Skip to main content

Static IP Strategies

By default, a Gallium hypervisor obtains its management address automatically. It requests DHCP on each physical interface and uses whichever connection answers to reach the Gallium Console. This works well on most networks, but it creates a problem in one common scenario: when the DHCP and DNS services the hypervisor depends on are themselves running as guest virtual machines on that same hypervisor.

Problem​

When a hypervisor hosts the DHCP and DNS services for its own network, a circular dependency emerges:

  • The hypervisor needs DHCP and DNS to obtain an address and stay reachable from the Console.
  • Those services run on guest virtual machines that only exist while the hypervisor is running.

If the hypervisor reboots before its guests are up, there is nothing on the network to hand it an address, and it cannot come back online to start the very VMs that would provide one. The two strategies below break this cycle by giving the hypervisor an address that does not depend on its own guests.

Option 1: Management VLAN​

The recommended approach is to isolate hypervisor management traffic onto a dedicated VLAN whose addressing is provided by your router or firewall rather than by a guest VM. Because Gallium's per-host networking passes the native (untagged) VLAN of a physical port straight through to the hypervisor, you can reserve that native VLAN for management and carry guest traffic on tagged VLANs layered on top.

  1. Create a dedicated management VLAN on your router or firewall for hypervisor traffic.
  2. Configure the physical switch port connected to the hypervisor so that this management VLAN is passed as the native (untagged) VLAN, while guest VLANs are passed tagged on the same port.
  3. On the router or firewall, set up a small DHCP scope on the management VLAN containing a single reserved address for the hypervisor. Because this DHCP service lives on your network hardware rather than on a guest VM, it is available the moment the hypervisor powers on.
  4. Place your guest virtual machines on tagged VLAN networks. In the Console, these are VLAN networks created as children of the hypervisor's bridge. See Managing Networks.

This keeps the hypervisor reachable independently of any guest, while your VMs continue to receive DHCP and DNS from the services they host. For background on bridges and VLAN child networks, see the Networking Overview.

Option 2: Static IP​

If you cannot dedicate a management VLAN, the hypervisor can instead be given a fixed address that never changes. To request a static configuration, raise a support ticket through the Gallium Console and supply the following details:

  • IP address: the fixed address to assign to the hypervisor.
  • Subnet mask: the mask for the management subnet.
  • Gateway: the default gateway the hypervisor should route through.