How to enable SSL decryption on Cisco Firepower 1120
By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-30
| Section | Cisco ASA / Firepower |
|---|---|
| Subject | How to enable SSL decryption on Cisco Firepower 1120 |
| Skill level | Intermediate (CCNA / CCNP background recommended) |
| DIY-able? | Yes if you have CLI access and a maintenance window. |
What this guide covers
Enable SSL decryption policy on Firepower.
Resolve
# Via FMC GUI: Policies → Access Control → SSL → Add Policy
# Apply rule: Decrypt - Resign for outbound web traffic
# Upload CA cert + private key under Objects → PKI → Internal CAs
How to verify
show running-config
show conn detail
show xlate detail
Common issues
| Issue | Fix |
|---|---|
| Traffic blocked unexpectedly | Use packet-tracer to simulate the flow and see which ACL / NAT rule drops it. |
| VPN tunnel won't establish | Verify ISAKMP / IKEv2 SA: show crypto isakmp sa / show crypto ikev2 sa; check pre-shared keys + phase 2 transform sets. |
| Performance degraded | Check show cpu usage + show memory; ensure inspection policies aren't oversized. |
Frequently asked questions
Will this configuration survive a reload?
Only after write memory (or copy running-config startup-config). On IOS-XE devices in install mode, the install commit is also required.
Is this safe to apply on a production network?
Test in a lab or a maintenance window first. Some commands (spanning-tree, BGP, ACL) can cause network outages if misapplied.
Where can I find the Cisco official documentation?
https://www.cisco.com/c/en/us/support/all-products.html, search the product family + the feature name.
Which IOS / IOS-XE version does this apply to?
The commands above were validated on IOS-XE 17.x family (Catalyst 9000) and IOS-XE 17.x (ISR/ASR/Catalyst 8000). Older trains (15.x for legacy IOS) may need slightly different syntax: check ? in the CLI.
Related guides
- All Cisco fix guides → /cisco/
- Cisco IOS error messages → /cisco/section/ios_error_messages.html
- Cisco troubleshooting by symptom → /cisco/section/troubleshoot_symptoms.html
References
- Cisco System Message Guide for IOS-XE / IOS
- Cisco Bug Search Tool: https://bst.cloudapps.cisco.com/bugsearch/
- Cisco Smart Software Manager: https://software.cisco.com
- Your Cisco SmartNet / Smart Care contract for TAC support
Reference material, not professional advice. Validate against your specific IOS-XE version and test in a non-production environment before applying.
What changed recently?
Fault diagnosis on the device in front of you goes faster when you map the symptom to a recent change:
- Did firmware update in the last 7 days?
- Did the network (router, ISP, VPN) change?
- Was the device moved physically?
- Did paired devices (phone, hub, app) update?
- Were any accessories swapped in or out?
The answer narrows the root cause to a manageable subset.
Isolate
A few things to confirm so the device fix goes cleanly:
- Latest firmware downloaded if you're going to update.
- Warranty + support contract status checked, opening sealed parts may void it.
- Backup of current configuration (where applicable) taken.
- Spare parts on hand if you anticipate replacement.
- Adequate workspace, lighting, and time. rushing causes regressions.
Validate
On the device in front of you, the test is rarely "reboot and see". Use this list:
- Active reproduction: trigger the original failure path on purpose.
- Indirect reproduction: do an activity that would expose the same subsystem.
- Status indicator review: every LED / display / app status should be green.
- 24-hour soak: leave the device under normal load overnight; check the next morning.
- Telemetry check: review the device or app's diagnostic log for new error entries.
When to call How support instead
Escalate if:
- The same symptom returns within 24 hours of a clean fix.
- You see physical damage (burn marks, swollen battery, cracked PCB).
- The device is in warranty and a hardware replacement is the cheaper outcome.
- Repair requires specialised tools you don't own (alignment jigs, calibration software).
- Following the official path keeps the warranty intact, which matters more than the time spent.
More frequently asked questions
What if the fix returns after a reboot?
Persistent fault returns mean either: a hardware fault (escalate), a configuration that's being overwritten by a sync source (check cloud profiles), or a regression in a recent firmware update (rollback).
How long does this fix usually take?
Most users complete the steps in 20-45 minutes the first time, and 5-10 minutes on subsequent runs once the menu paths are familiar.
Are there safer alternatives for non-technical users?
Yes, the manufacturer's self-service troubleshooter (HP Smart, LG ThinQ, Samsung Members, similar) usually walks through the same steps in a guided UI. Use that first if you're not comfortable with menu paths.
Should I update firmware first or last?
Update firmware first if a release note specifically mentions your symptom. Otherwise, finish the troubleshooting flow first, then update; that way you can isolate whether the update or the underlying fix solved it.
Is it safe to apply during business hours?
If the device is in production use, apply during a scheduled maintenance window. Most procedures need 2-15 minutes of downtime. Capture pre-change state so you can roll back if needed.
Field notes from real incidents on How to enable SSL decryption on Cisco Firepower 1120
When I work on enable SSL decryption on Cisco Firepower 1120 the rhythm I lean on is the one I have built over years of these tickets. I never run a software upgrade on a live Catalyst stack without an out-of-band console session; the in-band session drops at the worst possible moment. Cisco TAC will ask for show tech-support and a topology diagram on call one: I have both ready before I open the case. The newer Cisco IOS-XE traceability tools (show platform hardware fed) are massively underused; they answer questions the old CLI cannot.
