Technical Tip: Change DNS on appliances
Description
This article describes how to change IP Addresses of DNS Servers.
Scope
FortiNAC.
Solution
Two files are used for DNS name resolution:
- zones.common: used for name resolution for hosts in isolation. When resolving names that are in the Allowed Domains list, this file is used to determine which DNS server to send requests on behalf of the isolated host.
- resolv.conf: used for name resolution for the appliance.
The following instructions are used when the production DNS server IP addresses need to be changed.
Updating zones.common:
- In the Administration UI, navigate to System -> Settings -> Allowed Domains.
- Update the IPs under the banner of the IP Address
- Select Save Settings (this will take a few moments).
Updating resolv.conf (must be done on all appliances):
Single appliance:
- Run a Configuration Wizard on the Server.
http://<IP Address>:8080/configWizard
http://<Host Name of the appliance>:8080/configWizard
http://<Host Name of the appliance>:8080/configWizard
- In the Basic Network screen, update the appropriate IP address under the DNS section.
- Select Summary.
- Apply (this will take a few moments).
Control Server/Application Server pair:
- In the Application Server CLI, start the tomcat-admin service (this will allow Config Wizard to be accessible).
service tomcat-admin start
- Run Configuration Wizard on the Application Server.
http://<IP Address>:8080/configWizard
http://<Host Name of the appliance>:8080/configWizard
- In the Basic Network screen, update the appropriate IP address under the DNS section.
- Select Summary.
- Select Apply (this will take a few moments).
- Close Configuration Wizard and stop the tomcat-admin service.
service tomcat-admin stop
- Run the Configuration Wizard on the Control Server.
- Select Summary.
- Select Apply.
If the Configuration Wizard cannot be used:
In the CLI of each appliance, edit /etc/resolv.conf and save.
In the CLI of each appliance, edit /etc/resolv.conf and save.
Important: CLI method should only be used when Configuration Wizard cannot be run. Otherwise, the next time the Configuration Wizard is run, resolv.conf will be overwritten with the old settings (unless updated).
L2 High Availability Environments
:
:
- Update zones.common (see instructions above).
- Update resolv.conf on the Primary Server via configWizard (see instructions above).
- Update resolv.conf on the Secondary Server via configWizard. Access configWizard using the address of the Secondary Server.
Note: In older versions, the Secondary address may not be available in a Layer 2 High Availability configuration (Virtual IP is configured). In such cases, a modification of the /etc/hosts file on the Secondary Server is necessary. For instructions, refer to section Access Secondary Server Wizard Post HA Configuration in the High Availability reference manual in the Fortinet Document Library.
