Dynamic DNS Set Up

Dynamic DNS (DDNS) is a system that automatically updates DNS records when an IP address changes. It allows you to connect to a server using a domain name without worrying that its dynamic IP address may change.

Entities on the cMix network communicate using IP addresses or domain names. If a Node or Gateway uses a dynamic IP, then changes in the IP address can result in downtime until the Node operator manually updates it. To avoid this downtime, DDNS can be used so that entities contact your Node or Gateway using a domain name rather than an IP address that can change. If an IP address changes, it will quickly be updated in the DNS records, and entities on the network should continue to communicate with your Node or Gateway.

Once you have set up DDNS and have a domain name linked to your Node or Gateway, follow the instructions below for configuring the cMix software to utilize it.

If your Node or Gateway has a static IP address, then there is no need to use dynamic DNS. However, you are still welcome to use a domain name by following the instructions below.

Setting the Domain Name on cMix Node

To use DDNS on the Node, you must enable overridePublicIP on the Node and update the cmixAddress on the Gateway with the Node's domain name.

Update the Node

Follow the instructions below on the Node machine.

1. Open up the cMix configuration file.

   $ sudo nano /opt/xxnetwork/config/cmix.yaml
   

2. Use the down key ↓ to navigate to the line with #overridePublicIP (it will be under cmix > paths) and uncomment it by deleting the # prepending the line. Replace the placeholder IP address with the domain name for your cMix Node.

     GNU nano 4.8
   
   /opt/xxnetwork/config/cmix.yaml
   Modified  
     # Local IP address of the Node, used for internal listening. Expects an IPv4
     # address without a port. (default "0.0.0.0")
     # WARNING: Do not modify this option unless explicitly required.
     #listeningAddress: "0.0.0.0"
     # The public IPv4 address of the Node, as reported to the network. When not
     # set, external IP address lookup services are used to set this value. If a
     # port is not included, then the port from the port flag is used instead.
     # WARNING: Do not modify this option unless explicitly required.
     overridePublicIP: "cmix.example.com
   Put your cMix Node's domain name."
     # If set, then it is used to override the internal IP address used to contact
     # yourself. Expects an IPv4 address with or without a port. If no port is
     # included, then the port from the port flag is used.
     # WARNING: Do not modify this option unless explicitly required.
     #overrideInternalIP: "0.0.0.0"
   
   ^G Get Help
   ^X Exit
   ^O Write Out
   ^R Read File
   ^W Where Is
   ^\ Replace
   ^K Cut Text
   ^U Uncut Text
   ^J Justify
   ^T To Spell
   ^C Cur Pos
   ^_ Go To Line
   

If the port for the domain name is different than the one specified in the port field, then include it in the address for overridePublicIP

3. Once the change is made, save the file by pressing Ctrl+X, and when prompted to save the buffer, press Y. Finally, when prompted with the file name, press ↵ Enter.

4. To activate the change, restart the cMix service.

   $ sudo systemctl restart xxnetwork-cmix.service
   

Update the Gateway

Follow the instructions below on the Gateway machine.

1. Open up the Gateway configuration file.

   $ sudo nano /opt/xxnetwork/config/gateway.yaml
   

2. Use the down key ↓ to navigate to the line with cmixAddress and replace the IP address with the domain name and port for your cMix Node.

     GNU nano 4.8
   
   /opt/xxnetwork/config/gateway.yaml
   Modified  
   
   # The IP address of the machine running cMix that the Gateway communicates with.
   # Expects an IPv4 address with a port. (Required).
   cmixAddress: "cmix.example.com:11420
   Put your cMix Node's domain name and port."
   
   ^G Get Help
   ^X Exit
   ^O Write Out
   ^R Read File
   ^W Where Is
   ^\ Replace
   ^K Cut Text
   ^U Uncut Text
   ^J Justify
   ^T To Spell
   ^C Cur Pos
   ^_ Go To Line
   

   Ensure that cmixAddress address has a port. The default port is 11420.

3. Once the change is made, save the file by pressing Ctrl+X, and when prompted to save the buffer, press Y. Finally, when prompted with the file name, press ↵ Enter.

4. To activate the change, restart the cMix service.

   $ sudo systemctl restart xxnetwork-gateway.service
   

Setting the Domain Name on cMix Gateway

To use DDNS on the Gateway, you must enable overridePublicIP and configure it with the Gateway's domain name.

1. Open up the Gateway configuration file.

   $ sudo nano /opt/xxnetwork/config/gateway.yaml
   

2. Use the down key ↓ to navigate to the line with #overridePublicIP (it should be at the bottom) and uncomment it by deleting the # prepending the line. Then replace the placeholder IP address with the domain name for your cMix Gateway.

     GNU nano 4.8
   
   /opt/xxnetwork/config/gateway.yaml
   Modified  
   ##
   # WARNING: Do not modify the options below unless explicitly required.
   ##
   
   # Local IP address of the Gateway, used for internal listening. Expects an IPv4
   # address without a port. (Default "0.0.0.0")
   #listeningAddress: "0.0.0.0"
   
   # The public IPv4 address of the Gateway, as reported to the network. When not
   # set, external IP address lookup services are used to set this value. If a
   # port is not included, then the port from the port flag is used instead.
   overridePublicIP: "cmix.example.com
   Put your cMix Gateway's domain name."
   
   ^G Get Help
   ^X Exit
   ^O Write Out
   ^R Read File
   ^W Where Is
   ^\ Replace
   ^K Cut Text
   ^U Uncut Text
   ^J Justify
   ^T To Spell
   ^C Cur Pos
   ^_ Go To Line
   

   If the port for the domain name is different than the one specified in the port field, then include it in the address for overridePublicIP

3. Once the change is made, save the file by pressing Ctrl+X, and when prompted to save the buffer, press Y. Finally, when prompted with the file name, press ↵ Enter.

4. To activate the change, restart the cMix service.

   $ sudo systemctl restart xxnetwork-gateway.service