powered by sleep

If you are using SSH to tunnel your web traffic, to keep your information private, you might be vulnerable to a DNS man-in-the-middle attack.  If your DNS requests aren’t tunneled, the operator of the hostile (or locked down) network can still see where you are navigating to on the web when your client makes DNS requests to resolve hostnames to IP addresses.
For these reasons (and for many others), it’s a good idea to tunnel DNS through your SSH tunnel too.  This can be done very easily in Firefox.

In the Firefox URL address bar, enter “about:config“.
In the Filter text field, enter “network.proxy.socks_remote_dns“.
Double-click “network.proxy.socks_remote_dns” to set the value to true.

After a recent Ubuntu Linux (server) installation inside in a virtual machine, I decided to move the virtual machine to new a new host where I can run it.  After the move I noticed that I could no longer connect to my system via the IP I had assigned.  So the story begins.

With the discovery that I no longer had network connectivity, I did an ‘ifconfig’ and noticed that my eth0 was missing.  So, I tried to force it to start by issuing the command ‘ifup eth0’ and go the following error:

eth0: ERROR while getting interface flags: No such device…
SIOCSIFADDR: No such device
eth0: ERROR while getting interface flags: No such device
eth0: ERROR while getting interface flags: No such device
Bind socket to interface: No such device
Failed to bring up eth0

I did some searching, as I have run into this issue in my past and could not remember for the life of me what I needed to do to correct this problem (the right way).  The method I used in the past was to edit /etc/network/interfaces and change iface eth0 inet (static or dhcp) to eth1  This would change my static or dynamic settings to use the new interface…  This is not what I wanted to; “lazy admin approach”.

What I did do is… wait! Here is some background info:  When a Virtual Machine starts up, it generates a new MAC address and a new UUID for the guest system. My system had already known of a MAC address and thus made a new one.

Back to what I did to correct my problem

Locating the file /etc/udev/rules.d/70-persistent-net.rules, I removed the former MAC address info and modified the new one, changing the existing eth1 to eth0, and issued a restart

Example:
# PCI device 0×8086:0x100f (e1000)
SUBSYSTEM==”net”, DRIVERS==”?*”, ATTRS{address}=”[bad mac]“, NAME=”eth0″