The following section outlines the steps to configure DNS Statistics. If you are configuring DNS Statistics to send data to a Splunk server, ensure that you have the Splunk HTTP Event Collector (HEC) host and token information.
To configure DNS Statistics on a DNS/DHCP Server:
- From the configuration drop-down menu, select a configuration.
- Select the Servers tab.
- Under Servers, click the name of a BDDS. The Details tab for the server opens.
- Click the server name menu and select Service Configuration.
- From the Service Type drop-down menu, select DNS Statistics under the Health Telemetry section. Address Manager queries the server and returns the current values for the service settings.
Under General Settings, set the following
- Enable DNS Statistics—select this check box to
enable DNS Statistics service; deselect this check box to disable DNS
Statistics service.Note: When you enabled DNS Statistics, the firewall rules on the DNS/DHCP Server are modified to allow egress to the specified URI endpoint. Outbound traffic is allowed for the specified IP address.
- Polling Interval—set the frequency at which the DNS statistics events are polled. The minimum value is 1 minute and the maximum value is 30 days.
- Output Type—select where the DNS Statistics data
will be logged. You can select HTTP to log data to an HTTP
endpoint or Splunk to log data to a Splunk server.If you select HTTP, the following fields appear:
If you select Splunk, the following fields appear:
- Output URI—enter the URI of the HTTP
endpoint that will be consuming the DNS statistics
- BlueCat recommends entering the IP address of the endpoint in this field. If you are entering a hostname, you must use a different DNS server as the resolver for that host. The DNS/DHCP server you are configuring DHCP statistics on can still be used as a resolver for clients, but cannot be used as a resolver for its own OS related lookups.
- If the domain name is used in the URI, you must ensure that the domain name can be resolved on the DNS/DHCP Server using nslookup or an entry in /etc/hosts.
- If you have round-robin DNS load balancing configured, the firewall is set for all IP addresses returned for the specified domain and outbound TCP connections are allowed for all IP addresses.
- Bearer Token (Optional)—enter the bearer token used to authenticate with the HTTP endpoint.
- Healthcheck—select this check box to enable health check service; deselect this check box to disable health check service. Upon initialization, the healthcheck ensures that the downstream service is accessible and can accept the DNS statistics data.
- Healthcheck URI—enter the URI of the HTTP endpoint that will be consuming the health check information.
Note: The URI of the Output URI, Healthcheck URI, and Host fields must follow the format outlined in RFC2396.
- Host—enter the URI of the Splunk HEC
host. The standard format of the HEC URI in Splunk
Enterprise is as follows:
<protocol>://<FQDN of the host only>:<port>Note:
- Ensure that the HEC URI format is followed exactly as described above without adding or omitting any pieces. The port is required, even if default. Do not include extra slashes or folders in the URI.
- Token—enter the Splunk HEC token.
- Healthcheck—select this check box to
enable health check service; deselect this check box to
disable health check service. Upon initialization, the
healthcheck ensures that the downstream service is
accessible and can accept the DNS statistics data.
Note: When selecting this check box, the DNS/DHCP Server uses the default Splunk healthcheck endpoint at /services/collector/health/1.0.
- Output URI—enter the URI of the HTTP endpoint that will be consuming the DNS statistics information.
- TLS Options—select this check box to configure
TLS options. Attention: If you enter a HTTPS endpoint in the Output URI or Healthcheck URI field when configuring HTTP as the Output Type, or enter a HTTPS URI in the Host field when configuring Splunk as the Output Type, you must select this check box and enter TLS information.
- Under CA Certificate Upload, click
Browse and locate the CA certificate
(trusted third party or self-signed) that will be used to
authenticate the CA signature on the TLS server certificate of
the remote host.Note: The file containing the CA certificate or certificate bundle must be in PEM format. To ensure a successful TLS handshake, the CA certificate uploaded to the client (BAM) should be the same CA certificate (and intermediate certificates if applicable) used by the server to authenticate the CA signature of its TLS server certificate. The CA certificate can be acquired via browser export or other trusted source, and converted to PEM format.
- Click Upload to upload the CA certificate.
- Select the Verify Certificate check box
to attempt a TLS handshake using the uploaded CA certificate
with the remote host's TLS server
certificate.Note: Verify Certificate does not verify the authenticity of the uploaded certificate. Verify Certificate in this context only checks if the CA certificate matches correctly with the TLS server certificate to create a successful handshake.Note: If encountering errors with Verify Certificate, the CA/chain-CA certificates may have to be installed manually on the DNS/DHCP Server. Refer to KB-17944 on the BlueCat Customer Care portal for manual installation instructions.
- Select the Verify Hostname check box to
validate the hostname part of the URI against the CN (Common
Name) or SAN (Subject Alternative Name) of the server
certificate during the TLS handshake.Note: If using self-signed certificates, users are advised to add a subject alternative name with the IP address (see RFC 5280 188.8.131.52), or disable the Verify Hostname check.
- Under CA Certificate Upload, click Browse and locate the CA certificate (trusted third party or self-signed) that will be used to authenticate the CA signature on the TLS server certificate of the remote host.
- Enable DNS Statistics—select this check box to enable DNS Statistics service; deselect this check box to disable DNS Statistics service.
Under Buffer, set the following parameters:
- Max Events—enter the maximum number of DNS statistics events to be stored in the memory buffer. The maximum value is 36,436,000 events.
If you do not have DNS service deployed to the DNS/DHCP Server, after you click Update, you must perform a DNS deployment on the DNS/DHCP Server for DNS Statistics events to be generated. If DNS service is already configured on the DNS/DHCP Server, the DNS Statistics service is enabled upon clicking Update.
Under DNS Statistics Status, you can verify whether the DNS Statistics log service is running on the DNS/DHCP Server.
The service batches data that is sent to the configured destination. Batches are flushed from the system and sent to the configured destination when the age of the batch reaches 1 second, or when the size of the batch reaches 1049000 bytes.
If the service receives an HTTP response status code of 429 or greater than 500 except for 501, the service attempts to retry sending the failed request 5 times. If the service still cannot send the failed request after 5 attempts, the event message is dropped and an error message is logged.
In the event of a service disruption, such as a network error or the system crashes, DNS Statistics service attempts to mitigate event loss. If you enable the Disk buffer type, in the event that the system goes down, the messages are copied to disk and sent when the service is restored. In the event of network connectivity issues, the service retries failed requests. There might be a loss of data if the DNS Statistics process stops on the DNS/DHCP Server while DNS service is running and processing DNS statistics.