Safe ACI policy change deployment - ServiceNow CR lifecycle, pre/post-change fault baselines, APIC policy application, automatic rollback on fault delta, and GAIT audit trail. Use when deploying ACI policy changes, creating tenants or EPGs, pushing config to APIC, or running a change window with rollback protection.
NEVER deploy an ACI policy change without an approved ServiceNow Change Request. If there is no CR, create one first. If the CR is not approved, do not proceed.
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" TOOL_NAME '{"param":"value"}'
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" TOOL_NAME '{"param":"value"}'
Before touching the APIC, create a CR that documents the tenant, VRF, BD, and EPG scope of the change.
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" create_change_request '{"short_description":"ACI: Create tenant prod-web with VRF, BD, and EPG","description":"Create new tenant prod-web in ACI fabric.\n\nScope:\n- Tenant: prod-web\n- VRF: prod-web-vrf (enforced)\n- BD: web-bd (subnet 10.10.1.1/24)\n- App Profile: web-app\n- EPG: web-frontend (VLAN 100)\n\nAPIC: sandboxapicdc.cisco.com\nRisk: Low - net new tenant, no impact to existing policy","type":"normal","risk":"low","impact":"low","category":"Network"}'
Save the returned change_id (sys_id) and number (e.g., CHG0030001) for all subsequent steps.
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" add_change_task '{"change_id":"CHG0030001","short_description":"Pre-change: Capture ACI fault baseline","description":"Record fault counts by severity before applying any changes"}'
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" add_change_task '{"change_id":"CHG0030001","short_description":"Apply: Create tenant/VRF/BD/EPG on APIC","description":"Apply ACI policy objects via APIC REST API"}'
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" add_change_task '{"change_id":"CHG0030001","short_description":"Post-change: Verify zero new faults","description":"Compare fault counts with baseline, verify new objects operational"}'
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" submit_change_for_approval '{"change_id":"CHG0030001","approval_comments":"Low-risk net new tenant creation. No existing policy affected."}'
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" get_change_request_details '{"change_id":"CHG0030001"}'
STOP if the CR state is not "implement" or "approved". Do not proceed with any APIC changes until the CR is approved. If rejected, review the rejection reason:
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" list_change_requests '{"query":"number=CHG0030001","limit":1}'
Capture the current fabric state so you can detect any regression after the change.
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" faults '{}'
Count and record faults by severity:
Pre-Change Fault Baseline
--------------------------
Critical: 0
Major: 2
Minor: 7
Warning: 12
Total: 21
Store these counts -- they are the rollback reference.
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" health '{}'
Record the overall fabric health score (e.g., 97/100).
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" tenants_get '{}'
Confirm the target tenant does not already exist (for create operations) or does exist (for modify operations).
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" update_change_request '{"change_id":"CHG0030001","work_notes":"Pre-change baseline captured:\n- Faults: 0 critical, 2 major, 7 minor, 12 warning (21 total)\n- Health score: 97/100\n- Tenant prod-web does not exist (confirmed)\n\nProceeding with implementation."}'
Apply changes one object at a time, in dependency order: Tenant -> VRF -> BD -> App Profile -> EPG.
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" tenants_post '{"name":"prod-web","descr":"Production web services tenant"}'
Verify the response indicates success before proceeding.
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvCtx_post '{"tenant":"prod-web","name":"prod-web-vrf","descr":"Production web VRF","pcEnfPref":"enforced"}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvBD_post '{"tenant":"prod-web","name":"web-bd","descr":"Web tier bridge domain","vrf":"prod-web-vrf"}'
After creating the BD, configure the subnet (the exact tool depends on your ACI MCP server capabilities -- it may be a separate subnet tool or a parameter on the BD creation).
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvAp_post '{"tenant":"prod-web","name":"web-app","descr":"Web application profile"}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvAEPg_post '{"tenant":"prod-web","ap":"web-app","name":"web-frontend","descr":"Web frontend EPG","bd":"web-bd"}'
After each object creation: Check the APIC response for errors. If any call fails, STOP and do not proceed to the next object.
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" faults '{}'
Compare with Phase 2A baseline:
Post-Change Fault Comparison
------------------------------
Pre Post Delta
Critical: 0 0 0
Major: 2 2 0
Minor: 7 7 0
Warning: 12 12 0
Total: 21 21 0 (no new faults)
Decision matrix:
| Fault Delta | Action |
|---|---|
| No new faults | PASS -- proceed to CR closure |
| New warning/minor only | PASS with note -- document in CR |
| New major faults | INVESTIGATE -- may need rollback |
| New critical faults | ROLLBACK immediately |
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" health '{}'
Flags:
Confirm each object exists and is in the expected state:
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" tenants_get '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvCtx_get '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvBD_get '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvAp_get '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvAEPg_get '{}'
Verify the new tenant, VRF, BD, app profile, and EPG all appear in the returned data with correct attributes.
If the fault count increases or the health score drops significantly, roll back in reverse dependency order: EPG -> App Profile -> BD -> VRF -> Tenant.
Rollback is required when:
After rollback, re-run Phase 4A and 4B to confirm the fabric returned to baseline.
