The 5-in-1 Network Admin's Cable


Michael Ossman brings us the handiest little set of network administrator tools you can fit in your mini-screwdriver set. With one standard Ethernet cable, a straight-through coupler, and a few homebrew adapters, you will have:

  1. straight-through ethernet cable:ethernet cable photo

  2. crossover ethernet cable:crossover cable photo

    ethernet - coupler - crossover

  3. modem cable:modem cable photo

    DB9/RJ45 - ethernet - DB9/RJ45

  4. null modem cable:null modem cable photo

    DB9/RJ45 - ethernet - coupler - crossover - DB9/RJ45

  5. Cisco console cable:Cisco console cable photo

    DB9/RJ45 - ethernet - coupler - Cisco adapter

This set is easily expandable with a loopback (which will work on both Ethernet and RS-232, also useful for testing distant connectors) and one-way sniffers.

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Recovering eth0 on Debian after VM clone


After cloning a working Debian virtual machine, the new system would not bring up its Ethernet interface. This is because I checked VirtualBox's dialog, "Reset MAC address for network card" and got a new hardware Ethernet address.

Trying "ifup eth0" didn't work. I did an "ip addr" and saw that the only configured interface was now called eth1.

This is simple to solve. Edit the file /etc/udev/rules.d/70-persistent-net.rules and move the new MAC address (like "00-0F-35-01..." and so on) from the eth1 line back to eth0, erasing the previous address in the eth0 line. Then delete the remainder of the eth1 line, save, and reboot.

You should now have your eth0 back.

Setting up Zonet 2102 print server on Ubuntu Linux


For setup of the Zonet ZPS2102:

The default IP is ... in the Add Printer dialogs, choose Network Printer, then enter the IP address, the queue (default is: LP1) and choose the model.

The Device URI, when you are done, looks like: