Virtual Networking Scenario
The Service Network is a VLAN network that includes the following virtual network types:
- Private networks within the virtual datacenter
- External networks belonging to enterprises that allow access to networks outside the virtual datacenter
- Unmanaged networks belonging to enterprises that are assigned IP addresses outside the Abiquo environment
- Public networks using public IP addresses for virtual machines
Virtual machines on internal private networks can only communicate within the virtual datacenter. A virtual gateway can be used for communication outside the virtual datacenter. Virtual machines on public, external and unmanaged networks can communicate outside the virtual datacenter. VLAN tags should be assigned by the Network Administrator and entered into Abiquo for each external, public and unmanaged network.
How Abiquo Manages the Service Network
Abiquo can manage the service network with standard networking or software defined networking (SDN).
In standard networking, Abiquo management of the service network includes the following:
- VLANs: Virtual networks are separate VLANs to avoid network overlap and guarantee isolation.
- When a Virtual Machine is deployed, Abiquo generates a unique MAC address and binds it to an IP from the appropriate subnet and assigns it to the appropriate VLAN
- Network assignment can use the following options
- ISC DHCP Servers:
- Abiquo can remotely manage ISC DHCP Servers, so the DHCP server will always lease the right IP to the MAC address on a virtual machine.
- The Network Administrator configures the DHCP server or relay server so that it:
- Listens to VLANs
- Can be reached over a network from the virtual machines (on the service network) so they can obtain the IP leases
- Abiquo recommends the use of a DHCP relay server to provide VLAN support. See Configuring DHCP in the Administrator's Guide for information about how Abiquo uses DHCP
- Abiquo can inject the network connection into a VM using cloud-init, which requires templates that support cloud init
Abiquo also supports the VMware NSX and OpenStack Neutron systems for SDN.
Configuring the Service Network in the Switches
Do these steps for the following hardware to configure the service network.
- Top-of-Rack Switch
- Configure all ports in trunk mode
- Configure one port in access mode for each public VLAN ID for each hypervisor
- In Abiquo, create a public VLAN with each public VLAN tag
- For each external/unmanaged VLAN, you can configure one port in access mode with the corresponding VLAN IDs for each hypervisor
- In Abiquo, the Cloud Administrator can create external/unmanaged VLANs and/or reserve tags for future requirements
- Abiquo recommends that external/public/unmanaged networks use tags that are excluded from all racks' VLAN ranges
- Hypervisor Hosts
- Every hypervisor in the rack is connected to an 802.1Q trunk port in the top-of-rack switch. All virtual machines created in the hypervisors will have virtual NICs connected to virtual switches. One virtual switch should be created over each network interface on the hypervisor that is wired to a top-of-rack switch trunk port. Abiquo will create the necessary VLANs/VNICs in the virtual switches.
- DHCP Server
- The DHCP server (Abiquo Server) should also be connected to an 802.1Q trunk port in the top-of-rack switch. This is a requirement unless you are using cloud-init or only using unmanaged networks. See Configuring DHCP
- When you configure the DHCP Relay Server (or DHCP Server) that is providing VLAN support, for each VLAN you will need to supply one IP address on the service network but outside of the virtual datacenter range.
- Private, public and external networks require DHCP configuration
Private Network IP Ranges
For private networks isolated within a virtual datacenter, multiple VLANs can use the same IP address range, i.e. every customer can create its own network name (VLAN) with network address 192.168.0.0/24. This will create different VLANs but the same IP Network. Network administrators should be aware of this default configuration. For example:
Enterprise/Customer 1 -> VirtualDC 1
Network C1 -> 192.168.0.0/24, will be in VLAN5
Enterprise/Customer 2 -> VirtualDC 2
Network C2 -> 192.168.0.0/24, will be in VLAN8