How to set up a static ip from Comcast on Ubuntu?

ddario asked:

I’m trying to set up a static IP on an Ubuntu machine that is connected to the internet via a Comcast gateway (SMC).
Following their instructions I added this to the /etc/network/interfaces (the static IP is, for example, and gateway is supposed to be

auto eth0
iface eth0 inet static

However, after I restart networking I loose internet access. (and I can’t investigate further as I’m remotely connected.)

Any ideas on what I’m missing?


My answer:

The SMC piece-of-junk that Comcast gives business customers doesn’t actually route your IP addresses into your network. Instead you have to set up 1:1 NAT and have the public IP address mapped to a private (RFC 1918) address on your LAN. Which, of course, means that all the computers on your LAN have to have RFC 1918 addresses.

Log in to the SMC piece-of-junk (defaults: username cusadmin password highspeed) to complete the configuration. You will need to be on site to do this, since the web-based configuration is only accessible from the LAN side.

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