ANS-C01 Network Design Practice Question

A company has a VPC with a CIDR of 10.0.0.0/16. They want to connect this VPC to a second VPC with CIDR 10.1.0.0/16 using VPC Peering. The VPCs are in the same account and Region. What is the minimum number of route table entries needed in each VPC to enable full bidirectional communication?

⚠ Common exam trap

Candidates often assume VPC peering automatically handles routing, similar to a VPN or direct connect, but AWS requires explicit route table entries for each direction.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

One route in each VPC's route table

VPC peering requires a route in each VPC's route table pointing to the CIDR of the peer VPC, using the peering connection as the target. The local VPC's CIDR is automatically added to the route table by default, so only one additional route per VPC is needed for full bidirectional communication.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Two routes in each VPC's route table: one for the local CIDR and one for the peer CIDR
Why it's wrong here
Local CIDR routes are automatically added; only peer CIDR needs explicit route.
✗
No routes are needed because VPC Peering automatically enables communication
Why it's wrong here
Explicit routes must be added to route tables.
✓
One route in each VPC's route table
Why this is correct
Each VPC needs a route to the peer VPC's CIDR via the peering connection.
✗
One route in only one VPC's route table
Why it's wrong here
Both VPCs need routes to the peer CIDR for bidirectional communication.

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ANS-C01 Network Design Practice Question

Why each option matters

Option-by-option breakdown

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