If VPC traffic stopped working after you removed AWS Network Firewall, restore the affected route tables to the paths intended by your original network design. Remove any routes that still target the deleted firewall endpoint, then check both request and response paths in every affected Availability Zone. There is no universal replacement route: use your pre-change configuration or architecture to determine the right targets.
Why traffic can break after firewall removal
Network Firewall endpoints can be inserted into VPC routing paths. Removing a firewall does not automatically tell you what route should replace it. A route table that still points to a removed endpoint can disrupt traffic, and route-table references to an endpoint can also block firewall or endpoint-association cleanup. AWS’s firewall deletion procedure and DeleteFirewall API reference require removing relevant associations and route references before deletion is complete.
As an Amazon Associate I earn from qualifying purchases.
AWS’s getting-started tutorial demonstrates returning the internet gateway and customer-subnet route tables to their earlier configurations and removing the endpoint route configuration. That is an example, not a universal route recipe: a centralized inspection VPC, Transit Gateway, or other design may use different route tables and targets.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Restore routing in a safe order
- Map the affected flow. Record the source and destination subnets, the direction of traffic, and whether the path involves an internet gateway, Transit Gateway, or another appliance. Identify the subnet route tables and Availability Zones involved.
- Find firewall endpoint routes. Inspect every relevant route table for destinations whose target references the removed firewall endpoint. Check subnet associations and endpoint mappings in each Availability Zone, not just the route table you first noticed.
- Determine the intended target. Compare the current entries with the recorded pre-change configuration, change records, infrastructure-as-code state, or documented network design. Do not substitute a generic default route or guess at a target.
- Restore the designed path. Replace stale endpoint targets with the intended route targets for the affected destinations. For the simple internet-gateway example in AWS’s tutorial, restore the earlier internet gateway and customer-subnet route-table configuration and remove the firewall endpoint route configuration.
- Check the return path. Trace response traffic as well as requests. If Network Firewall remains in another part of the design and stateful inspection is required, AWS says both directions must use the same firewall endpoint; asymmetric routing is unsupported for that use.
- Validate each affected flow. Confirm the route-table associations and connectivity for the relevant subnets and Availability Zones. If the path is still unclear, use VPC Reachability Analyzer or available Network Firewall flow, alert, or logging data to investigate.
If firewall or endpoint cleanup is blocked
Look for route-table references to the endpoint before retrying deletion. AWS’s DeleteVpcEndpointAssociation API reference says to remove the endpoint from the relevant Availability Zone’s route tables before removing the association. The endpoint-failure troubleshooting guide identifies a route-table VPCE reference as a reason deletion can fail and recommends removing the endpoint target and retrying.
#1 Best Overall
If an endpoint reports an error or failure, check its status message in the AWS console or through DescribeFirewall or DescribeVpcEndpointAssociation. AWS notes that a status message can take as many as 15 minutes to appear, so its absence immediately after a change does not establish that the endpoint is healthy.
How to verify the routing diagnosis
- Compare routes by destination and target. Confirm that the affected destination now points to the target required by the design, rather than a removed endpoint.
- Check subnet and Availability Zone coverage. Verify route-table associations and endpoint mappings for every subnet and Availability Zone used by the flow.
- Trace both directions. A successful request route alone is not enough. Confirm the response follows the intended path too. AWS’s general troubleshooting guidance explains that Network Firewall does not support asymmetric routing and recommends the endpoint closest to the client in both directions when firewall inspection is used.
- Use diagnostic evidence. VPC Reachability Analyzer can help assess reachability; Network Firewall analyzers and logging can help clarify observed traffic behavior.
AWS says firewall changes normally propagate within minutes, though temporary inconsistencies can last seconds, in its firewall management guidance. Those general propagation notes are not a guaranteed recovery time for an individual route-table repair; validate the actual flow after correcting routes.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Free tools Windows power users keep installed
One-click scans. No signup required.
