Our fifth post on the AWS Solutions Architect Associate certification preparation topic. Hope you have enjoyed the previous posts in this series
where we discussed many important topics including EC2, S3, Databases etc…
[ Disclaimer : This is not a complete training material for the certification. This is just random (short) notes which we captured from course curricula, which will help the readers for their final revision/rewind before appearing for the exam. We do not offer any guarantee in passing the exam with this content ]
Now, let’s continue
Note : ELBs do not have a pre-defined IP address, you route to them using route53.
1. Simple routing policy – Can have multiple entries against one name and the policy picks the IPs randomly during the request.
2. Weighted Routing policy – We can set weightage for each record (individual host records to be created) and the IO request will be given priority in that order. [We can create healthchecks for the instances and routing policy omits the records having healthcheck issues]
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3. Latency based policy – Route53 decides the DNS records/instances based on the least network latency.
4. Failover routing policy – We can define active and passive records. Healthcheck monitors the active
5. Geolocation routing policy – Based on the location of users queries DNS, the DNS record/EC2 instance will be used. Not same as latency
6. Geoproximity routing policy – Complicated one. Allows the access based on the location of the users and resources.Bias(keyword)
7. Multivalue routing policy – similar to simple routing policy, but allows healthcheck for multiple instances.
VPC (Virtual Private Cloud)
Virtual Private Cloud allows the segregation of the network allowing you to create your own logically isolated AWS environment. Complete control of the network settings (including ip address,subnet,route tables,internet gateways etc…). Can seperate hosts to private (without internet) and public (with internet) segments, adding up security. can create a VPN connection with the VPC and use the AWS as an office/datacenter extension.
* Launch instances into a chosen subnet
* Assigning custom IP address ranges in each subnet
* Configuring route tables between subnets
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* Create internet gateway and attach to our VPC
* Better security control over AWS resources
* instance security groups
* Subnet Network ACLs.
Default VPC allows easy instance deployments. All subnets in def VPC will have route to the internet. Each EC2 instance will have both private and public IPs.
VPC Peering : allows direct communication with hosts in another VPC. Peering can be done with VPCs in another AWS account and another region also. No Transitive peering (direct peering between VPCs is required)
1 AZ can have one or more Subnets, but 1 subnet can’t span across AZs.
Only 1 Internet Gateway per VPC.
We are not done with VPC yet, we will add additional notes in the next post in this series. Hope these contents are helping you in your preparation.
Feel free to share your feedback/suggestions in the comments section.