So having seen this specific problem scores of times, it's almost always network config related. Several potential problems to look out for:
1. Another DHCP server on the same network. (There are ways of mitigating this, but for the time being, lets just say that CloudStack's VR should be the only DHCP server on the network. 2. Shell into the physical machine that the VR is running on. Using tcpdump (with filters of course) Do you see the broadcast asking for a DHCP address coming from the VM on the other physical machine? Do you see the VR answering the request? If so, move to step 3. If not (for either of those questions) - you aren't communicating between the two physical hosts - your switch config is suspect. 3. Shell into the physical machine that the VM is running on - You've seen the response with an IP address assigned go out - so see if it is seen by the physical host NIC? If not, you've again. If you see the response (and are sure it's from the VR and not another DHCP server) come back and tell us - something funky is going on. --David On Sun, Nov 17, 2013 at 10:11 AM, Adam <[email protected]> wrote: > Yes, I've disabled the firewall on both KVM hosts in question and still no > dice. I can't even ping the VR from my guest VM, but when I set the eth0 > device on the guest to static everything works fine, which makes no sense > at all to me. Simply setting the NIC to static allows me see the VR. > Switching back to DHCP kills it again. I do not understand what is required > for the guests to acquire a DHCP lease from the VR. I know that the VR is > running dnsmasq, and I've tailed the /var/log/dnsmasq.log for more info, > but only see a DHCP request when the guest is on the same KVM host as the > VR. > > Does anyone know exactly how to troubleshoot this scenario? I'm not even > sure what to look for. > > -Adam > > Best Regards, > > > > Adam Scarcella > > > On Sat, Nov 16, 2013 at 5:43 PM, Carlos Reátegui <[email protected]>wrote: > >> Did you also check the host firewall? Try disabling. >> >> > On Nov 16, 2013, at 1:51 PM, Adam <[email protected]> wrote: >> > >> > The hosts have static IPs (10.97.38.[10-14]) and can all see and talk to >> > each other via IP and hostname. I'm only using a basic zone so no VLAN >> > tagging or anything funky like that. >> > >> > Best Regards, >> > >> > >> > >> > Adam Scarcella >> > >> > >> > On Sat, Nov 16, 2013 at 4:17 PM, Andrei Mikhailovsky <[email protected] >> >wrote: >> > >> >> >> >> >> >> 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" <[email protected]> >> >> To: [email protected] >> >> 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 >> >> >> >> >>