Update the CR with rollback details:
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" update_change_request '{"change_id":"CHG0030001","work_notes":"ROLLBACK PERFORMED: New critical fault detected after EPG creation. All objects removed in reverse order. Fabric returned to baseline (21 faults, health 97/100). Root cause investigation needed.","state":"canceled"}'
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" update_change_request '{"change_id":"CHG0030001","state":"closed","work_notes":"Change completed successfully.\n\nPost-change verification:\n- Fault delta: 0 new faults\n- Health score: 97/100 (unchanged)\n- All objects verified operational:\n - Tenant: prod-web\n - VRF: prod-web-vrf (enforced)\n - BD: web-bd\n - App Profile: web-app\n - EPG: web-frontend\n\nChange implementation complete."}'
If rollback was needed or issues were found:
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" update_change_request '{"change_id":"CHG0030001","work_notes":"Change failed: fault delta detected. Rollback completed. Escalating for root cause analysis.","state":"canceled"}'
Record the complete change session in GAIT for compliance:
python3 $MCP_CALL "python3 -u $GAIT_MCP_SCRIPT" gait_record_turn '{"input":{"role":"assistant","content":"ACI change deployment completed.\n\nCR: CHG0030001 - Create tenant prod-web\nAPIC: sandboxapicdc.cisco.com\nResult: SUCCESS\n\nObjects created: tenant prod-web, VRF prod-web-vrf, BD web-bd, AP web-app, EPG web-frontend\nPre-change faults: 21 (0 critical)\nPost-change faults: 21 (0 critical) - delta: 0\nHealth score: 97/100 (unchanged)\nRollback required: No\nCR Status: Closed","artifacts":[]}}'
This example walks through creating tenant "prod-web" with a VRF, bridge domain, application profile, and EPG:
# Step 1: Create ServiceNow CR
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" create_change_request '{"short_description":"ACI: Create tenant prod-web with VRF/BD/EPG","type":"normal","risk":"low","impact":"low","category":"Network","description":"Net new tenant for web services. Scope: tenant prod-web, VRF prod-web-vrf, BD web-bd (10.10.1.0/24), AP web-app, EPG web-frontend."}'
# Step 2: Submit CR for approval
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" submit_change_for_approval '{"change_id":"<sys_id_from_step_1>","approval_comments":"Low risk, net new tenant."}'
# Step 3: Verify CR approved (MUST pass before continuing)
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" get_change_request_details '{"change_id":"<sys_id_from_step_1>"}'
# Step 4: Capture pre-change baselines
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" faults '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" health '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" tenants_get '{}'
# Step 5: Apply changes (dependency order)
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" tenants_post '{"name":"prod-web","descr":"Production web services"}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvCtx_post '{"tenant":"prod-web","name":"prod-web-vrf","pcEnfPref":"enforced"}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvBD_post '{"tenant":"prod-web","name":"web-bd","vrf":"prod-web-vrf"}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvAp_post '{"tenant":"prod-web","name":"web-app"}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvAEPg_post '{"tenant":"prod-web","ap":"web-app","name":"web-frontend","bd":"web-bd"}'
# Step 6: Post-change verification
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" faults '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" health '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" tenants_get '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvCtx_get '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvBD_get '{}'
APIC_URL=$APIC_URL USERNAME=$ACI_USERNAME PASSWORD=$ACI_PASSWORD python3 $MCP_CALL "python3 -u $ACI_MCP_SCRIPT" fvAEPg_get '{}'
# Step 7: Close CR (if successful)
python3 $MCP_CALL "python3 -u $SERVICENOW_MCP_SCRIPT" update_change_request '{"change_id":"<sys_id_from_step_1>","state":"closed","work_notes":"Change completed. Fault delta: 0. Health unchanged. All objects verified."}'
# Step 8: GAIT audit trail
python3 $MCP_CALL "python3 -u $GAIT_MCP_SCRIPT" gait_record_turn '{"input":{"role":"assistant","content":"ACI change CHG0030001 completed successfully. Tenant prod-web created with VRF/BD/AP/EPG. Zero fault delta. CR closed.","artifacts":[]}}'
After every change, produce a change report:
ACI Change Report
==================
CR: CHG0030001 - Create tenant prod-web
APIC: sandboxapicdc.cisco.com
Timestamp: YYYY-MM-DD HH:MM UTC
Operator: NetClaw AI Agent
Change Scope
-------------
Tenant: prod-web (NEW)
VRF: prod-web-vrf (enforced)
Bridge Domain: web-bd (subnet 10.10.1.1/24)
App Profile: web-app
EPG: web-frontend
Pre-Change State
-----------------
Faults: 0 critical, 2 major, 7 minor, 12 warning (21 total)
Health Score: 97/100
Tenant Count: 5
Post-Change State
------------------
Faults: 0 critical, 2 major, 7 minor, 12 warning (21 total)
Health Score: 97/100
Tenant Count: 6 (+1 prod-web)
Fault Delta: 0 new faults
Verification: PASSED -- all objects operational
Rollback: Not required
CR Status: Closed