as well? Please? Thanks a million, Steven ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/