Running DNS Server on Ubuntu Linux

Technitium DNS Server is build to be cross platform using the .NET Standard 2.0. You can run the DNS Server Portable App on Linux or macOS by using Mono Framework or .NET Core 2.0. This post is written for Ubuntu Linux but, you can easily follow similar steps on your favorite distro.

Using Mono Framework

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. Install unzip. Skip this step if you already have it installed.

   $ sudo apt-get -y install unzip

3. Download DNS Server Portable App zip file using wget as shown below.

   $ wget https://technitium.com/download/dns/DnsServerPortable.zip

4. Extract the files and start DNS Server.
   

   $ unzip DnsServerPortable.zip
   $ cd DnsServer
   $ sudo mono DnsServerApp.exe
   

5. Open the url http://localhost:5380/ to access the web console.

Using .NET Core

Download the latest .NET Core runtime (tar.gz) file from here. Start Terminal and follow the steps below to run DNS Server on Ubuntu:

1. Assuming the downloaded runtime file is in Downloads folder. Follow below step to install it. Skip this step if you already have it installed.

   $ cd ~/Downloads/
   $ sudo mkdir /usr/share/dotnet/
   $ sudo tar -xzvf dotnet-runtime-2.0.4-linux-x64.tar.gz -C /usr/share/dotnet/
   $ sudo ln -s /usr/share/dotnet/dotnet /usr/local/bin/
   

2. Download DNS Server Portable App tar.gz file using wget as shown below.

   $ wget https://technitium.com/download/dns/DnsServerPortable.tar.gz

3. Extract the files and start DNS Server.
   

   $ tar -xzvf DnsServerPortable.tar.gz
   $ cd DnsServer
   $ sudo ./start.sh
   

4. Open the url http://localhost:5380/ to access the web console.

You may get this error shown below when you start DNS Server:

Unhandled Exception: System.Net.Sockets.SocketException: Address already in use
   at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, String callerName)
   at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.Sockets.Socket.Bind(EndPoint localEP)
   at DnsServerCore.DnsServer.Start()
   at DnsServerCore.DnsWebService.Start()
   at DnsServerApp.Program.Main(String[] args)
Aborted (core dumped)

This error means that another application is already running on the DNS UDP 53 port. On Ubuntu, usually its dnsmasq service running. You may confirm this by running sudo netstat -nlpu command. Follow the steps below to disable the dnsmasq service:

1. Edit the NetworkManager.conf file to disable dnsmasq service:

   $ sudo nano /etc/NetworkManager/NetworkManager.conf
   

   Comment out the dns=dnsmasq line by adding # character at the beginning like this #dns=dnsmasq and exit the editor by pressing CTRL+X and enter y to save the file.
2. Restart the computer to apply changes as shown below:

   $ sudo reboot now
   

3. After system reboot, open Terminal and try again to start DNS Server.

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 macOS (using Mono Framework or .NET Core). 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.
• Built-in system logs and query logs.
• Cross platform implementation for running on Linux or macOS using Mono Framework or .NET Core.

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.

It 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.

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.

Announcing Technitium DNS Client Service

Technitium DNS Client is a simple domain name lookup service to quickly query any name server including root servers.

Technitium DNS Client

You can use it to confirm any DNS changes that you made to your domain. Selecting root server option to query a domain will, automatically resolve the authoritative name servers via root servers and get the response from them.

The response displayed is JSON formatted output of the DNS datagram which contains all necessary fields including fields from the header.

Technitium DNS Client is intended to be useful for domain administrators to verify the the changes they made to the zone with ease.

The source code for DNS Client is available on GitHub.

And as always, send your feedback to support@technitium.com or write your comments below.

Technitium web hosting facing temporary issues

We are facing issues with web hosting since yesterday due to which there are intermittent down times. You may get "HTTP Error 503. The service is unavailable." error on technitium.com as well as bitchat.im. The Bit Chat registration service is also affected.

We are trying to restore the website partially for time being till all the issues are resolved.

Update (25-oct-2016): Issue with hosting seems to be fixed now and things are working.

