Frequently Asked Question
My Mercusys switch has link lights, but connected computers have no internet. Why?
QUICK ANSWER
An unmanaged switch joins Ethernet devices; it does not replace a router, provide an internet login or normally issue DHCP addresses. Check the upstream router connection and client IP settings.
Applies to: MS105, MS108, MS105G and MS108G used on a home or office router's LAN.
Work through these checks
- Draw the connection path. For a typical routed internet setup, connect a router LAN port to the switch, then computers to other switch ports. Connecting several clients straight to a modem or ONT may not provide separate internet sessions.
- Compare one computer directly on the same router LAN port. If it also fails there, investigate the router, internet service or client before replacing the switch.
- Check the affected client's IP address, gateway and DNS. A 169.254 IPv4 address usually indicates that a DHCP lease was not obtained. Confirm the router's DHCP service and available lease pool.
- Check for an unintended loop, an extra router or a wall outlet assigned to a different network. Remove only an identified redundant test connection; preserve office network settings and management access.
Confirm the result
A test computer should receive an address from the intended LAN, reach its gateway and then access the internet. Test a second client before reconnecting all equipment.
Before going further: These unmanaged models have no router setup page to configure. Do not factory-reset the office router or change its WAN settings as an initial test.
If you need help
Include these details in your ticket: Switch and router models, a simple cable diagram, redacted IP/gateway/DNS details and the direct-router test result.
Updated 261107