Network traffic may be affected after you enable VPC Firewall. However, network traffic is not affected after you enable Internet Firewall.

When you create a VPC firewall, Cloud Firewall automatically creates routes so that traffic can be directed to the VPC firewall. Network jitter may occur when traffic is directed to the VPC firewall.

Before you enable VPC Firewall, we recommend that you evaluate your VPCs from the following aspects:
  • Whether your VPCs support automatic retransmission. If your VPCs use TCP-based networking, they support automatic retransmission.
  • Whether the persistent connections of your VPCs support reconnection.
  • Whether the traffic between your VPCs is large.
Note We recommend that you enable VPC Firewall during off-peak hours.