Last Updated on April 9, 2017 by Dave Farquhar
I set up a DD-WRT router on Charter’s Spectrum broadband, and had a hard time getting it to work. It wouldn’t pull an IP address on the WAN side, or it would pull a 192.168 address rather than a Charter public address.
Here’s what I had to do to fix it.
I suspect, but can’t prove, that Charter wants to encourage people to rent their routers from them, because when I had the router clone a MAC address belonging to a Dell computer, it immediately started pulling a public IP. But at least I found a solution, so if you’re having the problem, you can fix it too.
Here’s how to clone a MAC address in DD-WRT.
- Plug a PC directly into your router’s Ethernet port with an Ethernet cable
- Sign in to your router.
- Click Setup, then click MAC Address Clone
- Click Enable, then click Get Current PC MAC address
- Click Apply Settings, then click Save
Once I did that, the router started pulling a proper IP address and I stopped getting warnings on the connected devices about not having Internet access.
I tried both a D-Link router and an antique Linksys WRT54G (autographed by Charles Babbage!). The D-Link would pull an IP address for a while but wouldn’t maintain it long, but the WRT54G worked. It could be the D-Link was marginal and that was contributing to the problem, so I pressed Babbage’s WRT54G, built before I was born, into temporary duty until I could procure something newer.
If you’re having a similar problem and your router isn’t running DD-WRT, see about cloning a MAC address to get it working. It will be different on other routers, but the same solution is likely to work there as well.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.
When my sister got Charter Internet back in the mid-2000s, we had to clone the MAC address of her PC to the first router she had. Fast forward some years later, circa 2012, I had to reset her router due to both of us forgetting the password to log in. When I set the router back up I did not setup the MAC Address Clone feature, and the router connected and pulled an IP address without issue.
Before my wife and I got married, she had Charter Internet service. When I set up a router for her, I initially had to setup the MAC Address Clone feature on the router to pull an IP. When we began living together some years later we kept Charter as our ISP. During this time I got a new router and upgraded it to DD-WRT. When I set up this new router sometime in 2011, I found that I did not have to configure the MAC Address Clone feature.
It should be noted that we never had Charter’s Spectrum Internet service, only Charter’s standard cable internet service, so maybe Charter dropped MAC Address filtering and has now reinstated it with the new service.
I should also note that with Comcast (my current ISP) that I did not have to enable MAC Address Cloning on my DD-WRT enabled router to pull an IP. However, about a month ago, after initially wiping and upgrading the router to a newer version of DD-WRT I booted the router up and it could not pull an IP. I had to power the router down, wait about five minutes, and then boot the router up before the router would pull an IP.
Thanks for those observations, Tom–it’s helpful. Especially the Comcast observations, as I have no experience with Comcast.