[Openstack-operators] Instances not getting DHCP Lease

Curtis serverascode at gmail.com
Thu Aug 31 21:38:38 UTC 2017

On Thu, Aug 31, 2017 at 11:55 AM, Divneet Singh
<divneetsingh.ml at gmail.com> wrote:
> I realize this is a common question , and I've looked through more than a
> couple of links , s, but I'm afraid I'm new enough to OpenStack that I
> wasn't able to make sense of many of the replies and was unable to solve my
> problem after searching.
> I have a multi-node deployment with one controller/network node and one
> compute node. When I create a cirros image on the Compute node, I see in the
> Horizon interface that a DHCP address is assigned, but when I run ifconfig
> in the VNC console on the Horizon dashboard, I see the instance has no IP
> address
> Can anyone suggest possible fixes? As I said, I'm pretty new to OpenStack.
> I'm sure that I haven't provided all of the information needed to solve this
> problem; if someone could tell me what further information would be useful.

What I usually do, and this might not be easiest/best, is, given you
do have console access, to manually set the IP in the cirrus node.

Then I enter the ip name space for the dhcp server on the network node
(sudo ip netns exec qdhcp-<thenetwork> bash), and see if I can ping
the cirrus node and vice-versa, things like that. Making sure to add a
security group rule to at least allow ICMP. See if you can at least
get an arp entry for the virtual machine's IP.

Usually if there is no connectivity at all it's b/c a vlan is missing
for the physical interface on the switch (not sure how your deployment
is setup), or the also neutron configuration settings are incorrect in
terms of bridge mappings and such, usually something simple like that.

Another option is to reboot or retry dhcp on the cirrus vm and tcpdump
on the physical interface the dhcp server is on and watch for dhcp
traffic, and you could do that on the compute node as well, looking
for both request and response, again to validate basic connectivity.

If you still are having issues, let us know how you deployed openstack
(distro?) and what kind of network you are using (vxlan, vlan?),
whether it's linux bridge or ovs, things like that.


> Thanks !
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> OpenStack-operators at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators

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