AWS Networking - Part VI: Subnet to Route Table Association

At this phase, we have attached subnets to their respective Availability Zones. Next, we will create subnet-specific route tables for both Public and Private subnets.

Figure 1-25: VPC Subnets: Select VPC.

 

Create Subnets

Navigate back to VPC Dashboard and click the Route Tables hyperlink either from the left or right columns. 

Figure 1-26: Subnet Route Table.

Figure 1-27 shows our current route tables. I have given the name NWKT-MAIN-RT (rtb-069ac98ac692271fe) for the auto generated main RT of VPC-VPC-01. The figure shows that there are no subnets associated with it. To proceed, click the Create route table button (18).

Figure 1-27: Subnet Route Table.

First, give the name to the route table. Then, select the correct VPC from the drop-down menu. After choosing the VPC, click the Create route table button. You can also create new tags for subnets. For example, the tag can describe the purpose of the route table. As an example, we can add Key = Purpose, Value = NWKT-WEB-SRV-RT. Note that each tag can have only one value. The maximum length for key/value pairs is 128/256 characters which are case-sensitive. 

Figure 1-28: Subnet Route Table.

Figure 1-29 shows that we have successfully created a new route table rtb-0fd4639034844c3ea | NWKT-PUB-RT. Now we can do the subnet association. At the moment, the route table has only one local route.

Figure 1-29: Subnet Route Table.

The Subnet association tab in the route table window (figure 1-30) shows that we haven't associate subnets to the route table. The next step is to associate our Public subnet 10.10.0.0/24 with this route table. Click the Edit subnet association button.

Figure 1-30: Subnet Route Table.

Select the subnet NWKT-Pub-euw2c and click the Save association button.

Figure 1-31: Subnet Route Table.

Figure 1-32 shows that now the subnet NWKT-Pub-euw2c (10.10.0.0/24) is associated with route table NWKT-PUB-RT. The Private subnet NWKT-Pri-euw2a is still without explicit association. As a next step, we associate it with the route table  NWKT-PRI-RT. Figure 1-33 shows the route table association after associating both subnects with correct route tables.

Figure 1-32: Subnet Route Table.

Figure 1-33: Subnet Route Table.

In the next part we will associate subnet to route table using AWS CloudFormation.