5.4. Enabling eDNS on an existing RHEL installation

Prerequisites

• Commands that start with the # command prompt require administrative privileges provided by sudo or root user access. For information on how to configure sudo access, see Enabling unprivileged users to run certain commands.
• Have an existing RHEL installation.

• The following packages are installed on your system:

  • dnsconfd
  • dnsconfd-dracut
  • grubby
• If on an IBM Z system, the zipl utility is installed.

Verification

• Verify your eDNS configuration:

  $ dnsconfd status

  Expected output:

  Running cache service:
  unbound
  Resolving mode: exclusive
  Config present in service:
  {
      ".": [
          "dns+tls://198.51.100.143#dot.dns.example.com"
      ]
  }
  State of Dnsconfd:
  RUNNING
  Info about servers: [
      {
          "address": "198.51.100.143",
          "port": 853,
          "name": "dot.dns.example.com",
          "routing_domains": [
              "."
          ],
          "search_domains": [],
          "interface": null,
          "protocol": "dns+tls",
          "dnssec": true,
          "networks": [],
          "firewall_zone": null
      }
  ]

• Verify that the DNS server is responsive by using nslookup:

  $ nslookup <domain_name>

  Replace the <domain_name> with the domain that you want to query.

Troubleshooting

• Enable detailed logging in unbound:

  # unbound-control verbosity 5

• Review logs for the relevant service:

  $ journalctl -xe -u <service_name>

  Replace <service_name> with NetworkManager, dnsconfd, or unbound.