Cisco C3850-NM-4-1G Catalyst 3850 Network Module – 4 x 1G SFP Uplink Ports

Upgrade Catalyst 3850 uplinks without replacing the switch.

The Cisco C3850-NM-4-1G is a field-replaceable uplink network module for Catalyst 3850 switches, providing 4 x 1G SFP. It is used to connect a Catalyst 3850 to a 1G distribution layer over fiber or copper SFP modules, giving network teams a simple way to change uplink speed and media as the network grows.

Why Modular Uplinks Protect Your Switch Investment

Fixed-uplink switches lock you into one uplink speed. When the core moves from 1G to 10G, or a new building needs a fiber link, the only option is often to replace the entire switch, along with its cabling and configuration work.

The C3850-NM-4-1G solves this by placing the uplink ports on a removable module. You choose the uplink type that fits today, then swap or upgrade the module later, while the access ports, PoE and configuration of the Catalyst 3850 stay in place.

Because the module is a genuine Cisco part designed for the Catalyst 3850 uplink slot, it is detected automatically and managed from the same CLI and management tools as the rest of the switch.

4 x 1G SFP

The C3850-NM-4-1G provides 4 x 1G SFP. Each port runs at 1G with standard SFP modules such as 1000BASE-SX, LX or copper 1000BASE-T.

Simple Installation and Upgrades

The module slides into the uplink slot at the front of the switch and can be inserted or removed while the switch is running. This keeps maintenance windows short and lets you stock a spare module instead of a spare switch.

How to Install the Cisco C3850-NM-4-1G

1. Confirm your switch model and software release support the C3850-NM-4-1G (check the Cisco compatibility matrix).
2. Remove the blank cover or existing module from the uplink slot and insert the C3850-NM-4-1G until it seats firmly, then tighten the captive screws.
3. Insert the required SFP modules or cables and connect them to the upstream switch.
4. Verify the module with “show inventory” and “show interfaces status”, then configure the uplinks as trunks or EtherChannel members.