Sunday, November 26, 2017

Set up Linksys WRT45GL as router with CenturyLink DSL and C1000A modem

Updated: I installed DD-WRT on my Linksys, so modified instructions below. "Linksys" means stock firmware, "DD-WRT" means DD-WRT firmware. The differences are very minor.

Yet another update: my wife saw a bunch of google stuff at Costco, she bought a set of 3 google home minis and a set of 4 google wifi pucks. So the Linksys is gone.

And one more update: I tried using the Google WiFi as my main house router, and it sucks. Port forwarding simply does not work. Instead, I did what I should have done in the first place -- I set the C1000A in to transparent bridge mode as described below, put my most capable router, a TP-Link Archer C7, as the main router on the 192.168.22.x network (also pretty much as described below), let Google set itself on the 192.168.86.x network (which it insists on doing), and added a route on the C7 so the two networks can talk to each other. Now I have the nice mesh wifi network from Google, all my hard-wired machines can talk to the wifi devices and vice versa, and I have a decent, fully configurable router.


I've been having some trouble with CenturyLink and Private Internet Access VPN, the CenturyLink C1000A can't seem to handle all the connections so the VPN craps out regularly. The reviews of the C1000A are decent as a modem, not so good as a router. I have a Linksys WRT45GL, which has a good reputation as a router, so I've reconfigured my network to just use the C1000A as a modem and the Linksys as the router/gateway. It's pretty straightforward:

Set up the C1000A:

Get username and password for CenturyLink account. If you don't know these (they should have been given to you when you set up the CenturyLink account), you can telnet to the modem and get them as follows:

1. Log into C1000A with your browser.
2. Go to Advanced Setup and then Remote Console (on the left nav) underneath Remote Management. On the Remote Console screen choose the "Telnet Enabled" in the "Select the Console State Below" dropdown menu. Set a username and password, write it down. Click the "Apply" button.
3. Telnet to C1000A. Type "sh" to enter a shell. Type "/usr/bin/pidstat -l -C pppd" and hit Enter. Your username and password will be in the output. The password follows the "-p" in the output. Write these down for future reference. Quit your telnet session.

Note: pidstat is used for monitoring individual tasks currently being managed by the Linux kernel. The "-l" option displays the process command name and all its arguments. The "-C pppd" option filters the output to show only the processes named "pppd".

Log into to C1000A with your browser.

Go to wireless settings. Turn off wifi.

Go to Advanced Settings, then WAN settings, find ISP Protocol and set it to "Transparent Bridge". Click the "Apply" button. Your internet connection will stop working for now.

Set up the Linksys WRT45GL:

Log into Linksys with your browser.

Linksys: Go to Setup, Basic Setup. Set "Internet Connection Type" to PPPoE. Enter your CenturyLink username and password. Set up DHCP if needed on this page since the C1000A will no longer be providing that service.

DD-WRT: Go to Setup, Basic Setup. In "WAN Setup" set "WAN Connection Type" to PPPoE. Enter your CenturyLink username and password. Set up DHCP if needed on this page since the C1000A will no longer be providing that service.

Go to Setup, Advanced Routing. Set "Operating Mode" to Gateway. Save.

Redo the wiring:

Unplug any ethernet cables going to the C1000A, but don't unplug the phone line since that is the DSL connection. Plug those cables into the Linksys. Connect an ethernet cable from the WAN port on the Linksys to one of the ethernet ports on the C1000A.

Restart both boxes:

Unplug C1000A. Unplug Linksys. Wait 1 minute.

Plug in the C1000A. Wait for the connection light to stop blinking (it looks like an outline of an ethernet port). This can take some time, but should be less than 5 minutes.

Plug in the Linksys. Log into it with your browser. Go to the Status page. Check that it's connected and has an IP address.

That is all. Assuming all your devices use DHCP, they should all automatically reconnect with the Linksys as the gateway.

No comments: