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Firewall Communication Matrix Checker

Compare a spreadsheet of expected traffic decisions with ordered IPv4 rules and export every mismatch. Work locally without uploading network information.

Runs entirely on your deviceNo uploads, accounts, cookies, or personal tracking.

Check required traffic against rules

Local processing · no input storage

Network tools
Tab-separated name, source IPv4, destination IPv4, tcp/udp/icmp, destination port (any for ICMP), expected permit/deny.
Five space-separated fields: permit/deny, ip/tcp/udp/icmp, source CIDR/any, destination CIDR/any, destination ports/any.

Uses the same simplified first-match model as IPv4 Traffic Rule Checker. No match means deny. No NAT, session state, source-port, vendor syntax, or live connectivity evaluation.

Text lists: up to 500 non-empty lines and 256 KiB per field. Tabular results: up to 5,000 rows.

Enter your data, then select check required traffic against rules.
1. Add your data

Enter your network data or load the worked example.

2. Choose the result

Check required traffic against rules and review the result and assumptions.

3. Save it locally

Copy the result or download it for your engineering workflow.

About this tool

Use Firewall Communication Matrix Checker without an upload

Compare a spreadsheet of expected traffic decisions with ordered IPv4 rules and export every mismatch. Work locally without uploading network information.

The operation runs in the current browser tab. Tool input is not included in aggregate analytics, and the standalone download makes no analytics requests.

Network toolsDeveloper tools