General Collection Flashcards
What is a CIDR block?
Classless Inter-Domain Routing, it is a range of private IPv4 addresses.
What are bastion hosts?
A bastion host is a host computer or a “jump server” used to allow SSH access to your EC2 instances from an outside network.
What is a hypervisor?
A hypervisor is a computer software, firmware or hardware that creates and runs virtual machines.
How to choose a suitable type of a elastic load balancer? (classic, network or application)
If you need flexible application management and TLS termination then we recommend that you use Application Load Balancer. If extreme performance and static IP is needed for your application then we recommend that you use Network Load Balancer. If your application is built within the EC2 Classic network then you should use Classic Load Balancer.
Describe and explain the differences between the pricing types of the EC2 instances
Dedicated hosts: a physical server is dedicated to running the EC2 instances.
On-demand: pay by the hours and resources used by the instance.
Spot instances: requests are only made to the available EC2 instances.
Reserved instances: instance(s) are reserved on a one to a three-year term plan.
What is a NAT gateway?
Network address translation gateway, is used to enable instances present in a private subnet to help connect to the internet or AWS services.
What is an autoscaling group?
An autoscaling group is a collection of EC2 instances where the number of instances can be adjusted based on the number of requests, traffic and load. Users can customize the metrics such as the minimum and maximum instance numbers and the conditions for the group should scale in and out.
