Module 7: Create a networking env Flashcards
Reminder on AWS Physical infrastructure
Servers in racks in data center. Every rack has network routers and switch to route traffic.
Data centers grouped in AZ.
AZ grouped in regions and connected with 0.001-9 second latency network.
Region inter connected with 0.01-9 second latency
Reminder on Virtual networks
A virtual network emulates a phyisical one with switches, firewall, and load balacer. It comes on top of the physical network.
A VPC is logically or Phiysically isolated?
Logically
Name two services designed to operate in a VPC
EC2 and RDS
Name two services operating outside a customer VPC
Lambda and CloudWatch
Why should you build a new VPC for production environment ?
Because the default VPC already has connectivity conifgurations, You should configure your own depending on your configuration
How do you size a VPC ?
By allocating a range of IP
What is another name for a range of IP.
A CIDR block
What is a CIDR block?
It’s a Classeless Inter-Domain Routing. In other words, a range of IP
Is the size of the VPC easy to modify ?
No, this is why it’s important to assess the size correctly.
Min and Max size of an IPv4 VPC ?
Min of 16 IP adresses (/28)
Max of 65536 IP adresses (/16)
What is the dual stack configuraion for a VPC ?
Includes both IPv4 and IPv6 domains
What tool can I use to manage my adresses more easily ?
The IP address manager (IPAM)
Why opt for IPv6?
More adresses and also often better performance because IPV4 doesn’t do NAT
What should I be careful with when sizing a VPC with IPv4?
The cost because each IP is billed by the hour whether attached to a service or not.
What is a subnet ?
It’s a division of a VPC. They are linked to AZ. It’s also a segment of the range of IP in the VPC.
Can subnet CIDR block overlap ?
No
Are all IP in a subnet freely available to the customer?
No Amazon reserves 5 for its usage.
1. Network Adress
2. VPC local Router
3. DNS resolution
4. Future use (Undefined yet)
last. Network broadcast address
Two types of subnet
Public or Pricate depending on how accessible they are.
What should I consider for making ressources accessible through the internet ?
A subnet with an internet Gateway