Batfish Configuration Analysis
MCP Server
- Source: Built-in (mcp-servers/batfish-mcp/)
- Command:
python3 -u mcp-servers/batfish-mcp/batfish_mcp_server.py(stdio transport) - Requires: Batfish Docker container running,
BATFISH_HOSTandBATFISH_PORTenvironment variables - Python: 3.10+
- Dependencies:
pybatfish,mcp[cli],python-dotenv
Available Tools (8)
| Tool | Parameters | What It Does |
|---|---|---|
batfish_upload_snapshot | snapshot_name, configs/config_path, network | Upload device configs to Batfish and create a named snapshot |
batfish_validate_config | snapshot_name, network | Validate configs with per-device pass/fail status, vendor detection, warnings |
batfish_test_reachability | snapshot_name, src_ip, dst_ip, protocol, dst_port | Test if traffic can flow between two endpoints with full path trace |
batfish_trace_acl | snapshot_name, device, filter_name, src_ip, dst_ip, protocol, dst_port | Trace a packet through ACL rules to find matching permit/deny rule |
batfish_diff_configs | reference_snapshot, candidate_snapshot, include_routes, include_reachability | Compare two snapshots for route and reachability differences |
batfish_check_compliance | snapshot_name, policy_type | Check configs against compliance policies (6 built-in policy types) |
batfish_list_snapshots | network | List all available snapshots |
batfish_delete_snapshot | snapshot_name, network | Delete a snapshot |
Workflow: Pre-Change Validation
When a user wants to validate configurations before deployment:
- Upload configs:
batfish_upload_snapshotwith inline configs dict or path to config directory - Validate:
batfish_validate_configto check parse status, vendor detection, warnings/errors - Test reachability:
batfish_test_reachabilityfor critical traffic paths - Check compliance:
batfish_check_complianceagainst organizational policies - Report: Structured pass/fail results with specific findings
- GAIT: All operations automatically logged
Example: Validate Before Deploy
bash# Upload proposed configs batfish_upload_snapshot snapshot_name="pre-change-site-a" config_path="/path/to/configs/" # Validate parse status batfish_validate_config snapshot_name="pre-change-site-a" # Test critical path batfish_test_reachability snapshot_name="pre-change-site-a" src_ip="10.1.1.1" dst_ip="10.2.2.1" protocol="TCP" dst_port=443 # Check compliance batfish_check_compliance snapshot_name="pre-change-site-a" policy_type="interface_descriptions"
Workflow: Change Impact Analysis
When comparing before/after configurations:
- Upload "before" snapshot:
batfish_upload_snapshotwith current configs - Upload "after" snapshot:
batfish_upload_snapshotwith proposed configs - Diff:
batfish_diff_configsto find route and reachability differences - Investigate: Use
batfish_trace_aclon any newly denied traffic - Report: Structured diff showing added/removed/changed routes and flows
Workflow: ACL Troubleshooting
When investigating access control issues:
- Upload configs:
batfish_upload_snapshotwith device configs - Trace packet:
batfish_trace_aclwith device, ACL name, and packet headers - Review: Identify matching rule, line number, permit/deny action
- Test alternatives: Modify config, re-upload, trace again
Integration with Other Skills
| Skill | Integration |
|---|---|
| pyats-config-mgmt | Validate configs with Batfish before pushing via pyATS |
| gait-session-tracking | All Batfish operations automatically logged |
| servicenow-change-workflow | Reference Batfish validation in change request evidence |
| fwrule-analyzer | Complement ACL trace with cross-vendor overlap analysis |
| cml-lab-lifecycle | Validate CML lab configs with Batfish analysis |
Important Rules
- All operations are strictly read-only -- Batfish analyzes uploaded configs, never modifies network devices
- GAIT audit mandatory -- All operations logged automatically
- Snapshots are ephemeral -- Batfish manages snapshot lifecycle; use GAIT for persistent records
- Multi-vendor -- Supports Cisco IOS/IOS-XE/NX-OS, JunOS, Arista EOS, Palo Alto, F5
Error Handling
- BATFISH_UNREACHABLE: Verify Docker container is running (
docker ps | grep batfish) - SNAPSHOT_NOT_FOUND: Use
batfish_list_snapshotsto see available snapshots - INVALID_INPUT: Check configs dict is non-empty or config_path exists
- DEVICE_NOT_FOUND: Use
batfish_validate_configto list devices in snapshot - FILTER_NOT_FOUND: Verify ACL/filter name exists on the specified device
Environment Variables
BATFISH_HOST-- Batfish hostname (default: localhost)BATFISH_PORT-- Batfish port (default: 9997)BATFISH_NETWORK-- Default network name (default: netclaw)
