C3850-NM-4-1G Cisco 4 port network module for 3850 series switches.

Cisco C3850-NM-4-1G - 4-Port 1G SFP Network Module

The Cisco C3850-NM-4-1G is a hot-swappable uplink module designed for Cisco Catalyst 3850 Series switches. It offers four 1-Gigabit SFP uplink slots, giving enterprises the flexibility to deploy fiber uplinks for aggregation, distribution, or core connectivity. This module is ideal for organizations that need reliable 1G fiber connectivity today, with the option to upgrade to 10G modules in the future.

🔧 Key Specifications

• Compatibility: Cisco Catalyst 3850 Series switches
• Uplink Ports: 4x 1-Gigabit Ethernet SFP slots
• Flexibility: Supports standard 1G SFP modules (SX, LX, BX, etc.)
• Important Note: Does not support 10G SFP+ modules. If an SFP+ is inserted, it will not operate and the switch will log an error.
• Hot-Swappable: Can be installed or replaced without powering down the switch
• Form Factor: Rear-insertable network module
• Performance: Provides reliable 1G uplinks for stacking, aggregation, or distribution

🧩 Ideal Use Cases

• Connecting Catalyst 3850 access switches to distribution or core layers at 1G speeds
• Providing fiber uplinks for branch offices or smaller campus deployments
• Environments where 1G fiber is sufficient and cost-effective
• Organizations planning gradual migration to higher-speed uplinks (can later swap to 2x10G or 4x10G modules)

⚙️ Licensing & Expansion

• No additional software license required; uplink functionality is hardware-based
• Compatible with Cisco IOS XE features on Catalyst 3850 switches
• Can be swapped with other Catalyst 3850 network modules (e.g., C3850-NM-2-10G, C3850-NM-4-10G) for future upgrades