NetBox Reconciliation

Compare NetBox (source of truth) intent against live device state collected via pyATS. Identify discrepancies, classify them by type and severity, and ticket critical findings in ServiceNow.

Golden Rule

NetBox is READ-WRITE. The MCP has full API access to create and update devices, IPs, interfaces, VLANs, and cables. However, during reconciliation, discrepancies are reported and ticketed first — they are NEVER auto-corrected without explicit human approval. NetBox is the intended state. If reality differs from NetBox, either the network is wrong or NetBox needs updating. NetClaw can update NetBox when explicitly authorized by the operator.

How to Call the Tools

NetBox MCP Server

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" TOOL_NAME '{"param":"value"}'

pyATS MCP Server (for live device state)

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" TOOL_NAME '{"param":"value"}'

NetBox Tools Reference

Tool	Purpose	Key Parameters
netbox_get_objects	Bulk query objects by type	object_type, filters (dict), limit, brief
netbox_get_object_by_id	Get single object by ID	object_type, object_id
netbox_search_objects	Global text search	query, object_types
netbox_get_changelogs	Audit trail of NetBox changes	filters

Object Types

Object Type	Contains
dcim.devices	Devices: name, role, platform, site, status
dcim.interfaces	Interfaces: name, type, enabled, MAC, MTU, mode (access/tagged), untagged_vlan, tagged_vlans
ipam.ip-addresses	IP addresses: address (CIDR), assigned_object, status, role
dcim.cables	Physical cables: A-side termination, B-side termination, type, length
ipam.vlans	VLANs: vid, name, site, tenant, status
ipam.prefixes	Prefixes: prefix (CIDR), VRF, site, status
dcim.sites	Sites: name, region, physical_address

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Discrepancy Types

Code	Name	Severity	Description
IP_DRIFT	IP Address Drift	CRITICAL	Device IP differs from NetBox assignment
MISSING_INTERFACE	Missing Interface	HIGH	Interface exists in NetBox but not on device (or vice versa)
UNDOCUMENTED_LINK	Undocumented Link	HIGH	CDP/LLDP shows a neighbor connection not documented in NetBox cables
CABLE_MISMATCH	Cable Mismatch	HIGH	NetBox cable endpoints do not match CDP/LLDP neighbor data
VLAN_MISMATCH	VLAN Mismatch	MEDIUM	Device VLAN assignment differs from NetBox
STATUS_MISMATCH	Interface Status Mismatch	MEDIUM	NetBox shows enabled but device shows down (or vice versa)
MTU_MISMATCH	MTU Mismatch	LOW	Device MTU differs from NetBox interface MTU

Severity order: CRITICAL > HIGH > MEDIUM > LOW

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Full Reconciliation Workflow

Step 1: Collect NetBox Intent

1A: Get Device Inventory from NetBox

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" netbox_get_objects '{"object_type":"dcim.devices","filters":{"status":"active"},"brief":true}'

This returns all active devices. Match against the pyATS testbed to determine which devices can be reconciled.

1B: Get Interfaces from NetBox (per device)

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" netbox_get_objects '{"object_type":"dcim.interfaces","filters":{"device":"R1"}}'

Extract per interface:

• Name, type, enabled status
• MTU, MAC address
• Mode (access/tagged), untagged VLAN, tagged VLANs
• Description, label

1C: Get IP Addresses from NetBox (per device)

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" netbox_get_objects '{"object_type":"ipam.ip-addresses","filters":{"device":"R1"}}'

Extract per IP:

• Address (CIDR notation)
• Assigned interface
• Status (active, reserved, deprecated)
• Role (primary, secondary, loopback, VIP)

1D: Get Cables from NetBox (per device)

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" netbox_get_objects '{"object_type":"dcim.cables","filters":{"device":"R1"}}'

Extract per cable:

• A-side: device, interface
• B-side: device, interface
• Cable type, length, color

1E: Get VLANs from NetBox

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" netbox_get_objects '{"object_type":"ipam.vlans","filters":{"site":"main-site"}}'

