Creating the Route Tables

Route tables define the routing paths between resources in private and public subnets and the Internet.

  1. Run the following command to create a route table and retrieve its ID:
    aws ec2 create-route-table \ 
    --vpc-id <VpcId> \ 
    | jq -r '.RouteTable.RouteTableId'
  1. Run the command in Step 1 a second time, to create another route table and retrieve its ID.

Example input and output:

aws ec2 create-route-table \
--vpc-id vpc-0143197ca9bd9c117 \
 jq -r '.RouteTable.RouteTableId'
rtb-0deda70daa09ca3bfw
  1. Tag the first route table as private. Run the command:
    aws ec2 create-tags --resources <route table ID> \
    --tags Key=Name,Value=<route table name indicating private>

Example:

aws ec2 create-tags \
--resources rtb-0deda70daa09ca3bf \
--tags Key=Name,Value=srgdemo-private-route-table

  1. Repeat Step 3 for the second route table, with the --tags value indicating public instead of private.

Associating the Route Tables to Subnets

The route tables will now need to be associated to the subnets you have created.

  1. Select one of your public subnets.
  2. Associate the public route table to the selected public subnet by running the command:
    aws ec2 associate-route-table \
    --route-table-id <public route table ID> \
    --subnet-id <public subnet ID>
  3. Repeat the command in Step 2 for each of the other two public subnets.

To associate the route tables to your private subnets:

  1. Select one of your private subnets.
  2. Associate the private route table to the selected private subnet by running the command:
    aws ec2 associate-route-table \
    --route-table-id <private route table ID> \
    --subnet-id <private subnet ID>
  3. Repeat the command in Step 2 for each of the other two private subnets.

Example input and output:

aws ec2 associate-route-table \
--route-table-id rtb-0deda70daa09ca3bf \
--subnet-id subnet-0fb2ebb5882c061f0
{
   "AssociationId":"rtbassoc-781d0d1a",
   "AssociationState":{
      "State":"associated"
   }
}

Adding the NAT Gateway Route Path to the Private Route Table

  1. Run the following command:
    aws ec2 create-route \
    --route-table-id <private route table Id> \
    --destination-cidr-block "0.0.0.0/0" \
    --nat-gateway-id <NAT GW Id>
  1. The command will return the creation status. A status of true indicates that the request succeeded.

Example input and output:

aws ec2 create-route \
--route-table-id rtb-0deda70daa09ca3bf \
--destination-cidr-block "0.0.0.0/0" \
--nat-gateway-id nat-013416dad7b7656ea
{
   "Return":true
}

Adding the Internet Gateway Route Path to the Public Routing Table

  1. Run the following command:
    aws ec2 create-route \
    --route-table-id <public route table Id> \
    --destination-cidr-block "0.0.0.0/0" \
    --gateway-id <Internet Gateway Id>

Example:

>aws ec2 create-route \
--route-table-id rtb-0fa9f294a3743c9aa \
--destination-cidr-block "0.0.0.0/0" \
--gateway-id igw-0ddcfa7511fe10b43

Next Step: Creating Security Groups