Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | A2H124-24FX |
| Product Series | SecureStack A2 |
| Downlink Ports | 24 × 100Base-FX (SC, multimode fiber) |
| Uplink Ports | Up to 4 × Gigabit SFP (Mini-GBIC) slots |
| Switching Capacity | 8.8 Gbps |
| Forwarding Rate | 6.5 Mpps |
| MAC Address Table | 8K entries |
| VLAN Support | IEEE 802.1Q, up to 255 VLANs |
| QoS | IEEE 802.1p priority queuing |
| Spanning Tree | STP / RSTP (IEEE 802.1D) |
| Stacking | Up to 8 switches per stack |
| Management | CLI, Web UI (WebView), SNMP, Telnet |
| Security | 802.1X, port security, MAC filtering, ACL |
| Console Port | DB9 serial (9600, 8N1) |
| Power Input | 100–240 VAC, 50/60 Hz |
| Form Factor | Standard 1U rack-mount |
| Cooling | Fanless passive cooling |
| Operating Temperature | 0°C to 50°C (verify with OEM datasheet) |
| Humidity | 5% to 95% RH, non-condensing |
Product Introduction
Most plant-floor Ethernet segments don’t die from bandwidth starvation. They die from EMI riding a copper run that passes three VFDs and a welding station. The A2H124-24FX exists for exactly that scenario: 24 SC fiber ports in a 1U box, giving you galvanic isolation between the control room and the field.This is the all-fiber member of the Enterasys SecureStack A2 family. It delivers 8.8 Gbps of switching capacity, 8K MAC entries, and up to four Gigabit SFP uplinks for backbone connectivity. The fanless design means no bearings to fail in a warm panel room. It stacks up to eight units, so you can consolidate remote I/O fiber drops into a single managed node. One caveat: Enterasys firmware versions must match across a stack, and finding matching images for this legacy platform is no longer trivial. Always verify the firmware revision before deploying a replacement into an existing stack.
Quality SOP & Tech Pitfalls
The Lab Report (SOP)
- Visual & counterfeit check — label, SC port alignment, SFP slot condition, and DB9 console connector integrity verified.
- Live power-on test — 100–240 VAC applied; fanless chassis checked for abnormal heat; system LEDs verified.
- Port verification — fiber link status checked on multiple 100Base-FX ports; SFP slot communication confirmed with a known-good Mini-GBIC.
- Console access test — DB9 console connected at 9600/8N1; CLI boot verified; firmware version logged.
- Anti-static sealing — unit bagged with desiccant, foam-packed, with test readings logged. Photos or video available on request.
The Engineer’s Warning (Pitfalls)
- Firmware mismatch in stacks: SecureStack A2 stacking requires identical firmware images across all members. A mismatched replacement will either refuse to join the stack or force a full stack reboot. I’ve seen a midnight stack upgrade turn into a six-hour outage because nobody checked the image version.
- Wrong SFP type: The uplink slots take Mini-GBIC modules (MT-RJ or LC fiber, RJ45 copper). Not all third-party SFPs are accepted. Bring a known-working Enterasys Mini-GBIC to the swap.
- SC fiber polarity: TX must go to RX. Reversed pairs give you a clean link LED on one end and nothing on the other. Label both ends before you pull the old unit.
Installation & Configuration Guide
30-Minute Swap Procedure
- Pre-Installation ⚠️
- Notify network operations and identify which fiber segments depend on this switch.
- Photograph the existing unit: port patching, SFP module types, VLAN assignments, and stacking cable connections.
- Record the firmware version from the existing unit’s CLI (
show versionor equivalent).
- Removal
- Label every SC fiber cable by port number.
- Disconnect stacking cables last — note STACK UP vs. STACK DOWN orientation.
- Remove SFP Mini-GBICs and set aside with the replacement unit.
- Unrack the failed unit.
- Installation
- Confirm the replacement reads A2H124-24FX. Not A2H124-24P (copper/PoE) or A4H-series.
- Rack-mount the unit and reinstall the original SFP Mini-GBICs.
- Reconnect stacking cables in the original orientation.
- Patch SC fiber cables per your labels.
- Power-On & Testing
- Apply 100–240 VAC power.
- Connect to the DB9 console port (9600 baud, 8N1, 1 stop bit, no parity).
- Verify firmware version matches the rest of the stack.
- Confirm link status on all 24 fiber ports and 4 SFP uplinks.
- Validate VLAN membership and spanning-tree state before returning traffic.
Compatible Replacement Models
| Compatibility Tier | Model | Notes |
|---|---|---|
| ✅ Drop-in Replacement | A2H124-24FX | Same model, same firmware. No config change needed. |
| ✅ Drop-in Replacement | A2H124-24FX-RH | Functionally identical variant; verify firmware revision before stacking. |
| ⚠️ Software Compatible | A2H124-24P | Same SecureStack A2 chassis, but 24× copper RJ45 ports. Requires port reconfiguration. |
| ⚠️ Software Compatible | A2H124-48P | 48-port copper variant; same firmware family, different port map. |
| ❌ Hardware Mod Required | A4H124-24FX | Different SecureStack generation; not a direct stack mate. Full migration required. |
Frequently Asked Questions (FAQ)
Can I hot-swap this switch in a stack?
Not cleanly. SecureStack A2 stacking is designed for planned expansion, not live replacement. Pulling a stack member will break the stacking ring and may disrupt traffic on the remaining members. Schedule a maintenance window.What’s the difference between A2H124-24FX and A2H124-24P?
Fiber vs. copper. The 24FX gives you 24 SC fiber ports; the 24P gives you 24 RJ45 copper ports (some variants support PoE). Same SecureStack A2 firmware family, but completely different physical layer.Does it support PoE?
No. The A2H124-24FX is a fiber switch. PoE is available on the A2H124-24P and A2H124-48P copper models.What console settings do I need?
DB9 connector, 9600 baud, 8 data bits, no parity, 1 stop bit.How many units can I stack?
Up to 8 SecureStack A2 switches per stack. All members must run the same firmware image.Is this still available new from Enterasys?
The Enterasys brand has changed hands multiple times. Most units in the market today are New Surplus or refurbished. Always confirm the exact model and firmware revision before purchasing.What warranty do you offer?
Standard 12-month warranty on tested units. Pre-shipment test readings — port link status, console access, firmware version — can be provided on request.