Step 2: Collect Live Device State

2A: Get Interfaces from Device

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show ip interface brief"}'

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show interfaces"}'

Extract per interface:

• Name, admin status (up/down), protocol status (up/down)
• IP address, subnet mask
• MTU, speed, duplex
• Description

2B: Get IP Addresses from Device

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show ip interface"}'

Extract per interface:

• Primary IP address and mask
• Secondary IP addresses (if any)

2C: Get Neighbor Data from Device

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show cdp neighbors detail"}'

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show lldp neighbors detail"}'

Extract per neighbor:

• Local interface -> Remote device, remote interface
• Remote platform, remote IP

2D: Get VLAN Data from Device

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show vlan brief"}'

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show interfaces switchport"}'

Step 3: Diff Engine

Compare NetBox intent vs device reality for each discrepancy type.

3A: IP_DRIFT Detection

For each interface with an IP in NetBox:

NetBox:  GigabitEthernet1 -> 10.1.1.1/30
Device:  GigabitEthernet1 -> 10.1.1.5/30
Result:  IP_DRIFT (CRITICAL) - GigabitEthernet1: NetBox=10.1.1.1/30, Device=10.1.1.5/30

Comparison logic:

1. Get all IPs from NetBox for device R1 (Step 1C)
2. Get all IPs from device R1 (Step 2B)
3. For each NetBox IP assignment:
   • Find the matching interface on the device
   • Compare the IP address and prefix length
   • If different -> IP_DRIFT (CRITICAL)
   • If interface exists but has no IP -> IP_DRIFT (CRITICAL)
4. For each device IP not in NetBox -> IP_DRIFT (CRITICAL) - undocumented IP

3B: MISSING_INTERFACE Detection

NetBox:  GigabitEthernet3 (enabled)
Device:  GigabitEthernet3 does not exist
Result:  MISSING_INTERFACE (HIGH) - GigabitEthernet3 exists in NetBox but not on device

Comparison logic:

1. Get interface list from NetBox (Step 1B)
2. Get interface list from device (Step 2A)
3. For each NetBox interface not found on device -> MISSING_INTERFACE (HIGH)
4. For each device interface not found in NetBox -> MISSING_INTERFACE (HIGH) with note "undocumented"
5. Filter out virtual/internal interfaces that are platform-specific (Null0, NVI0, etc.)

3C: UNDOCUMENTED_LINK Detection

CDP:     R1:GigabitEthernet2 -> SW1:GigabitEthernet0/1
NetBox:  No cable record for R1:GigabitEthernet2
Result:  UNDOCUMENTED_LINK (HIGH) - R1:Gi2 -> SW1:Gi0/1 discovered via CDP but not in NetBox

Comparison logic:

1. Get CDP/LLDP neighbors from device (Step 2C)
2. Get cable records from NetBox (Step 1D)
3. For each CDP/LLDP neighbor:
   • Search NetBox cables for a matching A-side/B-side pair
   • If no cable exists -> UNDOCUMENTED_LINK (HIGH)

3D: CABLE_MISMATCH Detection

NetBox:  R1:GigabitEthernet1 -> R2:GigabitEthernet1
CDP:     R1:GigabitEthernet1 -> R3:GigabitEthernet0
Result:  CABLE_MISMATCH (HIGH) - R1:Gi1 NetBox says R2:Gi1 but CDP says R3:Gi0

Comparison logic:

1. For each NetBox cable involving this device:
   • Look up the corresponding CDP/LLDP entry for the local interface
   • Compare the remote device and remote interface
   • If different -> CABLE_MISMATCH (HIGH)

3E: VLAN_MISMATCH Detection

NetBox:  GigabitEthernet2 untagged_vlan=10
Device:  GigabitEthernet2 access vlan 20
Result:  VLAN_MISMATCH (MEDIUM) - GigabitEthernet2: NetBox VLAN=10, Device VLAN=20

Comparison logic:

