VPC Peering Demo

In this tutorial, you’ll learn how to establish a VPC peering connection between two AWS VPCs so that their EC2 instances can communicate over the private AWS network:

Since VPCs are isolated by default, pinging from server1 to server2 will initially fail:

[ec2-user@ip-10-1-1-13 ~]$ ping 10.2.1.139
PING 10.2.1.139 (10.2.1.139) 56(84) bytes of data.
^C
--- 10.2.1.139 ping statistics ---
195 packets transmitted, 0 received, 100% packet loss

1. Create the VPC Peering Connection

1. Open the AWS VPC console and select Peering Connections → Create Peering Connection.
2. Name the connection VPC-A-to-VPC-B.
3. Under Requester, choose VPC-A.
4. Under Accepter, select your account and region, then choose VPC-B.
5. Click Create Peering Connection.

2. Accept the Peering Request

1. In Peering Connections, locate the new connection in Pending Acceptance.
2. Select it, then choose Actions → Accept Request.

Once accepted, its status changes to Active:

3. Update Route Tables

Each VPC needs a route pointing to the other VPC’s CIDR block through the peering connection:

1. In the VPC console, go to Route Tables.
2. Select the route table for VPC-A.

3. Under Routes, click Edit routes → Add route:
   • Destination: 10.2.0.0/16
   • Target: the peering connection (VPC-A-to-VPC-B)
4. Save changes.

5. Repeat these steps on VPC-B’s route table, adding a route to 10.1.0.0/16 via the same peering connection.

4. Verify Connectivity

Return to server1 and ping server2:

[ec2-user@ip-10-1-1-13 ~]$ ping 10.2.1.139
PING 10.2.1.139 (10.2.1.139) 56(84) bytes of data.
64 bytes from 10.2.1.139: icmp_seq=1 ttl=127 time=1.88 ms
64 bytes from 10.2.1.139: icmp_seq=2 ttl=127 time=1.43 ms
64 bytes from 10.2.1.139: icmp_seq=3 ttl=127 time=1.38 ms
^C
--- 10.2.1.139 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 1.382/1.563/1.882/0.187 ms

Your EC2 instances can now communicate across VPCs using the private AWS backbone.

Links and References

• AWS VPC Peering Documentation
• AWS Route Tables
• Terraform AWS VPC Peering Module