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[[DynamicDNSGuide]] *Setting up Dynamic DNS [#qfbe80f0] The Eucalyptus cloud front end has a Domain Name System (DNS) service built into it that will respond to DNS requests in order to support virtual hosting of buckets (mapping bucket names to IP addresses) and instance DNS (mapping of hostnames to instance public and private IP addresses). **Enabling DNS in Eucalyptus [#ccf93330] Since most Linux distributions have "dnsmasq" or "bind" or another DNS server running on the same physical host as the CLC, DNS in Eucalyptus is disabled by default. The Eucalyptus administrator can enable DNS after disabling or re-configuring any other services that listen on port 53. To do so, edit $EUCALYPTUS/etc/eucalyptus/eucalyptus.conf on the CLC machine and change the value of "DISABLE_DNS" to, DISABLE_DNS=N then, restart "eucalyptus-cloud". Note: To verify that the DNS service is running, try running "netstat -al" and look for 53. Port 53 should be bound by the process "eucalyptus-cloud" **Configuring DNS in Eucalyptus [#z1213f3e] First, login to the front end admin web interface (https://<front end IP>:8443) and click on the "Configuration" tab. Next, pick a subdomain within your domain that the Eucalyptus DNS system will service. Set the nameserver IP to the IP of the cloud front end that is accessible by your master DNS system. Then, set the domain that the Eucalyptus front end will service to <subdomain>.<domain> Finally, you will need to change your master DNS configuration to point to the CLC public IP (entered in the above step) as the nameserver for your chosen subdomain within your organization. Optionally, you can change your client's config (/etc/resolv.conf on Linux) to point to the cloud front end IP directly, but note that you will have to do this on each system that needs to access the Eucalyptus DNS service. **Using DNS [#s8a8bdc6] After DNS is setup correctly, creation and deletion of buckets will automatically create DNS entries. The DNS service embedded in the CLC will respond with the Walrus IP when a DNS request is made for <bucketname>.walrus.<subdomain>. In addition, instances IPs will be mapped as euca-A.B.C.D.eucalyptus.<subdomain>, where A.B.C.D is the IP address (or addresses) assigned to your instance.
