The Dynamic DNS service provides a unified, federation-wide Dynamic DNS support
for VMs in EGI infrastructure. Users can register their chosen meaningful and
memorable DNS host names in given domains (e.g.
assign to public IPs of their servers.
By using Dynamic DNS, users can host services in EGI Cloud with their meaningful service names, can freely move VMs from sites to sites without modifying server/client configurations (federated approach), can request valid server certificates in advance (critical for security) and many other advantages.
The Dynamic DNS offers a web GUI portal where users can login using their Check-in credentials. For doing so, click on the Login link (top left) and then click on the egi button.
Once logged in, you will be presented with the following page:
To register a new DNS host name:
click on Overview and then on Add Host.
Type in the host name you’d like to register and select the domain to use.
The portal will then show you a secret than can be used for updating the host ip whenever needed. Note it down so you can use it later.
From the VM you’d like to assign the name to, run a command like follows:
<hostname> is the full hostname generated before, e.g.
<secret> is the secret generated
in the previous step. You can add that as a boot command in your
#cloud-config runcmd: - [ curl, "https://<hostname>:<secret>@nsupdate.fedcloud.eu/nic/update" ]
You can also manually edit your registered hostnames in the Overview menu by clicking on the hostname you’d like to manage
Hostnames/IP addresses are not expired so no need to refresh IP addresses if
no changes, it is enough to run once. You can add the following command
curl https://HOSTNAME:SECRET@nsupdate.fedcloud.eu/nic/update to cloud-init
as described above to assign hostname automatically at VM start
DNS server set Time-to-Live (max time for caching DNS records) to 1 min for
dynamic DNS, but MS Windows seems to not respect that. You can clear DNS cache
in Windows with
ipconfig /flushdns command with Administrator account
GET /nic/update?hostname=yourhostname&myip=ipaddress Host: nsupdate.fedcloud.eu Authorization: Basic base64-encoded-auth-string User-Agent:
base64-encoded-auth-string: base64 encoding of username:password
username: your host name
password: your host secret
hostnamein the parameter string can be omitted or must be the same as
myipin the parameter string if omitted, the IP address of the client performing the GET request will be used
For updating IP address, only hostname and its secret are needed. No user information is stored on VM in any form for updating IP.
NS-update server uses HTTPS protocol, hostname/secret are encrypted as data and not visible during transfer so it is secure to use the update URL
NS-update portal does not store host secret in recoverable form. If you forget the secret of your hostname, simply generate new one via “Show configuration” button in the host edit page. The old secret will be invalid.