OpenWRT Settings for Cox

For months my OpenWRT-equipped router has been sitting in my closet collecting dust because I couldn’t figure out how to get it to pull an IP from Cox’s DHCP. This then prompted me to bang out a few paragraphs regarding my thoughts on pfSense and OpenWRT. In the very probable case that you aren’t interested in my home networking journey and are more interested in getting your router working here’s the quick and dirty (looking at you, recipe web sites):

Bring up on bootTrue
Hostname to send when requesting DHCP
Use builtin IPv6-managementTrue
Force linkFalse
Use broadcast flagTrue
Use default gatewayTrue
Use DNS servers advertised by peerTrue
Use gateway metric
Client ID to send when requesting DHCP
Vendor Class to send when requesting DHCP
Override MAC address
Override MTU

Values in bold are ones that you probably need to change.

One of the reasons I made this blog was so that I could share these types of technical fixes with the world at large. This was an un-Googlable problem and Cox support is, to put it mildly, ridiculously incompetent about 90% of the time so I’m trying to pay it forward. Shouts out to the seventh support rep that I spoke to a few months back that was finally able to get my internet activated in the first place after ping-ponging back and forth with them for an entire day - your coworkers owe you a beer and Cox owes you a raise.

Why am I running OpenWRT? Seven or so years ago in an effort to expand my networking knowledge I built a modest home lab (okay, so my home network) around a Netgate APU2, an x86-based embedded platform running pfSense with three GbE ports, a serial port, and a spot for a WLAN antenna. To say that it wasn’t the smoothest experience would be an understatement… installation and initial administration required using the aforementioned COM port (in the year 2013! Like it’s an old Cisco router!), the ACL and network semantics were kind of confusing and I was never able to get PCI-E wireless to work. Once everything was configured it ran rock solid, but I didn’t mess with it as much as I should have because I just wanted it to stay working. After decommissioning my home server and facing the eventuality of relocating to an apartment I decided that something simpler would suit my needs better and decided to go the OpenWRT route.

After doing some research I bought a TP-Link AC1750 router with the intent of installing OpenWRT on it. After toiling with it for the better part of a Saturday afternoon I was finally able to get my Fedora machine to talk to the debugger and flash the OpenWRT BIN onto it, and ever since then I’ve been completely satisfied with my router experience. Unfortunately my cross-country move to San Diego meant that I had to switch ISPs and AT&T’s inability to tell me which credit bureau was giving them issues during my credit check meant that I had to use Cox. My AC1750 for some reason wouldn’t pull an IP even after activating my internet service so for the past five months I’ve been using a crappy stock TP-Link travel router that requires a power cycle every few days to avoid randomly dropping 802.11 connections. I decided to revisit the problem today and lo and behold the very first setting that I corrected fixed the problem. Clearly I didn’t try hard enough the first time!


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