Friday, November 17, 2017

Running DNS Server on Ubuntu Linux

This post is written for Ubuntu Linux but, you can easily follow similar steps on your favorite distro. Technitium DNS Server is developed in c# and requires you to have Mono Framework installed on Linux to run it.

Start Terminal and follow the steps below to run DNS Server on Ubuntu:

  1. Install Mono Framework. Skip this step if you already have it installed.
    $ sudo apt-get -y install mono-complete
  2. Download DNS Server from the website using wget as shown below.
    $ wget https://technitium.com/download/dns/DnsServerPortable.tar.gz
  3. Extract the files and start DNS Server.
    $ tar -xvzf DnsServerPortable.tar.gz
    $ cd DnsServer
    $ sudo ./start.sh
    
  4. Open the url http://localhost:5380/ to access the web console.

That's it! The DNS Server is running and you can configure your network with the IP address of this computer for DNS resolution.

Check out the web console to create zone, check cached zones, access DNS client tool and configure server settings.

The DNS Server creates a folder named config in the current folder which contains the server config and zone files. Make sure you copy this folder while moving the DNS server folder if you want all the zone files and config to persist.

If you have any trouble installing mono framework the refer to this official mono installation guide.

For any related queries, feel free to comment on this post.

Technitium DNS Server Released!

Technitium DNS Server is an open source tool that allows anyone to run DNS server on their computer or local network. Its aimed towards software developers who like to simulate live production scenarios on their laptop or local network setup for testing or debugging purposes. However, it can be used for any DNS related requirement. Applications of using your own local DNS server is limited only by the your imagination!

Technitium DNS Server Web Console

The DNS server is cross platform and can be deployed on Windows, Linux or Mac OS (using Mono Framework). The DNS portable console app allows running the service instantly with zero initial configuration, just run the executable and its ready. The DNS server provides web console access that allows it to be accessible over network.

A unique feature available with this server is to enable/disable hosted zones with a single click allowing switching between staging/testing setup to live production setup instantly. Once a zone is disabled, the DNS server will start recursively resolving the domain and use cached results. When the zone is enabled, the records hosted on the server override the cached results. This reduces a lot of efforts when trying to achieve similar thing using hosts file. Hosted records can be set with low TTL values to force the operating system DNS client to re-query.

The DNS server has many standard features like recursion, caching, wildcard sub domains, forwarders, IPv6 support etc. A very useful and frequently used feature is the DNS Client tool included with the web console. This DNS Client tool is a general purpose DNS resolver that can be used to query any name server accessible over the network. The DNS Client can also perform recursive query on its own and display results from the authoritative name server for the given domain. The recursive query feature saves time by automatically finding out the authoritative name servers via the root servers. DNS Client is also available as a separate online tool at dnsclient.net website.

Apart from just resolving queries, the DNS Client also provides a very useful feature to import records from the output of the query into the local DNS. This feature is really useful when you quickly want to copy existing records for a given domain. You can query with type ANY which would list out all possible records or use specific type needed, and import them in one go into the local server zone. You may then edit a few records with value that you need for testing and its ready to use. With query type ANY, its advised to use TCP protocol since the UDP protocol may not accommodate all the records resulting in a truncated response.

Technitium DNS Server include following features:

  • Fully manageable local DNS server.
  • Wildcard sub domain support.
  • Disable/Enable hosted zones for quick switching between staging & production.
  • DNS Client tool for resolving queries.
  • Import records feature allows to import records of live domain using DNS Client.
  • Recursive querying support.
  • Web console for allowing access over network.
  • DNS caching with cache viewer interface in web console.
  • Forwarders setup to allow chaining other DNS server to reduce response time.
  • IPv6 network support in DNS server core for querying.
  • Cross platform implementation for running on Linux or Mac using Mono Framework.

There are many applications of having a self hosted local DNS server. Some of them are:

  • Software developers or web developers can simulate live setup without need to use hosts file.
  • Security researchers can use it in their lab setups for spoofing domain names while performing experiments.
  • Users can keep watch on domain being used by various applications using the Cached Zone listing.
  • Block certain domains to partially or fully fail a website/application feature. User can block domain by creating an empty zone such that the application/website using that domain can no longer get the right IP address to the server failing all requests.

The DNS Server currently lacks feature to display stats and writing access logs which will be added later in coming versions. It also must be noted that this DNS server is not suitable to be used for production or any critical application. The software is released as alpha version denoting that its not yet stable and may have bugs.

Technitium DNS Server is open source and available under GNU General Public Licence (GPL) v3 on GitHub.

Comments and feedback are things that help push new features and improve usability, and thus are most welcome. Send your feedback to support@technitium.com or leave your comments below.

Sunday, July 23, 2017

Bit Chat 4.6 Released

Technitium Bit Chat is a secure, peer-to-peer (p2p), open source instant messenger designed to provide end-to-end encryption. Primary aim of developing this instant messenger is to provide privacy which is achieved using strong cryptography. It can be used over Internet and private LAN networks for instant messaging and file transfer.

Bit Chat v4.6

Technitium Bit Chat version 4.6 (alpha) is available to download from the main website and via automatic update mechanism for existing installations. The software checks for new update automatically with every start but, you can also use the Check For Updates option in the main menu to get an update instantly.

Bit Chat v4.6 Released

The latest update has some protocol level changes that are not compatible with previous versions. Due to this, all peers will need to update to the latest version to be able to chat.

This update adds TCP based DHT protocol and removed UDP support totally. DHT over UDP faced issues with networks where inbound UDP packets are blocked over Internet. The Bit Chat protocol also adds a decoy HTTP GET requests to bypass application firewalls.

Know more about Bit Chat by reading Frequently Asked Questions (FAQ) and Bit Chat whitepaper. You can also view Bit Chat source code on GitHub and compile Bit Chat client yourself.

And as always, send your feedback to support@bitchat.im or write your comments below.