1. Public Subnet: 209.229.131.0/24
Example Host Network Layout Management Subnet: 192.168.1.0/24
(Physical) Storage Subnet: 172.16.0.0/24
Default Guest Subnet: 10.0.1.0/24
Network Terminology
Public Subnet – Network directly on either the public internet or with public access. If CloudStack is in a completely
private environment (e.g. inside a corporate network) this is the outward facing address assigned to the virtual
router that all traffic is NAT’d through
Management Subnet – Somewhat self explanatory but this is the network that the management server lives on, as
well as your VM hosts and anything else for CloudStack to management.
Storage – As it relates to CloudStack, this is an optional network dedicated to secondary storage. If not specified, the
management network will be assumed for this role.
Guest Subnet – Unless a custom network is created, this subnet is used for the network and VLAN created for the
guest VMs within a domain, project, and/or account.
Link Local – A special type of virtual interface that exists only between the host and VM. This interface is created on
all system VMs as a way to interact with it securely. *NOTE: VMware does not support link-local interfaces so this
interface will not exist if you are running VMware.
Color Key Network Terminology
NOTICE: This documentation is for example/education purposes
Public
only. Your environment may differ either completely or in small
Management
ways from the examples provided here.
Storage
Guest
Link-local
*Note – Where a CIDR is specified it is because those virtual interfaces are created and managed by CloudStack so IP
address assignment is done at a guest (VM) level and therefore no configuration is required on the hypervisor
directly. It is noted for reference. Where an IP address is specified, that interface would be configured on the
hypervisor/host directly to provide that host with direct access to that network.
Basic Networking
Host with 2 Physical NICs
nic0 VLAN 100
management
IP ADDR 192.168.1.20
GATEWAY 192.168.1.1
VLAN 1
NETWORK storage
storage
IP ADDR 172.16.0.20
GATEWAY
NETWORK management
NETWORK public
public/guest
nic1 IP/CIDR* 209.229.131.0/24
GATEWAY 209.229.131.1
VLAN 500
*Basic Networking Note – In basic networking the “guest” and “public” networks are the same as guests are directly
assigned public addresses and guest segregation/security is achieved through the use of security groups. In
advanced networking mode guest segregation is achieved through the use of VLANs.
Advanced Networking
Host with 2 Physical NICs
nic0 NETWORK management
management
IP ADDR 192.168.1.20
GATEWAY 192.168.1.1
VLAN 1
NETWORK storage
storage
IP ADDR 172.16.0.20
GATEWAY
VLAN 100
NETWORK public
IP/CIDR* 209.229.131.0/24
public
GATEWAY 209.229.131.1
VLAN 500
NETWORK guest
IP/CIDR* 10.0.1.0/24
guest
nic1
GATEWAY 10.0.1.1
VLAN 600-799
Advanced Networking
Host with 4 Physical NICs
nic0 NETWORK management
management
IP ADDR 192.168.1.20
GATEWAY 192.168.1.1
VLAN 1
nic1 NETWORK public
IP/CIDR* 209.229.131.0/24
public
GATEWAY 209.229.131.1
VLAN 500
nic2
NETWORK guest
IP/CIDR* 10.0.1.0/24
guest
GATEWAY 10.0.1.1
VLAN 600-799
nic3
NETWORK storage
172.16.0.20
storage
IP ADDR
172.16.1.20
GATEWAY
VLAN 100
Note – In this example we are doing MPIO to the storage network. NIC bonding for performance and/or redundancy
would work as well but would include just a single IP address instead of 2. Another alternative would be to connect
nic2 to a dedicated guest network and nic3 to storage.