Which of the following are characteristics of Amazon VPC subnets? Choose 2 answers
A.
Each subnet spans at least 2 Availability Zones to provide a high-availability environment.
B.
Each subnet maps to a single Availability Zone.
C.
CIDR block mask of/25 is the smallest range supported.
D.
By default, all subnets can route between each other, whether they are private or public.
E.
Instances in a private subnet can communicate with the Internet only if they have an Elastic IP.
B D
1
0
Agree, B and D looks reasonable.
0
0
B & D
0
0
B & D
0
0
Why the other Answers are wrong.
Even though we know the right Answers it is sometimes good to know why the other Answers are wrong.
A. Is wrong because a subnet maps to a single AZ.
C. Is wrong because /28 is the smallest subnet, amazon takes first four and last addresses per subnet.
E. Is wrong because a private subnet needs a NAT appliance.
4
0
i feel wrong about D, public and private cant talk each other , unless we allowed.
0
0
I choose AE
0
0
A and E are wrong as explained by Bones Cisco.
Correct answer is B and D.
1
0
Agree with vladam
0
0
B and D.
0
0
B and D
0
0
B & D -> Though E is possible but the main subject used is the EC2 instance not the subnet.
0
0
Correct me if I am wrong, the smallest CIDR block is /29?
That can hold 7 different IPs, beside first 4 and last 1 reserved by AWS, there are still 2 IPs available.
https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing
0
0
Yes, seems correct. 5 IPs are used by AWS in every subnet leaving just 2 for a /29 network.
0
0
D is correct.
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Scenario3.html
The first entry is the default entry for local routing in the VPC; this entry enables the instances in the VPC to communicate with each other.
0
0
When you create a VPC, it spans all the Availability Zones in the region. After creating a VPC, you can add one or more subnets in each Availability Zone. When you create a subnet, you specify the CIDR block for the subnet, which is a subset of the VPC CIDR block. Each subnet must reside entirely within one Availability Zone and cannot span zones. Availability Zones are distinct locations that are engineered to be isolated from failures in other Availability Zones. By launching instances in separate Availability Zones, you can protect your applications from the failure of a single location. We assign a unique ID to each subnet.
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Subnets.html
0
0
B & D seems correct. E sounds close but its not true. Elastic IPs are required only for an inbound connection to a EC2 instance in a private subnet from external world. For the EC2 to communicate with the external network, a NAT instance is required.
1
0
B & D is correct answer….Each subnet assign to one AZ and all subnet are communicate with each other.
0
0
B & D makes sense
0
0
B & D are right, just did some digging around.
0
0