Is the path exact?
Source, destination, direction, transport, and service should describe one required communication path.
Firewall Rule Planner
This planner does not configure a firewall. It produces a change record you can review before translating it into a vendor-specific rule.
Draft values remain in this browser. Use examples instead of sensitive production details on a shared device.
SourceAllow TCP 443Destination
Inbound traffic path
Build a rule another person can review
The planner separates traffic scope, accountability, and verification. Required fields prevent an output that is only a source, destination, and port.
What a reviewer should challenge
A good record makes uncertainty visible before a broad or permanent rule reaches production.
Is the access narrower?
Compare the request with existing broader rules, object groups, state behavior, and implicit platform policy.
Can the result be proved?
Test one intended source and one source that must remain blocked. Keep the matching rule and log evidence.
Will the rule be retired?
Ownership, approval, expiry, and rollback stop a temporary exception from becoming unexplained permanent access.
Example: documenting one inbound administration rule
A vendor needs temporary access to an administration service. A reviewable record names the vendor source address, one destination, the exact protocol and port, the system owner, the maintenance purpose, an allowed test, a blocked-source test, and an expiry immediately after the work window.
After the record is approved
Translate the approved record into the firewall's native objects and syntax. Check for broader existing rules that may make the new entry irrelevant, place the rule according to platform behavior, and preserve a rollback command or configuration checkpoint.
Before adding a proposed entry, check the ordered policy for duplicates, contradictions, and shadowed scope with the firewall rule conflict checker .
Review how firewall state and rule matching work when direction or return traffic is unclear.
After approval and implementation, use the controlled firewall test workflow to collect evidence for one allowed and one blocked case.
What the planner cannot validate
The planner documents a decision. It cannot inspect the deployed policy or know how a specific firewall evaluates the final configuration.
- The planner does not validate whether an address, service, or owner is genuine.
- It does not account for every vendor's rule ordering, object groups, identity controls, or implicit policy.
- Generated text is a review record, not authorization or a deployed security control.
Evidence required before and after deployment
| Stage | Required record | Decision it supports |
|---|---|---|
| Before change | Owner, purpose, exact path, approval, and current behavior | Whether the exception is necessary and narrow |
| During change | Configuration diff, implementer, time, and rollback checkpoint | What changed and how to reverse it |
| After change | Allowed test, blocked test, logs, counters, and review date | Whether the intended path works without broadening access |
Firewall rule planning questions
Why include an expiry date?
Temporary rules often become permanent when no removal condition is recorded. Expiry creates a clear review trigger.
Why test a blocked source?
A working allowed connection proves the service is reachable, but not that the source restriction or surrounding deny policy works.
Review method: NIST SP 800-41 Rev. 1, Guidelines on Firewalls and Firewall Policy.