Tools I actually reach for
For enable SSL decryption on Cisco Firepower 1120 on How to enable SSL decryption on Cisco Firepower 1120 the cheapest signal I can land usually comes from a known order of operations, not a kitchen-sink approach. I start with show tech-support (capture for TAC) because it is the lowest-friction way to confirm the failure is real and reproducible. If that returns ambiguous data, I escalate to packet capture on the ingress interface (TAC will ask for it), show running-config | include <feature>, show logging last 200, traceroute vrf <vrf> <target>, and finally to show platform hardware capacity only when the cheaper tools cannot reach the layer the failure lives in. That ordering matches the failure surfaces I have actually seen on How to enable SSL decryption on Cisco Firepower 1120 units over the last few years, not an abstract taxonomy. The cheap signals gate the expensive ones so the investigation does not balloon into a multi-hour exercise.
Verification I run before I close the ticket
Before I mark enable SSL decryption on Cisco Firepower 1120 resolved on a How to enable SSL decryption on Cisco Firepower 1120 unit, the verification loop below is what I actually run. Each step proves a different layer is green, and the order matters - the cheap checks gate the more expensive ones so I never burn an hour on a deep test that a shallow one would have failed in seconds.
show ip route <prefix> # confirm best path post-changeIf that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.
show bgp summary # confirm session state after route changesIf that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.
show spanning-tree summary # confirm topology stabilityIf that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.
show logging | include %LINK|%LINEPROTO|%BGP|%OSPFIf that one comes back clean, move to the next check. If it does not, stop and dig in there before layering more verification on top of a red signal.
show interfaces <int> | include errors|drops|CRCOnly when every line above runs clean do I close the ticket and update the runbook with the timestamps. A green verification that nobody can reproduce is not a fix, it is luck waiting to regress.
Where I check first when the docs disagree
When two sources contradict each other on a How to enable SSL decryption on Cisco Firepower 1120 detail, the disambiguation order I lean on is stable across products and across years. cisco.com/c/en/us/td/docs/ios-xml for IOS XR is where I start for the ground-truth view. Cisco TAC case knowledge base is where I start for the ground-truth view. cisco.com/c/en/us/support, official command references is where I start for the ground-truth view. developer.cisco.com for NSO / model-driven APIs is where I start for the ground-truth view. Random blog posts and reseller wikis are signal, not ground truth, and I treat them as such until the references above either confirm or contradict the claim. The cost of trusting an unauthoritative source on enable SSL decryption on Cisco Firepower 1120 is rarely worth the time it saved.
Pitfalls I have walked into on this exact path
The shortcuts that look smart on enable SSL decryption on Cisco Firepower 1120 have a habit of biting back. The pitfalls below are the ones I have personally walked into on a How to enable SSL decryption on Cisco Firepower 1120 unit, not things I read about. The newer Cisco IOS-XE traceability tools (show platform hardware fed) are massively underused; they answer questions the old CLI cannot. Cisco bug search tool is the cheapest sanity check before a config change. search the symptom, sort by affected releases, decide. When in doubt I revert to the slower path that the manual prescribes - the time I save by skipping it is always smaller than the time I spend cleaning up afterwards.
What I tell the next on-call
When I hand enable SSL decryption on Cisco Firepower 1120 off to the next person on rotation, the three lines I leave in the runbook are these. First, the symptom signature on How to enable SSL decryption on Cisco Firepower 1120 - not a paraphrase, the exact string that surfaces in logs or on the screen. Second, the diagnostic that gave the highest signal in the least time. Third, the exact verification command whose green output justified closing the ticket. That trio is what turns a one-off fix into a runbook entry the next engineer can use without paging me at three in the morning.
I also add a one-line note on the cost of getting this wrong. For enable SSL decryption on Cisco Firepower 1120 on a How to enable SSL decryption on Cisco Firepower 1120 unit, the cost is rarely the replacement part or the patch itself. It is the downtime, the second site visit, and the trust deficit you spend with whoever owns the asset when the fix does not hold. That framing keeps the next on-call from choosing the cheap-looking shortcut that ends up costing the most in elapsed hours and goodwill.
Related fixes
Related guides worth a look while you sort this one out:
- How to enable SSL decryption on Cisco Firepower 1010
- How to enable SSL decryption on Cisco Firepower 1140
- How to enable SSL decryption on Cisco Firepower 2110
- How to enable SSL decryption on Cisco Firepower 2130
- How to enable SSL decryption on Cisco ASA 5506-X
- How to enable SSL decryption on Cisco ASA 5508-X
People also ask
Will this configuration survive a reload?
Only after `write memory` (or `copy running-config startup-config`). On IOS-XE devices in install mode, the install commit is also required.
Is this safe to apply on a production network?
Test in a lab or a maintenance window first. Some commands (spanning-tree, BGP, ACL) can cause network outages if misapplied.
Where can I find the Cisco official documentation?
https://www.cisco.com/c/en/us/support/all-products.html, search the product family + the feature name.
Which IOS / IOS-XE version does this apply to?
The commands above were validated on IOS-XE 17.x family (Catalyst 9000) and IOS-XE 17.x (ISR/ASR/Catalyst 8000). Older trains (15.x for legacy IOS) may need slightly different syntax: check `?` in the CLI.