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Q
What is a Cisco SFP GLC module?
A
A Cisco SFP GLC module is a small form-factor pluggable transceiver that provides 1 Gbps connectivity over multimode or single-mode fiber for Cisco switches and routers.
Q
How do I install a Cisco SFP GLC module?
A
Power down the switch or router, align the module’s keyed edge with the slot, insert until it clicks, and then power up the device. The module auto-negotiates link parameters.
Q
Which fiber types are supported by Cisco SFP GLC modules?
A
Cisco SFP GLC modules support OM1–OM4 multimode fiber for short-reach (SX) and single-mode fiber for long-reach (LX, LH) applications.
Q
What distances can Cisco SFP GLC modules achieve?
A
Depending on the model, Cisco SFP GLC modules support up to 550 m on OM4 multimode fiber and up to 10 km (LX) or 70 km (LH) on single-mode fiber.
Q
Are Cisco SFP GLC modules hot-swappable?
A
Yes. Cisco SFP GLC modules are hot-swappable, allowing you to add or replace transceivers without powering down the switch or router.
Q
How do I verify Cisco SFP GLC module compatibility?
A
Check Cisco’s hardware installation guide or the transceiver compatibility matrix to confirm support for your switch or router model and software release.
Q
Can I mix multimode and single-mode Cisco SFP GLC modules in one chassis?
A
Yes. You can mix multimode (SX) and single-mode (LX/LH) GLC modules in the same chassis, but each link must match fiber type at both ends.
Q
How do I troubleshoot a non-operational Cisco SFP GLC module?
A
Verify fiber cleanliness, check cable polarity, confirm module compatibility, review interface status commands, and inspect for physical damage.
Q
What is the typical power consumption of a Cisco SFP GLC module?
A
Cisco SFP GLC modules consume approximately 0.8 W to 1 W of power, depending on the specific model and operating conditions.
Q
How do I check the firmware version on a Cisco SFP GLC module?
A
Use the command show interfaces transceiver detail on your Cisco device CLI to display module type, serial number and firmware revision.
Q
Can third-party SFP modules work in Cisco equipment?
A
Cisco only supports Cisco-branded transceivers. Third-party modules may function but can trigger unsupported-transceiver errors and lack official support.
Q
What diagnostics are available on Cisco SFP GLC modules?
A
Cisco SFP GLC modules offer digital optical monitoring (DOM) that reports real-time transmit/receive power, temperature, voltage and bias current.
Q
How do I clean Cisco SFP GLC module fiber connectors?
A
Use dry lint-free wipes or approved fiber cleaning tools and isopropyl alcohol to gently clean endfaces. Always inspect with a fiber microscope.
Q
What are the key benefits of using Cisco SFP GLC modules?
A
Key benefits include hot-swappability, low power consumption, broad compatibility across Cisco platforms and support for a range of fiber distances.
Q
How can I extend reach beyond 10 km with Cisco SFP modules?
A
Use Cisco SFP-ZX modules or X2-10GB-LX4 optics for distances up to 80 km, or deploy DWDM/OTN solutions for even longer spans.
Q
Do Cisco SFP GLC modules support wavelength-division multiplexing (WDM)?
A
Standard GLC modules do not support WDM. For WDM, use Cisco CWDM or DWDM SFP transceivers specifically designed for multiplexed wavelengths.
Q
How do I update the Cisco IOS to support new SFP GLC modules?
A
Review Cisco’s release notes for SFP support, download the recommended IOS image, upload it to your device via TFTP/FTP, and reload the device.
