Dynamic IP Addresses

As the security of the system is based predominately on IP addresses for security, Dynamic IP addresses make things a wee bit difficult to handle.

The easiest way to achieve this is to give your node a Domain name with freedns. Now most of Freedns's Domains are registered with spam and all sorts of other rubbish, so they are no good for registering websites etc, but they are fine to use for what we need.

The VK3SMB Demo unit has a Dynamic IP address as it is used on 3G connections for demo purposes.

Through Freedns, I have given it a name of vk3smb.mooo.com.

Setting a node name up(Edit)

  1. Go to http://www.freedns.afraid.org
  2. Sign up an account
  3. Choose a subdomain of one of the free domain names
  4. Set an A record to that subdomain
  5. Choose DynamicDNS from the website menu
  6. Get the Direct URL setting from the website and copy it from your web browser bar with CTRL-C

Enabling it on the pi(Edit)

Now that you have a URL for the pi to call at regular intervals, you need to set up a cron-job to call this every 10 minutes and also do it on a reboot.

To set this:

  1. Open the Main Setup Menu
  2. Go to Advanced stuff
  3. choose edit crontab
  4. scroll down the bottom of the file and add the following lines:
  5. @reboot /usr/bin/wget --delete-after "{yourcopiedurl}" & > /dev/null 2>&1
    10 * * * * /usr/bin/wget --delete-after "{yourcopiedurl}" & > /dev/null 2>&1
  6. Press CTRL X, {enter}, y to save the file

Now the Pi has its own domain, and calls any changes, we have to tell the VKLink server all this, for security reasons, or it will simply boot the pi off the list and nobody will be able to connect to it.

  1. Go back into the Main Setup Menu, Select Change Public Node Information.
  2. Scroll down to Change your domain name (fqn), press {enter}
  3. Enter your domain name, ie vk3smb.mooo.com and press {enter}

The server now knows who your pi is and will keep tabs on it.

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