For the past few years, I've had SDSL 768/768 from my ISP. I could run services (e.g., mail server, jabber server, web server, etc) and have a static IP address. It had worked flawlessly. A few weeks ago, my provider mentioned that they now had an ADSL package (3mb/768k) for less money and with all the same advantages (e.g., static IP address and services allowed).

On the surface, the upload speed didn't change, but the download speed was significantly faster. What could it hurt, let's give it a shot, right? Ehhhh!!! For those of you not familiar with PPPoE, it stands for Point-to-Point Over Ethernet. Previously, my connection was direct in that it didn't require PPPoE nor a username/password to connect. Things changed quickly though.

So for me to actually roll over to my new IP address, I had to coordinate a few things such as updating the NS records for my domains, help my friends update their name server records for their domains I host and generally reconfigure all the externally facing services (e.g., ssh, jabber, dns, etc) that I run. In addition, I also had to find the right pair of phone lines running into my apartment since I previously had a pair for the SDSL service. Pain in the butt, nonetheless, that was the easy part.

Queue the PPPoE theme music duh duh duh dooooo. So I managed to find a few small tutorials on actually making PPPoE on Ubuntu Linux work. In fact, after about 30 minutes, I had it working just fine, or so I thought. There are two problems that I faced with the following command:

sudo pppoeconf 

1. The /etc/network/interfaces file this command generates if successful is incorrect.
2. The interfaces aren't always listed in the right order, especially if you have a box with multiple interfaces (4 in this case), but that isn't really mentioned anywhere.

During my initial troubleshooting, the only way I could get connectivity would be to boot the box, bring up the interfaces manually, and then issue the pon dsl-provider command. Although this worked, upon reboot I would have to do it all over again and at this point, it was already cutting into my Monday shows (e.g., 24 and Prison Break)...grrr!

After about an hour of research and about 15 reboots later, I managed to track down two important pieces of information:

1. There was a bug in pppoeconf that would generate a /etc/network/interfaces file that was incorrect.
2. The interfaces are brought up in the order they are listed, so I needed to put my eth0 interface before my ppp0 interface.

Finally, after discovering these key pieces of information, I made some changes to the /etc/network/interfaces file and rebooted the machine. Thankfully, everything came up successfully with no problems. I've included my /etc/network/interfaces file below in case others might run into a similar problem.

dgm@cerberus:~$ cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# This is a list of hotpluggable network interfaces.
# They will be activated automatically by the hotplug subsystem.
mapping hotplug
        script grep
        map eth0
        map eth1
        map eth2
        map eth3

# The loopback interface
auto lo
iface lo inet loopback

# The server network interface
auto eth1
iface eth1 inet static
        address 192.168.1.1
        netmask 255.255.255.248
        network 192.168.1.0
        broadcast 192.168.2.7
        gateway 66.207.132.69

# The wired network interface
auto eth2
iface eth2 inet static
        address 192.168.2.1
        netmask 255.255.255.248
        network 192.168.2.0
        broadcast 192.168.2.7
        gateway 66.207.132.69

# The wireless network interface
auto eth3
iface eth3 inet static
        address 192.168.3.1
        netmask 255.255.255.240
        network 192.168.3.0
        broadcast 192.168.3.15
        gateway 66.207.132.69

# added by pppoeconf
auto eth0
        iface eth0 inet manual
        pre-up /sbin/ifconfig eth0 up # line maintained by pppoeconf

auto dsl-provider
iface dsl-provider inet ppp
provider dsl-provider