1. Get interface VLAN assignments from NetBox (Step 1B, look at untagged_vlan and tagged_vlans)
2. Get interface switchport data from device (Step 2D)
3. Compare access VLAN, trunk allowed VLANs, and native VLAN
4. If different -> VLAN_MISMATCH (MEDIUM)

3F: STATUS_MISMATCH Detection

NetBox:  GigabitEthernet3 enabled=true
Device:  GigabitEthernet3 administratively down
Result:  STATUS_MISMATCH (MEDIUM) - GigabitEthernet3: NetBox=enabled, Device=admin-down

3G: MTU_MISMATCH Detection

NetBox:  GigabitEthernet1 MTU=9000
Device:  GigabitEthernet1 MTU=1500
Result:  MTU_MISMATCH (LOW) - GigabitEthernet1: NetBox MTU=9000, Device MTU=1500

Step 4: Generate Reconciliation Report

Produce a severity-sorted discrepancy table:

NetBox Reconciliation Report - R1
Date: YYYY-MM-DD HH:MM UTC
NetBox Device: R1 | pyATS Device: R1 (devnetsandboxiosxec8k.cisco.com)

CRITICAL:
  [C-001] IP_DRIFT: GigabitEthernet1 - NetBox=10.1.1.1/30, Device=10.1.1.5/30
  [C-002] IP_DRIFT: Loopback0 - NetBox=1.1.1.1/32, Device=2.2.2.2/32

HIGH:
  [H-001] UNDOCUMENTED_LINK: Gi2 -> SW1:Gi0/1 (CDP) - no cable in NetBox
  [H-002] MISSING_INTERFACE: GigabitEthernet4 in NetBox but not on device

MEDIUM:
  [M-001] VLAN_MISMATCH: Gi3 - NetBox VLAN=10, Device VLAN=20
  [M-002] STATUS_MISMATCH: Gi5 - NetBox=enabled, Device=admin-down

LOW:
  [L-001] MTU_MISMATCH: Gi1 - NetBox MTU=9000, Device MTU=1500

Summary: 2 Critical | 2 High | 2 Medium | 1 Low
Overall: CRITICAL - immediate attention required

Step 5: Ticket Critical Discrepancies

For each CRITICAL discrepancy, open a ServiceNow incident:

python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" create_incident '{"short_description":"NetBox Drift: IP_DRIFT on R1 GigabitEthernet1","description":"NetBox reconciliation detected IP address drift on R1 GigabitEthernet1.\n\nNetBox intent: 10.1.1.1/30\nDevice reality: 10.1.1.5/30\n\nThis is a CRITICAL discrepancy. Either the device configuration is incorrect and needs remediation, or NetBox needs to be updated to reflect the current state.\n\nDiscovery method: NetClaw automated reconciliation\nDate: YYYY-MM-DD HH:MM UTC","urgency":"2","impact":"2","category":"Network"}'

For HIGH discrepancies, create incidents at lower urgency:

python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" create_incident '{"short_description":"NetBox Drift: UNDOCUMENTED_LINK R1:Gi2 -> SW1:Gi0/1","description":"NetBox reconciliation found a physical link (via CDP) between R1:GigabitEthernet2 and SW1:GigabitEthernet0/1 that has no cable record in NetBox.\n\nAction required: Add cable record to NetBox or investigate if this link is authorized.\n\nDiscovery method: NetClaw automated reconciliation","urgency":"3","impact":"3","category":"Network"}'

Step 6: Generate Markmap Drift Summary

Create a visual mind map of all discrepancies for human review:

python3 $MCP_CALL "node $MARKMAP_MCP_SCRIPT" markmap_generate '{"markdown_content":"# NetBox Reconciliation - R1\n## CRITICAL\n### IP_DRIFT\n- Gi1: NetBox=10.1.1.1/30 vs Device=10.1.1.5/30\n- Lo0: NetBox=1.1.1.1/32 vs Device=2.2.2.2/32\n## HIGH\n### UNDOCUMENTED_LINK\n- Gi2 -> SW1:Gi0/1 (no cable in NetBox)\n### MISSING_INTERFACE\n- Gi4 (in NetBox, not on device)\n## MEDIUM\n### VLAN_MISMATCH\n- Gi3: NetBox VLAN=10 vs Device VLAN=20\n### STATUS_MISMATCH\n- Gi5: NetBox=enabled vs Device=admin-down\n## LOW\n### MTU_MISMATCH\n- Gi1: NetBox=9000 vs Device=1500"}'

