From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: From: David Presotto To: 9fans@cse.psu.edu Subject: Re: [9fans] my cpu-in-vmware problem: it's weird :-) In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 23 Apr 2003 08:52:48 -0400 Topicbox-Message-UUID: 9694d364-eacb-11e9-9e20-41e7f4b1d025 Doing a ping before giving out an address is a suggestion from an RFC, don't remember which. It solves a world of problems; systems that have grabbed an unused address without using dhcp, dhcp servers that have lost their database, systems that overrun their lease (lots of these amongst dumb clients)... Our dhcpd does it too. If we don't have a static binding for a system AND the system has never gotten a dhcp address from us before we look for the oldest (we think unused) binding and then do a quick ping to make sure it really is unused. If noone answers the ping, we hand the address out. Vmware is being reasonable there. The random 06:34:12.096343 0:50:56:cc:31:ba Broadcast ip 590: 172.16.189.254.bootpc > 255.255.255.255.bootps: xid:0x7a2b9449 secs:8 C:172.16.189.254 file ""[|bootp] packet that you see might be 172.16.189.254 sending a dhcp request to refresh its dhcp lease. Are you giving our really short leases? I don't know the output of tcpdump that well. Having a client address (C:172.16.189.254) in a request is a sure sign of a renewal. However, there should also be DHCP options in the packet. Does tcpdump not print them?