ASA 5516-X (ASA5516-FPWR-K9) to Firepower 1000 Migration

The Cisco ASA 5516-X with FirePOWER Services (PID ASA5516-FPWR-K9) was the flagship desktop model of the ASA 5500-X line: the highest-throughput member of the non-rackmount tier, popular in branch offices, clinics, regional government sites, and remote enterprise locations that needed real next-generation firewalling without a 1U chassis. It shipped on End-of-Sale in 2021, and it now has one date that matters above all others. The Last Day of Support is August 31, 2026. If your network still depends on a 5516-X, the window to plan and budget a clean refresh is closing.

This guide explains exactly what that date means, why the ASA 5516-X is no longer the right platform regardless of whether it still passes traffic, and how to migrate to its successor, the Cisco Secure Firewall 1000 Series, with config parity, license continuity, and a phased cutover that does not take your perimeter down. You can see the full milestone record on the ASA 5516-X end-of-life detail page.

Why August 31, 2026 is a hard deadline, not a suggestion

A firewall that keeps forwarding packets feels safe, which is precisely the trap. The ASA 5516-X reached End of Sale on August 2, 2021, meaning Cisco stopped selling it new. End of Sale starts the support clock; it is not the problem. The problem is Last Day of Support.

After August 31, 2026, three things stop simultaneously. First, Cisco PSIRT no longer produces security fixes for the platform, so any new critical vulnerability in ASA software or the FirePOWER/Snort engine on this hardware stays unpatched forever. A perimeter firewall is the single worst place to run unpatched code. Second, Cisco TAC will not open new support cases, so when something breaks at 2 a.m. there is no escalation path. Third, RMA hardware replacement ends; a failed power supply or a dead unit cannot be swapped under contract, and a 2016-era appliance has aging components and an end-of-life DRAM/SSD population.

What each milestone date means in practice

• End of Sale (Aug 2, 2021): the SKU can no longer be ordered new from Cisco. Already passed.
• End of Software Maintenance (n/a published for this PID): in practice, maintenance releases for the ASA train this hardware runs have wound down; treat current code as the last you will get.
• Last Day of Support / LDoS (Aug 31, 2026): the terminal date. No PSIRT fixes, no TAC cases, no RMA. Everything contractual ends here.
• Practical lead time: optics, term-license provisioning, and federal procurement vehicles add weeks. Plan to have replacement hardware racked and tested well before LDoS, not on it.

The replacement: Cisco Secure Firewall 1000 Series

Cisco's designated successor is the Firepower 1000 Series, sold today as the Cisco Secure Firewall 1000 Series. It is a desktop-class family built around a multi-core x86 platform with hardware crypto acceleration, and it is generationally ahead of the 5516-X in every dimension that matters.

What is concretely better

Throughput. The ASA 5516-X delivered roughly 900 Mbps of stateful firewall throughput and dropped to the low hundreds of Mbps once FirePOWER threat inspection (AVC + NGIPS) was enabled, with around 250,000 maximum connections. The Secure Firewall 1120/1140/1150 deliver multiple gigabits of firewall throughput and 1 to 2+ Gbps of threat inspection with all features on, plus an order-of-magnitude higher connection capacity. For a branch that has grown from 100 Mbps to a gigabit WAN since 2016, this is the difference between a bottleneck and headroom.

Unified software. The 5516-X ran two worlds bolted together: classic ASA for stateful firewall and VPN, and a separate FirePOWER Services module for NGIPS and AMP, managed and updated independently. The Secure Firewall 1000 runs Secure Firewall Threat Defense (FTD), a single image that fuses the ASA data plane with the Snort 3 inspection engine. One policy model, one upgrade, one management plane.

Management. Choose on-box Secure Firewall Device Manager (FDM) for single-site simplicity, Secure Firewall Management Center (FMC, virtual or appliance) for centralized multi-site policy, or cloud-delivered FMC for SaaS management with no on-prem controller to maintain. The 5516-X's FireSIGHT/FMC-only model for the NGFW features was far less flexible.

Interfaces and crypto. The 1100 models offer multiple Gigabit copper ports plus SFP/SFP+ uplinks (the 1150 adds 10G SFP+), giving you fiber or 10G options the 5516-X's all-copper face never had. AES-GCM and modern VPN ciphers are hardware-accelerated, so site-to-site and RAVPN tunnels run faster while leaving CPU for inspection.

A practical migration plan

1. Assess and inventory

Capture the current 5516-X running-config, the FirePOWER access-control policy, IPS policy, and any AMP/URL settings. Record real throughput and peak connection counts, interface assignments, VLAN/sub-interfaces, NAT rules, VPN peers and crypto maps, and HA pairing. This inventory drives both sizing (1120 vs 1140 vs 1150) and the parity checklist.

2. Size and order the right model

Match sustained threat-inspection throughput to your WAN plus internal inspection needs, not just the firewall headline number. A single-WAN branch is usually well served by a 1120 or 1140; sites needing 10G fiber uplinks or higher VPN concurrency move to the 1150. Browse and compare the family on our catalog, or request a sized quote so the PID and licenses match your traffic.

3. Convert configuration and reach feature parity

Use the Cisco Firepower Migration Tool. Pointed at your ASA config (and optionally the FirePOWER policy), it converts interfaces, objects, ACLs, and NAT into an FTD policy you review and tune. Plan to manually re-validate VPN (especially identity certificates and DH groups), dynamic routing, and any ASA features that map differently in FTD. Decide deliberately between ASA mode and FTD; for nearly all NGFW deployments, FTD is the right destination.

4. Handle the physical and licensing details

• Power and space: both are desktop/1U-friendly; confirm the new unit's PSU and any rack ears if you are mounting it.
• Uplinks and optics: if you move to SFP/SFP+, order Cisco-coded transceivers and the right fiber; the 5516-X's copper-only ports will not carry over.
• HA: rebuild the high-availability pair on the new platform; FTD HA config differs from ASA failover.
• Smart Licensing: register both units to the Smart Account and confirm Threat/Malware/URL term subscriptions are attached before cutover.

5. Phased cutover

Stage and burn-in the new appliance offline, then run it in parallel where possible (out-of-band management, test SVIs, or a maintenance-window pilot). Cut over interface-by-interface or as a scheduled swing with the old unit on standby for rapid rollback. Validate NAT, VPN tunnels re-establishing, and inspection logging in FMC/FDM before you decommission anything.

6. Secure decommission

Once the new firewall is steady, wipe the 5516-X: erase the ASA config and any stored secrets/certs, and securely sanitize the FirePOWER SSD before the hardware leaves your control. For federal and healthcare environments, follow your media-sanitization standard (e.g., NIST 800-88) and keep a disposal record.

Procurement notes for government and enterprise

TAA compliance: confirm the exact Secure Firewall 1000 PID on your quote is a TAA-compliant configuration for federal/DoD/SLED acquisition. Payment and vehicles: the platform supports GPC/credit-card purchases for smaller buys and standard contract vehicles for larger ones. Lead times: term-license provisioning and optics can add weeks, and federal cycles add more, so order with margin against the August 31, 2026 LDoS. Sourcing: buy from an authorized Cisco partner to guarantee genuine hardware, valid Smart Licensing entitlements, and warranty/support eligibility. See related timelines on our EoL hub.