Dhcp3 configuration for XEN server

globemast · 10-19-2009, 02:02 AM

Hi all,

I am running an Ubuntu 9.04 Server (32-bit) and i have installed the XEN kernel in order to run a XEN Virtual Appliance (VA).

I want to setup a DHCP server in order to serve the VAs. The host machine is part of a server farm and uses a static IP address.

So far i have created a virtual interface (eth0:1) so as not to mess with the hardware (eth0) interface and cause any problems in the cluster.

However I'm struggling in getting the DHCP server running. I'm attaching below the dhcpd.conf , dhcp3-server files and syslog.

Any help would be highly appreciated...

Thanks.

Code:

#
# DHCP Server Configuration file.
#   see /usr/share/doc/dhcp*/dhcpd.conf.sample  
#

# Required for dhcp 3.0+ / Red Hat 8.0+
ddns-update-style interim;                                   
ignore client-updates;

default-lease-time 259200;
max-lease-time 518400;

subnet 192.168.1.0 netmask 255.255.255.0 {
	option subnet-mask 255.255.255.0;
	option broadcast-address 192.168.1.255;
	option routers	192.168.1.1;
	option domain-name "rubisva.cy";
	range 192.168.1.50 192.168.1.100;
	option domain-name-servers 194.42.16.11;
	#option domain-name-servers 192.168.1.1;
}

Code:

#
# DHCP Server Configuration file.
#   see /usr/share/doc/dhcp*/dhcpd.conf.sample  
#

# Required for dhcp 3.0+ / Red Hat 8.0+
ddns-update-style interim;                                   
ignore client-updates;

default-lease-time 259200;
max-lease-time 518400;

subnet 192.168.1.0 netmask 255.255.255.0 {
	option subnet-mask 255.255.255.0;
	option broadcast-address 192.168.1.255;
	option routers	192.168.1.1;
	option domain-name "rubisva.cy";
	range 192.168.1.50 192.168.1.100;
	option domain-name-servers 194.42.16.11;
	#option domain-name-servers 192.168.1.1;
}

Code:

Oct 16 16:50:56 vm101 dhcpd: No subnet declaration for eth0:1 (0.0.0.0).
Oct 16 16:50:56 vm101 dhcpd: ** Ignoring requests on eth0:1.  If this is not what
Oct 16 16:50:56 vm101 dhcpd:    you want, please write a subnet declaration
Oct 16 16:50:56 vm101 dhcpd:    in your dhcpd.conf file for the network segment
Oct 16 16:50:56 vm101 dhcpd:    to which interface eth0:1 is attached. **

P.S I have already posted this question on the Ubuntu forums with little feedback. Here is the link to the post:
http://ubuntuforums.org/showthread.php?t=1292804

globemast · 10-20-2009, 02:58 AM

Hi,

Any suggestions?

johnewing · 10-20-2009, 08:25 AM

What network settings have you given eth0:1 ?
output of ifconfig would be useful.

globemast · 10-21-2009, 02:46 AM

eth0:1 Link encap:Ethernet HWaddr 00:30:48:27:44:4e
inet addr:192.168.1.123 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

johnewing · 10-21-2009, 05:55 AM

Is eth0 on a different subnet ?
ie
eth0 192.168.4.1
eth0:1 192.168.1.123

If it is you might need to use the shared-network directive

from the man pages.

Code:

  The shared-network statement is used to inform  the  DHCP  server  that
       some  IP subnets actually share the same physical network.  Any subnets
       in a shared network should be declared within a  shared-network  state-
       ment.   Parameters  specified  in  the shared-network statement will be
       used when booting clients on those subnets unless  parameters  provided
       at  the  subnet or host level override them.  If any subnet in a shared
       network has addresses available for dynamic allocation, those addresses
       are  collected  into a common pool for that shared network and assigned
       to clients as needed.  There is no way to distinguish on  which  subnet
       of a shared network a client should boot.

But thats only a guess, not a DHCP expert unfortunately.

johnewing · 10-21-2009, 06:02 AM

Just found this

According to Redhat you can't have a DHCP server on an alias interface.

http://www.redhat.com/docs/en-US/Red...CP_Server.html

globemast · 10-22-2009, 01:57 AM

Hi,

Yes eth0:1 is on a different subnet than eth0.

But your last post confused things even more.