Route tables configuration in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a route table in AWS?

A route table in AWS is a set of rules, called routes, that determine where network traffic from your subnet or gateway is directed.

beginner

How do you associate a route table with a subnet?

You associate a route table with a subnet by specifying the subnet in the route table's associations. This controls the routing for that subnet's traffic.

intermediate

What is the purpose of a default route (0.0.0.0/0) in a route table?

A default route (0.0.0.0/0) sends all traffic destined for addresses not explicitly listed in the route table to a specified target, like an internet gateway, enabling internet access.

intermediate

Can a subnet be associated with multiple route tables at the same time?

No, a subnet can only be associated with one route table at a time. This ensures clear routing rules for that subnet.

beginner

What happens if a route table has no route for a destination IP?

If a route table has no route for a destination IP, the traffic is dropped because AWS does not know where to send it.

What does a route table control in AWS?

A Storage allocation

B User permissions

C CPU usage

D Where network traffic is directed

A route table controls where network traffic from subnets or gateways is directed.

Which target is commonly used in a route for internet access?

A Internet Gateway

B Virtual Private Gateway

C Elastic Load Balancer

D Security Group

An Internet Gateway is used as a target in a route to allow internet access.

Can a subnet have multiple route tables associated simultaneously?

A No, only one

B Yes, always

C Only in VPC peering

D Only for public subnets

A subnet can only be associated with one route table at a time.

What does the route destination 0.0.0.0/0 represent?

A Local network only

B All IPv4 addresses

C IPv6 addresses

D Private IP addresses

0.0.0.0/0 represents all IPv4 addresses, used as a default route.

What happens if no route matches the destination IP in a route table?

A Traffic is sent to the internet

B Traffic is sent to the default subnet

C Traffic is dropped

D Traffic is logged and retried

If no route matches, AWS drops the traffic because it has no path to send it.

Explain how route tables control network traffic in an AWS VPC.

Think about how traffic knows where to go inside and outside the VPC.

Describe the role of the default route 0.0.0.0/0 in a route table and when you would use it.

Consider what happens when traffic is destined for an unknown IP.