Robert, I remembered in JUNO release when i did flat network with my existing provider LAN then DHCP started giving IPs to my existing LAN clients and people started yelling their network is down :(
Following networking i configured. #neutron net-create network1 --provider:network_type flat --provider:physical_network extnet --router:external --shared #neutron subnet-create --name subnet1 --enable_dhcp=True --allocation-pool=start=10.0.3.160,end=10.0.3.166 --gateway=10.0.0.1 network1 10.0.0.0/21 After realizing issue i have changed --enable_dhcp=False On Fri, Aug 26, 2016 at 2:35 AM, Van Leeuwen, Robert <rovanleeu...@ebay.com> wrote: >> When i was trying to use DHCP in openstack i found openstack DHCP >> start provide ip address to my existing LAN machines ( we are using >> flat VLAN with neutron), that is why i disable openstack DHCP, Is it >> common or i am doing something wrong? > > I do not think this should happen. > It has been a while (Folsom) since I touched a setup with mixed “LAN” and > OpenStack DHCP but IIRC it works like this: > > AFAIK the leases file neutron uses is very specific and will only reply to > the mac-addresses that are in the dnsmasq config. > Looking at the dnsmasq process it is set to static: > From the man page: > The optional <mode> keyword may be static which tells dnsmasq to enable DHCP > for the network specified, but not to dynamically allocate IP addresses, only > hosts which have static addresses given via dhcp-host or from /etc/ethers > will be served. > > Usually the problem is the other way around: > The existing DHCP in the “lan” bites with what OpenStack does. (so an > OpenStack instance gets an IP from the lan DHCP) > This can be prevented by blacklisting the MAC address range your instances > get in your lan dhcp (Blacklist MAC starting with fa:16:3e ) > > Cheers, > Robert van Leeuwen > _______________________________________________ Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack Post to : openstack@lists.openstack.org Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
