Adam, it sounds like a networking issue, check that all hosts can talk to each 
other on the same vlan that is used for guest network. I had the same issue 
with advanced networking when my vlans were not properly setup on the switches. 

Andrei 

----- Original Message -----

From: "Adam" <adam.scarce...@gmail.com> 
To: users@cloudstack.apache.org 
Sent: Saturday, 16 November, 2013 7:08:50 PM 
Subject: Guest VMs not able to acquire DHCP IP from Virtual Router unless Guest 
and VR are on the same KVM host 

Hi All, 

I have a new and very strange issue that for the life of me I cannot seem 
to track down and fix. 

I have CS 4.2 running on 5 hosts in a simple basic zone. All is working 
fine, except that my Guest VMs cannot seem to get a DHCP lease from the 
Virtual Router unless I migrate the Guest VM to the same physical KVM 
Host running the VR. That would seem to indicate a firewall issue, but I've 
tested by turning off both the firewalls (VR KVM Host iptables & Guest VM 
KVM Host iptables). It didn't help. The only way to fix it is to migrate 
the Guest VM to the same KVM Host that's running the Virtual Router. 

NOTE: The Console Proxy has worked flawlessly this whole time. 

So, if a Guest VM starts on a different physical KVM Host, it will not get 
an internal IP of 169.254.x.x. All along the Console Proxy works fine. Then 
if I migrate the Guest VM to the same KVM host that's running the VR, DHCP 
automatically starts working and the Guest VM receives a proper IP address 
of 10.97.38.x. Then I can migrate the Guest VM back to any other physical 
KVM Host and believe it or not, it continues to work flawlessly, until I 
either reboot the VM or restart the network services. Then it cannot see 
the VR again and instead receives an internal IP of 169.254.x.x. If I set a 
static IP address & DNS everything works fine, no matter where the Guest VM 
is running. 

Setting static IPs is not an option 
Running all the Guest VMs on the same physical KVM host is not an option 

I desperately need to track down the root cause of this issue so I can 
release this cloud to my entire department by Monday morning. Someone 
please help! 

Best Regards, 



Adam Scarcella 

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