CenturyLink DSL Setup on a Cisco 1720

I turned up a 7Mbps DSL connection with CenturyLink this evening. Here’s the configuration I used to get the circuit working. The ‘debug ppp authentication command’ helped a lot, too.

Note: To get the username and password I had to call CenturyLink technical support. The CenturyLink provisioned modems must have some mechanism to get the necessary information automatically.

Layer 2 Protocols on Serial Links

Earlier today I was tasked with getting two serial interfaces to talk with each other. Frame-relay is far from my strong suit, so I question-marked my way through the FR commands, making up DLCIs, adding map statements, etc. After several minutes with no luck I looked at the solution. As it turns out, Frame-relay was entirely unnecessary! And so began my Layer 2 serial interface education.

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