Overlays Administration

To simplify deployment of overlay networking as much as possible, there is an esdc-overlay command that will automate for you most of the required operations. Moreover, it permanently stores the data in Danube Cloud’s configuration database so the compute node configuration can be easily re-applied at any time.

To apply all configuration to all/selected compute nodes, esdc-overlay runs an Ansible playbook that does all the hard work.


The esdc-overlay command should be run in the shell on the first compute node (the one that hosts the mgmt01 virtual server).

See also

You need to enable overlays prior to administering them. See How to enable overlays in Danube Cloud.

See also

To better understand to concepts of overlay networking in Danube Cloud have a look at the general overlay documentation.

What esdc-overlay can do:
  • Create/modify overlay rules.
  • Create/modify firewall configuration.
  • List configured overlay rules.
  • Create an adminoverlay, create appropriate vNICs, assign adminoverlay IP/MAC addresses.
  • Create and apply IPSec configuration.
  • Restart appropriate system services if needed.
  • Check overlay requirements.

Creating an overlay rule

Usage of the create subcommand:

esdc-overlay create <overlay_rule_name> [node_list|all] [raw_overlay_rule_string]

Creating an overlay rule on all compute nodes in the Danube Cloud installation can be as simple as running:

esdc-overlay create mynewoverlay

More complex usage can define subset of compute nodes that will host the new overlay rule:

esdc-overlay create localoverlay node01.local,node02.local,node03.local

Or you can create a completely custom overlay rule (all nodes, port 4790, MTU 1300):

esdc-overlay create customers all "-e vxlan -p vxlan/listen_ip=,vxlan/listen_port=4790 -s files -p files/config=/opt/custom/networking/customers_overlay.json -p mtu=1300"
  • If you provide a node list to esdc-overlay (anything other than all), only these compute nodes will be touched by Ansible.
  • In the node list, you can provide also non-existent node names. This way you can configure future nodes in advance.

Updating an overlay rule

Usage of the update subcommand:

esdc-overlay update [overlay_rule_name] [node_list|all] [raw_overlay_rule_string]

update has the same parameters as create. It can alter any overlay rule parameters and the change is immediately pushed to all or selected compute nodes.

The update subcommand can be also run without any parameters. In this mode it will (re)apply the configuration for all overlay rules on all compute nodes. It is very useful either to verify that the configuration is correct or to configure overlays on a newly added compute nodes.


After adding a new compute node, just run the esdc-overlay update command. It will fully configure overlay networking on the new compute node(s).

Modify a list of nodes that the specified overlay should be configured on:

esdc-overlay update localoverlay node03.local,node04.local,node04.local

Re-apply configuration for myrule overlay rule (Ansible will touch only nodes that the myrule should be on - it will retrieve the actual node list from the configuration database):

esdc-overlay update myrule

Delete an overlay rule

Usage of the delete subcommand:

esdc-overlay delete <overlay_rule_name>

The overlay rule will be first deleted on all compute nodes and then (if successful) removed from the configuration database.

List all configured overlay rules

Usage of the list subcommand:

esdc-overlay list
Sample output
[root@node01 ~] esdc-overlay list
adminoverlay 4791      all
customer1    4792      node02.local,node03.local,node06.local
customer12   4793      cust-node01.local,cust-node02.local
svc          4790      all

Create adminoverlay

Usage of the adminoverlay-init subcommand + example:

esdc-overlay adminoverlay-init <adminoverlay_subnet/netmask> [nodename1=ip1,nodename=ip2,...]
esdc-overlay adminoverlay-init node01.local=,node02.local=

This subcommand does the following operations:

  • Validate the specified IP subnet.
  • Create the adminoverlay overlay rule.
  • Generate/assign IP addresses for vNICs on all compute nodes.
  • Generate static MAC addresses for vNICs.
  • Set the vnc_listen_address if needed.
  • Write the configuration into /usbkey/config on all compute nodes.
  • Reload the network/virtual system service to apply new overlay configuration.
  • Add ipfilter rules to drop unencrypted VXLAN packets to/from internet.
  • Reload the network/ipfilter service.


  • adminoverlay_subnet/netmask - a network subnet with a netmask that will be used for the adminoverlay vNICs. The network is more or less equivalent to the admin network (but the admin network is still needed).
  • nodename1=ip1,... - if you want to set specific IP addresses for some/all compute nodes, you can do it here. Unspecified nodes will have an IP address assigned automatically. All IP addresses must be from the adminoverlay_subnet.

Modify adminoverlay

Usage of the adminoverlay-update subcommand:

esdc-overlay adminoverlay-update [nodename1=ip1,nodename=ip2,...]

This subcommand can modify assigned IP addresses. It will (as all commands except *-list) immediately run Ansible to apply the configuration.

Show adminoverlay info

Usage of the adminoverlay-info subcommand:

esdc-overlay adminoverlay-info
Sample output
[root@node01 ~] esdc-overlay adminoverlay-info
Adminoverlay subnet:
Adminoverlay netmask:
Adminoverlay vxlan_id: 2
Adminoverlay vlan_id: 2

IP           MAC                  NODE  00:e5:dc:dc:26:c3    node01.local  00:e5:dc:0f:c0:25    node02.local  00:e5:dc:0f:c0:42    node03.local

Enable firewall on all compute nodes

Usage of the globally-enable-firewall subcommand + example:

esdc-overlay globally-enable-firewall [allowed_IP_list]
esdc-overlay globally-enable-firewall admin_IP1,allowed_IP2,good_subnet/24
esdc-overlay globally-enable-firewall,,

By default, running esdc-overlay with create or update subcommands will create firewall rules that prevent sending unencrypted overlay packets over the external0 interface.

The globally-enable-firewall subcommand will further configure ipfilter on external0 interfaces of all compute nodes to whitelist mode. That means that it will permit connections only from allowed destinations. Note that network interfaces other that external0 will NOT be affected by this change. Virtual servers are also not affected by this operation. This is solely supposed to protect the hypervisors from internet threats.

Allowed destinations are:

  • all compute nodes
  • sources specified in allowed_IP_list

This subcommand can be used to update the allowed_IP_list after the firewall has been enabled.

The subcommand requires confirmation before applying changes on compute nodes. Running the subcommand without parameters can be used to review the actual firewall configuration.

Disable firewall on all compute nodes

Usage of the globally-disable-firewall subcommand:

esdc-overlay globally-disable-firewall

This subcommand will revert the effect of globally-enable-firewall on all compute nodes. All nodes are switched to blacklist ipfilter mode (allow all except explicitly forbidden).

The ipfilter itself is still active and you can add your own custom rules manually to any compute node by creating/editing a file in /opt/custom/etc/ipf.d/ directory and running /opt/custom/etc/rc-pre-network.d/010-ipf-restore.sh refresh.