- Now let's take a look at a few VPC peering scenarios.
There are many, many ways that you could
segregate your networks,
separate applications and departments,
and peer VPCs using different strategies.
One strategy might be
that you want to isolate different services.
In this example, we might want
our web application in one network,
all of our back end servers in yet another network,
and then our databases in their own network.
This is totally up to you.
It's fairly arbitrary; there's nothing within
Amazon Web Services that says you have to segregate
and separate your networks in any particular way.
It's all up to you; whatever makes the most sense
for your application and for your business.
Some business choose to segregate
their networks by department: whereas finance department
has their resources and their VPC,
and accounting has their resources in their own VPC.
But they're connected and they can talk to each other.
Accounting needs access to resources
that are in the finance department,
so they would peer those two VPCs.
In another situation, maybe you need centralized resources
where you have various departments.
They are all essentially isolated from each other.
We don't want these departments, really,
gaining access to each other's resources,
but they all need access to the corporate internet,
or the corporate file sharing server.
Here's that example of you have
those kinds of shared resources in one VPC,
and you keep your departmental,
specific departmental resources in their own VPCs.
Another approach to VPC peering might be
that you put shared resources in a VPC,
and you have different customers that have access to that.
Each customer, or each vendor having their own VPC
and their own account, and then you're granting them access
to your pool of shared resources.
So again, it's all arbitrary.
Amazon does not dictate
how we do this,
other than that, as we've talked about,
VPCs, VPC peering is a one-to-one relationship
with no overlapping IP ranges.
Other than that, you can pretty much do what you want.
Whatever makes sense for your application and your business.