On Wednesday, 10/13/2004 at 05:30 ZE2, Max <[EMAIL PROTECTED]> wrote: > Guys... > I've a big problem... > I'm not able to run a DHCP server on zLinux. > In the /var/log/messages data between server and > client seems to be exchanged but nothings appens in my > client! > > The configuration file of the DHCP server is the same > that is running fine on a RedHat installed on xSeries. > > No way to understand!!!!
If your DHCP client is connected to the network via an OSA card, it may share a single MAC address with dozens of other hosts using that same OSA card. A typical ethernet dhcp registration begins something like this: (1) Client sends (broadcast) a DHCPDISCOVER frame to ask for an IP address (2) Server hears DHCPDISCOVER and sends (unicast) a DHCPOFFER frame with an IP address (3) Client hears DHCPOFFER and accepts the new IP address The server can send a unicast DHCPOFFER because it gets the client's MAC address from the DHCPDISCOVER frame. If the client is using a real (hardware) OSA interface, the MAC address identifies the OSA, but not the client interface. If a host on this OSA card is registered as the "primary router" the DHCPOFFER will probably be delivered to that interface. Otherwise, it will be discarded. In a shared port environment, the DHCP client should use the broadcast flag in the DHCPDISCOVER frame (usually option "-b" on the client command). This asks the DHCP server to respond with a broadcast (instead of a unicast) DHCPOFFER. The broadcast frame is delivered to every host in your broadcast domain, so you can count on it reaching the DHCP client. The bad news is that some dhcp implementations DO NOT support the broadcast flag. If your current dhcp package does not support the "-b" option you may need to try a different package (or ask the developers to add broadcast support for the DHCPOFFER). Regards, Dennis ---------------------------------------------------------------- Dennis Musselwhite ([EMAIL PROTECTED]) +1(607)429-3831 z/VM Development -- CP Network Simulation -- IBM Endicott NY ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