Bit Chat v4.5 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 v4.5

Technitium Bit Chat version 4.5 (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 v4.5 Released

The latest update includes many protocol level changes which are not compatible with previous versions, due to this, all peers will need to update to the latest version to be able to chat. The latest version fixes some bugs and adds new features that are mentioned below:

• Private Chat Invitation feature allows you to invite any online Bit Chat user to chat privately. This feature provides much needed initial contact mechanism to add contacts. The working mechanism relies on DHT and thus requires at least one DHT node available globally to work on the Internet. The feature works without DHT on local LAN networks to directly send invitation message to peers on the same local network. It may take a couple of minutes for the invitation message to reach the peer over the Internet. You can manage the invitation feature options from your Profile Settings.

  

  Private Chat Invitation

• Group Image feature allows setting a custom image to group chats. Any user in the group can update the image and the latest image is automatically synced across all other peers in the group.

  

  Group Image Viewer

• Change Shared Secret feature is now available from chat properties to allow peers to decide and set a new shared secret easily without having to create a new group.

• You can now Mute chat to avoid getting message notifications using the Mute option in the chat list context menu.

• New message view interface shows each message in a separate bubble for a better user experience. Shared files are also listed as messages in the view and allows you to access all file sharing options via the context menu.

• You can now share an already shared file in one chat to all other chats by using Share With option in the file sharing context menu.

  

  Share File With Option

• Message Delivery feature let you know if the message was delivered to other peers using tick icons at the bottom of each sent message. You can also view detailed message delivery info from the Message Info option in the context menu.

  

  Message Delivery Info

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.

Bit Chat v4.2 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 v4.2

Technitium Bit Chat version 4.2 (alpha) is now 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 v4.2 Released

The latest update includes many protocol level changes which are not compatible with previous versions, due to this, all peers will need to update to the latest version to be able to chat. The latest version fixes some bugs and adds new features that are mentioned below:

• Profile Image feature added to allow user to set a custom profile picture which is visible to all other peers.
  

  

  Bit Chat User Profile Viewer

• Messages Store implemented to store all Bit Chat messages locally in an encrypted format so that, you don't lose all your conversations and don't have to worry about the security of the stored messages. All messages are stored securely using AES 256-bits encryption algorithm and can only be read using the profile password.
• Bit Chat now fully supports IPv6 protocol and implements local peer discovery using IPv6 multicast.
• Proxy settings have new Socks 5 (Tor Network) option to allow quick configuration.
• Go Offline feature added to allow you to disconnect a private chat or chat group without having to delete the chat by leaving it.
• Bit Chat Portable feature allows you to use Bit Chat without installing it on your computer. You can keep copy of the portable binaries on removable media like USB drives and carry Bit Chat with your profile to any other computer.

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.

Technitium MAC Address Changer v6.0.7 Released

Technitium MAC Address Changer v6.0.7 is now available for direct download and via Automatic Update. You can download the latest version release from this direct download link or via this official torrent.

Technitium MAC Address Changer

The software will check for update automatically as per a fixed schedule. If you want the update before the automatic update triggers, just start the software, click on Help > Check For Software Updates menu to get it done instantly.

This update fixes following issues:

• OUI file update from IEEE.ORG fixed by updating file parser due to changes in the published file format.
• Fixes error handling while reading IPv4 information.
• Fixes some UI components that were getting distorted for some users.

You can read help topics for getting answers to common queries.

For any queries or issues related to this release, just post a comment below. You can also send screenshots of the software to support@technitium.com for feedback.

Bit Chat v4.1 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.

Technitium Bit Chat version 4.1 (alpha) is now 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 v4.1 Released

The latest update includes some protocol level changes which are not compatible with previous versions, due to this, all peers will need to update to the latest version to be able to chat. The latest version fixes some bugs and adds new features that are mentioned below:

• HTTP Proxy support now added with existing Socks 5 proxy support.
  

