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AW:DNS in virtual router not stable

Hi Ivan,

I've seen this problem to. The solution is to handle your ip address by the host youre adding static by api or gui. The router VM uses the old host entries set in /etc/hosts if you cleanup vpc network. The host file will be cleared.

Kind Regards


Von meinem Huawei-Mobiltelefon gesendet

-------- Originalnachricht --------
Betreff: DNS in virtual router not stable
Von: Ivan X Yue <ivanyue@xxxxxxxxxx>
An: users@xxxxxxxxxxxxxxxxxxxxx

Hi, all, 

We are using Cloudstack 4.9.2 with KVM and advance networking

We are having VPC network, and need to continuously adding / removing VM. 
One issue we found is, from time-to-time, on the VM deployed, it gets 
error that the hostname of the other VM is not resolved.  We dig into the 
VR, and it seems that every time a VM is added or removed, the dnsmasq 
needs to be restarted.  And based on /var/log/dnsmasq.log, there is 2 
second delay before dnsmasq is running again.  Quite likely while restart 
is happening, the DNS is not working and therefore VM will not be able to 
resolve hostname. 

Dec 12 15:22:55 dnsmasq[6479]: exiting on receipt of SIGTERM
Dec 12 15:22:57 dnsmasq[6747]: started, version 2.62 cachesize 150
Dec 12 15:26:36 dnsmasq[6747]: exiting on receipt of SIGTERM
Dec 12 15:26:38 dnsmasq[28921]: started, version 2.62 cachesize 150

We don't see this issue in CloudStack 4.11.  In 4.11, we also see dnsmasq 
being restarted in dnsmasq.log, but there is no delay between exiting and 

Is there anything we can do in 4.9.2 to have the DNS more stable.  e.g. 
can dnsmasq not being restarted even new VM info is added?  Or can it just 
reload the VM info?