Sourced for enterprise IT teams, the HP J4859AR (J4859AR - HP ProCurve X121 1.25Gb/s 1000Base-LX SFP 1310nm 10km Multimode DOM Duplex LC SFP Transceiver Module) is a Transceiver component appropriate for new-build, expansion, or warranty-replacement procurement. Technical specifications include capacity of 1.25 GB, data rate of 25 Gb/s, wavelength of 1310 nm, range of 10 km. Appropriate for enterprise core-aggregation tier, hyperscale leaf-spine fabric expansion, EVE-NG / GNS3 lab environments at scale, and matched-pair high-availability switching deployments. Pro Disk Network sources the J4859AR through reputable distribution channels and applies a verification check against the OEM compatibility matrix before each unit is added to active inventory. Each unit ships from a US fulfillment hub (Hillsboro OR, Atlanta GA, or Phoenix AZ) with same-day dispatch on in-stock orders before 3pm ET. 90-day Pro Disk Network functional warranty included; free US ground shipping on orders over $150.
The J4859AR is a HP transceiver component with capacity 1.25 GB, data rate 25 Gb/s, wavelength 1310 nm. Pro Disk Network sells the J4859AR for $191.58 with same-day US shipping and a 30-day return guarantee.
Reviewed By
Reviewed by:Pro Disk Network Engineering Team — . Specifications, compatibility, and pricing for the J4859AR are shown on this page.
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Same-Day US Shipping — orders before 3pm ET ship today via UPS
30-Day Returns — pre-paid label on DOA and defective items
Quick Answer: Is the J4859AR compatible with my switch?
Pro Disk Network validates every J4859AR against the target switch's published compatibility matrix before shipment. If you let us know your switch model and firmware version, we will confirm fitment and code the module appropriately (Cisco-coded, Juniper-coded, HPE-coded, etc.) at no extra charge.
How fast does the J4859AR ship?
Pro Disk Network dispatches the J4859AR same-day on orders confirmed before 3 pm ET. Multi-pallet projects requiring crating ship within 2 business days. International shipping (Canada, Mexico, EU, APAC) takes 3-7 business days via DHL Express or FedEx International Priority.
The J4859AR is deployed by US enterprises, MSPs, government, and education customers across multiple infrastructure scenarios. Below are the most common deployment patterns Pro Disk Network sees in real-world orders.
DCI (Data Center Interconnect) — Inter-DC routing or aggregation. LR4/LR8 transceivers for 10–80 km, ER4 for 40 km, ZR4 for coherent long-haul.
Campus Distribution — Catalyst-class campus distribution between IDF and MDF closets. PoE+ where wireless APs and IP phones share infrastructure.
Branch / Edge — Smaller form-factor switches and routers for branch sites. SD-WAN-compatible or static-VPN-attached as the architecture dictates.
What is the J4859AR?
The J4859AR is a HP network interface module with capacity 1.25 GB and data rate 25 Gb/s, manufactured by HP. Pro Disk Network ships this part new and certified-refurbished from our US warehouse with same-day dispatch on orders placed before 3 PM ET, backed by a 30-day return guarantee.
Pros & Cons of J4859AR
Pros
Same-day US shipping cuts deployment downtime
Cons
DAC cables capped at 7 m — use AOC or fibre for longer runs
SR optic vs LR optic confusion — verify before ordering
Refurbished tier optic does not include retail vendor packaging
Frequently Asked Questions about J4859AR
Is the J4859AR a genuine HP part?
Yes. Pro Disk Network sources every J4859AR as factory-original HP inventory. New units arrive sealed in OEM packaging; refurbished units are pulled from decommissioned HP servers, surface-tested, and re-warranted by Pro Disk Network for 90 days.
Is the J4859AR compatible with my switch?
Pro Disk Network validates every J4859AR against the target switch's published compatibility matrix before shipment. If you let us know your switch model and firmware version, we will confirm fitment and code the module appropriately (Cisco-coded, Juniper-coded, HPE-coded, etc.) at no extra charge.
How fast does the J4859AR ship?
Pro Disk Network dispatches the J4859AR same-day on orders confirmed before 3 pm ET. Multi-pallet projects requiring crating ship within 2 business days. International shipping (Canada, Mexico, EU, APAC) takes 3-7 business days via DHL Express or FedEx International Priority.
What is the warranty on the J4859AR?
New J4859AR units carry the full HP manufacturer warranty (typically 1 to 5 years depending on product line). Refurbished and bulk-OEM units include a Pro Disk Network advance-replacement warranty (90 days refurbished). DOA replacement is free within 30 days of receipt.
Do you offer bulk pricing for the J4859AR?
Email sales@prodisknetwork.com with the quantity and target ship date for a quote within one business day.
Optic Coding, Vendor Lock-In, and Multi-Vendor Compatibility
If you are running a multi-vendor leaf-spine architecture (Arista leaves and Cisco spines, for example), order optics coded for each endpoint separately. Optics in DAC and AOC cables are factory-coded to each end and cannot be flashed in-field. Plan the coding split at design time and document it in your network drawings.
Bandwidth Sizing for Spine-Leaf, EVPN-VXLAN, and Hyperconverged Storage
Sizing network bandwidth for a leaf-spine fabric using the J4859AR starts with the workload mix. For general-purpose virtualisation, plan 10G server-to-leaf, 25G or 40G leaf-to-spine; oversubscription up to 4:1 is acceptable. For hyperconverged storage (vSAN, Ceph, Storage Spaces Direct), plan 25G server-to-leaf at minimum, 100G leaf-to-spine, oversubscription 1.5:1 maximum. East-west traffic dominates in HCI clusters and starves on oversubscribed fabrics.