the itjerk

my adventures with technology

Tag Archives: dynamic

dynamic dns

Most internet providers, heck, most internet connections are dynamic. Your device gets assigned an IP address when it asks for one. Sometimes it’s the same, but more often than not it might be different. DNS works by resolving a hostname like with an ip address, so everytime you type in you go to the same place.

For home computers, this can be problematic. Enter Dynamic DNS services. Every time your IP address changes, the Dynamic DNS service updates the “a record” with the new number so it can continue to resolve. Routers usually have sections to do this, which is good, because they’ll get notified first. It can also be done with other applications, or even with something like cron.

I’ve used DynDns for many years, but they’ve gone from a free service, to a paid service. Even though $5/mo might not seem like a lot, it’s a lot when you have free options. Enter DuckDNS. Although not that extensible, it’s a free service and provides exactly what I need, for free.

On the web:


dynamic port forwarding with ssh

Need to surf securely at work, or on a public wifi? Here's the poor man's vpn. Using an OpenSSH connection to your host machine with the dynamic "-D" flag, you can create a SOCKS proxy for a web browser on another machine. On a Windows machine, you'll need to use Putty to get your ssh connection.
Here's the connection:

ssh -D port user@hostmachine

Once you connect via ssh to your host, configure Firefox to use the SOCKS proxy server. (Options>Advanced>Network>Connections)

For even more security, you can also configure Firefox to route all its DNS requests through the same tunnel. From Firefox's address bar, type "about:config" for "advanced" settings, then look for the key "network.proxy.socks_remote_dns" and set it to true by double-clicking. Done! All your surfing will tunnel through your host machine.

To verify that everything's working, point Firefox here to verify the IP address matches that of the host machine.