C9800-L-F-K9 - Cisco Catalyst 9800-L Series WLAN Controller

C9800-L-F-K9: fiber-uplink and optic qualification

C9800-L-F-K9 is the fiber-uplink member of the Catalyst 9800-L family. Cisco identifies four 2.5/1-Gigabit ports and two 10/1-Gigabit optical uplinks. The F PID must remain visible through quotation and receiving because its optic, fiber-plant and distance decisions differ from the copper C model.

Optic and fiber-path qualification

Choose each supported SFP or SFP+ against wavelength, reach, connector, fiber type and the peer interface. Record optic PID and serial, transmit and receive levels, patch-panel path, polarity and negotiated speed. An unsupported or mismatched module can leave the port down even when the controller itself is healthy.

Redundancy validation

Map the two optical uplinks to independent failure domains where the design requires resilience. Preserve spanning, routing or port-channel configuration and test the loss of each path. Store optical diagnostics before and after failover so degradation is not mistaken for an IOS XE or wireless-control fault.

Scale and software evidence

The published base platform supports 250 access points, 5,000 clients and 5 Gbps; the Performance license raises those limits to 500 access points, 10,000 clients and 10 Gbps. Retain Smart Account ownership, license state, IOS XE release and compatibility evidence with the controller backup.

C9800-L-F-K9 receiving record

Verify the full F PID, 4.01-lb published chassis weight, 110W adapter, rack parts, four access-side links and both populated optical ports. Cisco publishes 84.5W maximum consumption assuming two 2.5W SFPs and the stated USB load; use the real optics when completing the power and thermal review.

Official evidence: Cisco Catalyst 9800-L data sheet; Cisco 9800-L deployment guide; and Cisco IOS XE controller release notes.

Related platform comparison

C9800-L-C-K9 copper-uplink controller uses the other uplink medium; compare the distribution design before substitution.