The cable-net connection I am using as a backup link is different from the mass of desi cable networks available across the city. All I have to do to reach out to the byte world is plug in the patch cable, wait for the DHCP client to request a lease, and that’s it. There are no proxy or any otherwise preposterous settings required. Best of it all, almost everything (almost everything because I’ve yet to bump into something that isn’t) is open and available to me. I can surf, download, IM, open remote terminal and shell sessions, download torrents and access P2P networks, etc. The only major drawback is the single patch cable connection which makes difficult sharing the connection among other systems at home. Also, this particular cable-net vendor relies heavily on MAC filtering to maintain law, order, and control, so, for example, when you plug in the patch cable into your laptop at night, you don’t get allowed access to get to the Internet. Apparently, you have to pay an extra one-time fee to associate another MAC address with your connection. For people who hop from one system to another in the course of their day, such as myself, that can be an annoyance. And when there’s annoyance, there is someone bending the rules.
For all Windows lovers out there, Macshift and Mac MakeUp are two excellent, simple utilities that can be used to spoof MAC addresses of Ethernet cards. They require no special knowledge to use save for knowing which MAC address to spoof. MAC address is explained here.
Linux users ought to consider themselves lucky. The innate “ifconfig” command-line utility natively support MAC address modification (based on the underlying device driver’s support of the same feature for the given Ethernet card). Refer to the man page for ifconfig(8). In particular, the “hw‘ switch to “ifconfig” is the magic argument.
On Slackware, I’ve /etc/rc.d/rc.local set to partially bring up the eth0 Ethernet interface with a modified MAC address (which, for purposes of this post, has been masked to look xxyyzzaabbdd):
ayaz@dante$ tail -4 /etc/rc.d/rc.local
# Drop eth0 and load it with an alternate MAC address.
/sbin/ifconfig eth0 down
/sbin/ifconfig eth0 hw ether xxyyzzaabbdd up
All, then, I have to do when I log into the console is issue as root the “dhclient eth0” command to invoke the DHCP client to fetch a lease.