Answers: <p>Are they in the same VPC? If yes it should just work as the VPC CIDR route will take care of all the subnets intercommunication. </p>
  
Answers: CC BY-SA 4.0
Answers: 2019-08-09T21:15:43.957Z
Answers: yes, they are on the same VPC, but if that is the case, then why do I need to connect private a public subnets? take into account I'm not using the default routing table. All subnets currently have their own routing table.
Answers: Manatax
Answers: CC BY-SA 4.0
Answers: 2019-08-09T21:36:06.923Z
Answers: I see, I'm not connecting the private to the public, but the private to the NAT in the public...
Answers: Manatax
Answers: CC BY-SA 4.0
Answers: 2019-08-09T21:09:04.387Z
Answers: 2019-08-09T21:09:04.387Z
Answers: MLu
Body: <p>I'm testing some cloudformation infrastructure templates, and I noticed that most of the examples include routing tables to connect private subnets to public subnets, but my question then is:</p>
  
  <p>if two private subnets exist in different AZs (and are attached to individual routing tables) and the resources within them may need to access a resource on the other subnet (for example a private service on the subnet 1 accessing a database on the subnet 2)</p>
  
  <ol>
  <li><strong>Should I create a route to connect the two private subnets in each of their routing tables?</strong></li>
  <li><strong>Would it be a better practice to attach both subnets to a single shared routing table (both CIDRs are contiguous)?</strong></li>
  </ol>
  
Comments: CC BY-SA 4.0
Comments: 2019-08-09T21:16:03.627Z
Comments: Both subnets are on the same VPC
Comments: Manatax
Tags: <amazon-web-services><networking>
Title: aws - Connect two private subnets?
UserDisplayName: Manatax
ThreadText: # aws - Connect two private subnets?
  
  (Asked by: username_0 on 2019-08-09)
  
  I'm testing some cloudformation infrastructure templates, and I noticed that most of the examples include routing tables to connect private subnets to public subnets, but my question then is:
  
  if two private subnets exist in different AZs (and are attached to individual routing tables) and the resources within them may need to access a resource on the other subnet (for example a private service on the subnet 1 accessing a database on the subnet 2)
  
  1. **Should I create a route to connect the two private subnets in each of their routing tables?**
  2. **Would it be a better practice to attach both subnets to a single shared routing table (both CIDRs are contiguous)?**
  
  **Tags:** amazon-web-services, networking
  
  > **Comments:**
  > **username_0**: Both subnets are on the same VPC  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2019-08-09. Score: 2 | Accepted answer
  
  Are they in the same VPC? If yes it should just work as the VPC CIDR route will take care of all the subnets intercommunication.
  
  > **Comments:**
  > **username_0**: yes, they are on the same VPC, but if that is the case, then why do I need to connect private a public subnets? take into account I'm not using the default routing table. All subnets currently have their own routing table.  
  > **username_0**: I see, I'm not connecting the private to the public, but the private to the NAT in the public...  
  
  ---
  
  