Step 7: Record in GAIT

python3 $MCP_CALL "python3 -u $GAIT_MCP_SCRIPT" gait_record_turn '{"user_text":"Reconcile NetBox source of truth against R1 live state","assistant_text":"NetBox reconciliation complete for R1.\n\nDiscrepancies found: 2 CRITICAL, 2 HIGH, 2 MEDIUM, 1 LOW\n\nCRITICAL:\n- IP_DRIFT: Gi1 (10.1.1.1/30 vs 10.1.1.5/30)\n- IP_DRIFT: Lo0 (1.1.1.1/32 vs 2.2.2.2/32)\n\nServiceNow incidents created for all CRITICAL and HIGH findings.\nMarkmap drift summary generated.\n\nOverall: CRITICAL - immediate human review required."}'

Display the audit trail:

python3 $MCP_CALL "python3 -u $GAIT_MCP_SCRIPT" gait_show '{"commit":"HEAD"}'

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Fleet-Wide Reconciliation

To reconcile all devices, first list the inventory:

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_list_devices '{}'

Then query NetBox for all active devices:

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" netbox_get_objects '{"object_type":"dcim.devices","filters":{"status":"active"},"brief":true}'

Run Steps 1-7 for each device that exists in both the pyATS testbed and NetBox. Produce a fleet summary:

Fleet Reconciliation Summary - YYYY-MM-DD
Devices Reconciled: 5/5

+---------+----------+------+--------+-----+----------+
| Device  | CRITICAL | HIGH | MEDIUM | LOW | Overall  |
+---------+----------+------+--------+-----+----------+
| R1      | 2        | 2    | 2      | 1   | CRITICAL |
| R2      | 0        | 1    | 0      | 0   | HIGH     |
| SW1     | 0        | 0    | 3      | 2   | MEDIUM   |
| SW2     | 0        | 0    | 0      | 1   | LOW      |
| FW1     | 0        | 0    | 0      | 0   | CLEAN    |
+---------+----------+------+--------+-----+----------+

Total Discrepancies: 2 CRITICAL | 3 HIGH | 5 MEDIUM | 4 LOW
ServiceNow Incidents Created: 5 (2 CRITICAL + 3 HIGH)
Overall Fleet Status: CRITICAL

Sort devices by severity (CRITICAL first) for triage prioritization.

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NetBox Changelog Audit

After reconciliation, check NetBox changelogs to understand when the source of truth was last updated:

python3 $MCP_CALL "python3 -u $NETBOX_MCP_SCRIPT" netbox_get_changelogs '{"filters":{"object_type":"dcim.interface","limit":20}}'

This helps determine whether discrepancies are due to recent device changes (device drifted) or stale NetBox data (NetBox was never updated).

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Integration with Other Skills

Skill	Integration Point
pyats-topology	Provides CDP/LLDP neighbor data used for UNDOCUMENTED_LINK and CABLE_MISMATCH detection
pyats-health-check	Run health check first; reconciliation adds NetBox cross-reference layer
servicenow-change-workflow	CRITICAL and HIGH discrepancies auto-open ServiceNow incidents
markmap-viz	Drift summary mind map for visual human review
drawio-diagram	Color-code topology links by reconciliation status (green=match, red=mismatch, yellow=undocumented)
GAIT	Full reconciliation session recorded in audit trail

When to Use

• Scheduled: Weekly or monthly source-of-truth validation
• Post-change: After every configuration change, verify NetBox still matches reality
• Incident response: When investigating an outage, check if NetBox data is accurate for the affected devices
• New device onboarding: Verify NetBox was populated correctly after adding a new device
• Audit/compliance: Demonstrate that infrastructure documentation matches reality