Switching platforms
What belongs in a Catalyst 9400 C9400-LC-48XS expansion BOM?
Supervisor choice changes the slot bandwidth behind forty-eight optical ports.
A line-card quotation can be correct at the SKU level and incomplete as a system. The missing supervisor or slot assumption can change the capacity the buyer actually receives.
The short answer
Treat C9400-LC-48XS as an expansion component. Verify the existing chassis, SUP-2/2XL, software and power configuration, then select optics and calculate usable slot and uplink capacity for the complete system.
A C9400-LC-48XS line card must be planned with its chassis, supervisor capacity, power and optics as one system. Conceptual illustration; equipment shapes are illustrative.
Official technical sources · Independent analysis by SwitchInfra
This is a documented design analysis, not a customer deployment claim. Candidate roles require verification for your configuration.
48 — 1G/10G optical ports
240 Gbps — slot bandwidth with SUP-2
480 Gbps — slot bandwidth with SUP-2XL
17.8.1 — documented minimum IOS XE
What the technical reference establishes
Cisco’s installation note limits this card to C9400X-SUP-2 and SUP-2XL and specifies a minimum IOS XE release. The line-card data sheet distinguishes their per-slot bandwidth.
The useful ordering decision is therefore whether the proposed card expands an already suitable system or triggers a wider chassis upgrade. Establish that boundary before comparing the price of the line card with a complete fixed switch.
Cisco Catalyst 9400 line-card installation note
Component — The 48XS is a line card, not a standalone switch.
Supervisor — SUP-1 variants are not compatible with this card.
Bandwidth — SUP-2 and SUP-2XL provide different slot capacity.
Optics — Transceivers and peer compatibility remain separate selections.
Scope of the analysis: Independent engineering analysis of official documentation. The design exercises are illustrative; this guide does not describe a customer deployment.
Work through the engineering choices
Start with the documented constraint, then state the conditions for the proposed equipment role.
Audit the chassis that will receive the card
The installation note identifies supervisor compatibility and software requirements.
Design exercise: Design exercise: add optical ports to an existing campus aggregation system.
Record the installed chassis, supervisor PIDs, software release, occupied slots, power supplies and planned redundancy mode. Ask for the actual inventory rather than assuming that every Catalyst 9400 generation accepts the same cards. Mark any required supervisor or software change as a separate dependency.
Identify the usable slot and the maintenance plan before preparing a final parts list. A physically empty position is not enough evidence of a complete expansion path. Keep spare quantities, rack power and management requirements visible, especially if the order changes more than one existing subsystem.
Cisco Catalyst 9400 line-card installation note
48-port optical expansion card
Requires a compatible complete Catalyst 9400 system.
C9400X-SUP-2
Compatible supervisor option
Review the documented 240 Gbps per-slot bandwidth for this card.
C9400X-SUP-2XL
Compatible supervisor option
Review the documented 480 Gbps per-slot bandwidth and the complete system.
Calculate capacity at the slot and uplink levels
The data sheet specifies 240 or 480 Gbps per slot for this card.
Design exercise: Design exercise: compare SUP-2 and SUP-2XL using the same proposed port population.
Forty-eight ports configured at 10G total 480 Gbps of nominal one-direction edge capacity. Against a 240 Gbps slot allocation, that gives a simple 2:1 comparison; against 480 Gbps, it gives 1:1. Use these as capacity ratios, not measured traffic results or a promise for every application.
Next check where the traffic leaves the chassis. Adequate slot bandwidth cannot eliminate a bottleneck on external uplinks, and local traffic does not necessarily follow the same path as remote traffic. Define the simultaneous workload and the surviving capacity after the agreed failure before deciding that a more expensive supervisor is justified.
Cisco Catalyst 9400 line-card data sheet
Quote the working system and its channels
The card provides SFP/SFP+ interfaces rather than a fixed optical PMD.
Design exercise: Design exercise: prepare an expansion quotation that another engineer can review.
Group the BOM into reused equipment, required new system components, per-link optics, patching and spares. Keep the peer optic on each link in the same review. A single-mode channel and a multimode channel may both present LC but require different optical choices.
Specify the desired supported software release rather than treating the historical minimum as a deployment recommendation. Confirm software entitlements, support eligibility and offered-unit condition in the commercial response. The deliverable should make clear which existing items the quotation depends on, so installation is not blocked by an unstated assumption.
Cisco Catalyst 9400 line-card installation note · Cisco optics compatibility matrix
SFP-10G-LR
Conditional single-mode port optic
A separate channel and compatibility decision for each endpoint pair.
An expansion RFQ starts with the installed inventory
Attach a populated chassis schedule and show what will be reused.
Cisco Catalyst 9400 line-card installation note · Cisco Catalyst 9400 line-card data sheet
System
Chassis, supervisors, software, slot and PSU/fan inventory.
Capacity
Port population, per-slot bandwidth, uplinks and failure-state requirement.
Links
Both endpoints, optics, fiber channels, quantities and spares.
Candidate models and selection boundaries
These are conditional model or product-family inquiries for the documented equipment roles. Confirm the required rate and complete channel before finalizing any line.
| Model / family and status | Role and condition |
|---|---|
| C9400-LC-48XS Conditional listed line card | 48-port optical expansion card Requires a compatible complete Catalyst 9400 system. Cisco Catalyst 9400 line-card installation note |
| C9400X-SUP-2 Conditional model inquiry | Compatible supervisor option Review the documented 240 Gbps per-slot bandwidth for this card. Cisco Catalyst 9400 line-card data sheet |
| C9400X-SUP-2XL Conditional model inquiry | Compatible supervisor option Review the documented 480 Gbps per-slot bandwidth and the complete system. Cisco Catalyst 9400 line-card data sheet |
| SFP-10G-LR Conditional model inquiry | Conditional single-mode port optic A separate channel and compatibility decision for each endpoint pair. Cisco optics compatibility matrix |
C9400-LC-48XS is verified as catalog product 7520, on request. Targeted supervisor queries returned no exact supervisor listing; SUP-2/2XL remain model inquiries. No complete system or optical compatibility bundle is established.
Continue in the relevant product family
Use the analysis to define the role before comparing catalog options.
Network Modules and Line Cards
Discuss this project
Carry the route, media, endpoint and loss requirements into the inquiry. Leave unknown quantities blank; reference port and fiber counts are not an equipment BOM.
Follow the next selection question.
Compare related decisions while keeping each source’s scope, hardware and link conditions separate.
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ACI selection: turn the diagram into a port budget
Count fabric and server interfaces separately before selecting optical channels.
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Campus versus server access: read both port rows
Endpoint rate and shared uplink capacity require different checks.
Read the engineering analysisOfficial technical source
Nexus 3172 reuse: check the remaining horizon
Review copper access, the separate optical uplink and the actual support scope.
Read the engineering analysisOfficial technical source
Before you finalize the channel
Can the 48XS operate by itself?
No. It is a component of a compatible Catalyst 9400 system.
Does any Catalyst 9400 supervisor support it?
No. The cited compatibility table specifies SUP-2 and SUP-2XL.
Do 48 × 10G ports guarantee 480 Gbps through every configuration?
No. The selected supervisor’s per-slot bandwidth matters.
Should the minimum software release be the target release?
Not automatically. Choose a supported release for the actual system and features.
Trace the project facts and technical limits
- Cisco Catalyst 9400 line-card installation note
- Cisco Catalyst 9400 line-card data sheet
- Cisco optics compatibility matrix
Source check: 19 October 2026. Catalog status is stated per candidate.
Official sources checked 19 October 2026. Final host, software, channel and offered-unit compatibility require project-specific verification.