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6.3 Setting Up And Creating A Custom VPC
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6.3.4 Subnets With Static IP Addresses In A Custom VPC Recommendation
Subnets can be set up in many ways inside a custom VPC. The following is recommended:
• There must be exactly one network containing all the instances which have static IP addresses.
This network should contain the cloud director. The network with the cloud director is arbitrarily
referred to as the “public” network.
• There must be zero or more networks containing instances with no static IP addresses assigned to
them. Such networks are arbitrarily referred to as the “private” subnets.
Instances in the private subnets have no static IP addresses assigned to them, so by default they do
not communicate with outside networks. To allow them to connect to the outside, the cloud director
instance is automatically configured by CMDaemon as a NAT gateway for outside-bound traffic, for the
instances existing inside the private subnets.
6.3.5 Assignment Of Nodes To Subnets And Cloud Platforms
A cloud node instance is connected to a network by its eth0 interface. The network is one of those
covered in following table, that is: classic physical, classic emulated, or subnet of a custom VPC.
what cloud is the eth0
cloud instance type and network
interface connected to?
that the node joins
classic cloud
classic cloud cluster instance, in classic physical network (10.0.0.0/8)
defaultVPC
defaultVPC instance, in classic emulated network (172.31.0.0/8)
custom VPC
inside VPC instance, in the connected subnet (if any) of that network
Therefore, when the cloud node is being created inside EC2, the CMDaemon must tell the EC2 environment which of these networks is going to be attached to the eth0 interface of the newly created cloud
node.
This information is deduced by CMDaemon by looking at the interface configuration of the cloud
node Bright Cluster Manager. More specifically, it is deduced from the value set for network in the
cloud node’s eth0 interface settings.
If that network is part of a custom VPC, that is, if it is a subnet, then the node starts inside the custom
VPC instance. Otherwise, it starts inside the EC2-Classic or defaultVPC instance in that region.
For example, the cloud director node is started inside the vpc-0-sn-0 network in the following
session. It is considered a custom VPC node, and starts up inside the EC2-VPC platform:
Example
[bright71->device[us-west-1-director]->interfaces]% list
Type
Network device name IP
Network
------------ -------------------- ---------------- ---------physical
eth0 [dhcp]
0.0.0.0
vpc-0-sn-0
tunnel
tun0 [prov]
172.18.255.251
us-west-1
In contrast, if the cloud network assigned to the eth0 interface is the cloud network representing
the network environment of an EC2-Classic or defaultVPC cloud, then the node is considered to be an
EC2-Classic node. It then starts up inside the EC2-Classic platform by default:
Example
[bright71->device[us-west-1-director]->interfaces]% list
Type
Network device name IP
Network
© Bright Computing, Inc.