How Many Wireless Routers Can You Connect to a Cable Modem?

By Elizabeth Smith

Connecting additional routers can expand your network.
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When you are setting up a wireless Internet network, the number of computers you can reach is limited by the router specifications and the range of the router. By adding additional routers, it seems, you would be able to extend the network without getting another modem. Before you buy more wireless routers, consider the technical expertise and potential ISP problems.

Purpose of Multiple Routers

For people who live or work in a building that has significant wireless interference or is too big to allow the signal to reach everywhere, multiple routers can increase wireless access. Because the signal tends to get weaker the farther you get from the router, computers on the edge of the network may experience slow speeds and weak signal strengths.

Hardware Limitations

The number of routers you can hook up to a cable modem is, to some extent, limited by the modem itself. Most modems come with a single Ethernet port, meaning that you can hook up only one router through a direct connection. If you have advanced programming skills, you can add an unlimited number of additional routers using a chain of Ethernet cables from the first router to the second to the third, etc. In order to do so, you must adjust the IP addresses and gateway commands for the routers. This method should not be attempted by a novice, as it requires advanced networking knowledge.

Wireless Repeaters and Access Points

One of the most common ways to extend the range of a wireless network is to use a second router as a wireless repeater or an access point. Before you can use a router as a repeater, however, you must install DD-WRT firmware on the router and adjust its internal setup and security settings. To use it as an access point, you must disable DHCP. Once it is set up as a wireless repeater or access point, your second router will receive and reflect the Wi-Fi signal to other parts of your building.

ISP Considerations

Although it is possible to use additional routers on a single cable modem, your Internet service provider (ISP) may have regulations prohibiting or limiting the practice. To avoid any issues with your ISP, it is best to check with a representative first. Some service plans and modems have limitations; in addition, adding more routers to a modem will increase your traffic, which may cause your ISP to slow overall service.