  

  Bit Chat Http Proxy Config

• Kademlia based Distributed Hash Table (DHT) now supports using both UDP and TCP (via proxy). The TCP protocol support allows peers who are using proxy to use the DHT feature.

Know more about Bit Chat by reading Frequently Asked Questions (FAQ). 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 add comments below.

How To Register Profile & Get Started With Bit Chat

Bit Chat is an open source, instant messenger, base on peer-to-peer technology that allows people to chat with each other by directly connecting via a secure TCP based protocol without any 3rd party server in between. The TCP based protocol implements end-to-end encryption to allow people share information securely. Due to the peer-to-peer nature of connectivity, it becomes necessary to have some sort of method to identify and verify the person you are chatting with.

For this reason, Bit Chat uses a profile certificate (a digital certificate) which is issued to each user after email address verification. This allows peers to be identified by their email address.

The profile certificate is exchanged with each peer that you chat with. It contains all the details that you enter during the registration process and hence its recommended that you keep your information brief enough to allow other users to identify you.

Profile Registration

Profile registration is a one time process that you need to do for using Bit Chat. On starting Bit Chat for first time, you will get a welcome screen. Click on the Register Now! button to proceed with registration.

Bit Chat Welcome Screen

If you already have registered a profile and want to use it on another computer, you can export the profile file from existing computer and import it using the import profile option in the welcome screen.

Bit Chat Profile Registration

Once you proceed with new registration, you will get a Profile Registration window shown above. Enter your details in brief so that your peers can identify you. As mentioned earlier, all the information provided in this registration form will be visible to your peers. Your name, email address and country details are required fields and you can choose to leave all other fields empty.

You must not use email address alias for registration since, confirming your email address requires you to be able to reply to the confirmation email with the same email address provided during registration. Any mismatch in the 'From:' email address will not be considered for email verification.

You may wish to hide your IP address during registration by using the Enable Proxy option which can be configured to use any available Http or Socks 5 proxy server including Tor. Alternatively, you can also use any of the anonymous VPN services.

The profile registration process generates a RSA 4096 bit key pair which is used for generating and verifying digital certificate. The key can be automatically generated by Bit Chat or alternatively you can use tools like openssl to generate a key in PEM format and import it using the Import custom RSA 4096-bit key pair option.

The profile data is stored on your computer as a separate file. Since this file contains your RSA private key and your registration details it becomes important to store it securely. To protect the profile data it is encrypted by AES-256 encryption using a profile password. This profile password is not stored anywhere and cannot be recovered in case you forget it. It is important to use a strong password/passphrase and memorize it. In case of forgetting this password, you will have to register a new profile using the same email address.

Once you have completed filling all the necessary information, accept the terms and conditions after reading it and click on the Register button to proceed. It may take a while for the registration to complete since there might be a delay due to generation of RSA key pair on your computer. Once the registration request is submitted to the server, you will get an email for verification.

Bit Chat Profile Registration

The profile certificate is issued by the server upon email verification. To verify your email address, you need to reply to the verification email that you have received without changing the subject. You don't need to write anything in the email itself for this step. You should make sure that when you reply to this verification email, your From email address must match with the one provided during the registration. Using email address alias wont work for verification.

Bit Chat Verification Email

The email verification process takes a minute or two and you will receive a final email notification which completes the registration process. Upon receiving this notification email, you can click Start Bit Chat button in the registration window to proceed using Bit Chat.

Bit Chat Notification Email

You can view your profile certificate by clicking on your name that appears in the top left corner of the Bit Chat main window. The profile certificate looks like the one shown in the image below. The fields in green indicate that those were verified by the certificate issuer before signing it. In your case, the email address will be green indicating that it was verified successfully by the issuer. You can explore more technical information in the Details tab of the certificate viewer.

Bit Chat Profile Certificate Viewer

You can now create new group chat or private chat and ask your friends to join you on Bit Chat. Bit Chat does not have any option to directly send a contact request to your friends since we do not wish to know to whom you chat with. You can invite your friends by sending them details by email or via another instant messenger.

For any queries leave a comment below or send an email to support@bitchat.im.