Manage DNS records (advanced mode with balancing) – Gcore

Create
1. Records settings
2. Record type
3. Domain or subdomain the record belongs to
4. Content of the record
5. TTL
6. (Optional) Additional records of the selected type
7. (Optional) Balancing
• by coordinates (Geo Proximity)
• by ASN, country, or continent (Geo DNS)
8. (Optional) A maximum number of responses
9. Completing the configuration
Edit
Delete

This article explains how to create DNS records in the advanced mode of Gcore DNS Hosting. Interface mode differences are described in the "Getting started with DNS" article.

Create a DNS record

1. Go to records settings

Open the All zones tab and select the domain zone you want to add records for. Click the domain zone or click Go to records in the menu that appears when you click on three dots opposite the domain zone. Alternatively, click on the domain name in the "Quick zone selection" list on the left.

The DNS record management page will open. Click Add record set there and proceed with other steps.

2. Select the record type

In the "Type" section, select the type of DNS record. Our service supports the following types:

A record, which defines the IPv4 address the domain corresponds to. A record is for IPv4 addresses in the format 1.2.3.4.
AAAA record, which defines the IPv6 address the domain corresponds to. AAAA record is for IPv6 addresses in the format 7625: 0d18: 1fa3: 07d7: 1f44: 8a2e: 07a0: 678h.
NS record, which defines the addresses of DNS servers serving the domain
CNAME record, which maps resource records of one domain to resource records of another
MX record, which defines the server that receives mail for the domain
TXT record, which defines auxiliary information about the domain, such as SPF rules
SRV record, which defines the server that operates certain services for the domain
CAA record, which defines the certificate authorities allowed issuing an SSL/TLS certificate for the domain name.

3. Specify the subdomain the record belongs to

In the "Name" field, specify which domain or subdomain the record belongs to.

Leave the field blank for the main domain (apex/naked domain),
Enter the name of the specific subdomain for a subdomain (e.g., "one" for one.testdomain.com), or
Enter an asterisk (*) for all subdomains simultaneously (wildcard record).

4. Specify the content of the record

Fill in the "Content" field with an appropriate value for the record type.

Record type	Value
A	The IPv4 address of the server hosting your website. Example: 1.2.3.4
AAAA	The IPv6 address of the server hosting your website. Example: 7625:0d18:1fa3:07d7:1f44:8a2e:07a0:678h
NS	The name of the zone you want to delegate your domain to. Example: ns1.example.com
CNAME	The domain or domain zone name that your domain should reference. Example: cdn.testdomain.com
MX	The name of the mail server that receives mail for your domain. Example: ASPMX.L.GOOGLE.COM If you use multiple mail servers, fill in the "Priority" field for each server. The lower the value in this field, the higher the priority.
SRV	The canonical name of the machine providing the service. The SRV record contains 4 elements: priority, weight, port, and target. Example: 0 5 5060 sipserver.example.com
TXT	Textual information the record should contain. Example: logmein-verification-code=976afe6f-8039-40e4-95a5-261b462
CAA	Defines the certificate authorities that are allowed to issue an SSL/TLS certificate for the domain name. The record consists of three parts separated by a space: CAA [flags] [tag] "[value]" The "value" must be enclosed in double-quotes (""). Example: 0 issue "comodo.com"

5. Specify TTL

TTL (time to live) is the interval in seconds that servers on the internet use to check if the DNS records for your domain have changed. For example, an A-record has a TTL of 300. If you change the value of this record from "10.0.0.1" to "10.0.0.0", within 5 minutes, users requesting your domain will be sent to a server with IP 10.0.0.1 (this value will be stored in the cache of recursive DNS servers). However, after 5 minutes, the DNS server will check the settings and see the new value of the A-record. When your domain is requested, the DNS server will send users to the server with IP 10.0.0.0.

6. (Optional) Add additional records of the selected type

You can add multiple records of the same type to your domain. Click Add record to add another record. A new line will appear, there you can enter the content of the second record and the associated metadata (read about metadata in step 7). Any record can be deleted by clicking the — button next to it.

7. (Optional) Configure balancing

Our DNS server can give different DNS records to different users, for example, sending users from Asia to an Asian server and European users to a European one. This is called balancing. To enable balancing, move the slider in the "Records selection using metadata" section. If balancing is not needed, leave the slider disabled and go to step 8.

Balancing is based on the metadata you add to each record. You can add seven types of data: coordinates, ASN, continent, country, fallback, or notes. The system will check if a user corresponds to the specified parameters: if they do, the system will give the record; if not, it will not. For example, you can add metadata of the "continent" type with the value "Africa" to a record, which will only be given to users from Africa.

There are two types of balancing available: by coordinates and by ASN/country/continent.

Balancing by coordinates (Geo Proximity)

To assign coordinates to each record, add the latlong (latitude and longitude) type metadata to the records. When a user requests your domain, they will receive the record with the nearest coordinates. You can use the map icon to ensure you've entered the correct coordinates. Just click on the icon, and you'll see the location corresponding to your parameters.

For example, a user closer to the coordinate 51.52318152049715/-0.13458412218999416 (the center of London) will receive an A-record with the value "10.0.0.1," while a user nearer to 48.859741241898114/2.3415648470109653 (the center of Paris) will receive an A-record with the value "10.0.0.2."

The configuration is complete. As soon as you finish creating records, balancing will work.

Balancing by ASN, country, or continent (Geo DNS)

You add metadata of different types to each record. When requesting a domain, a user will receive the record, if its metadata matches the users' characteristics.

You can add the metadata of five types:

asn — autonomous system number,
continents — continent,
countries — country,
fallback — add fallback metadata to the records, that should be sent if the user does not correspond to other metadata,
notes — any comments, this metadata type can be used as a field for notes; for example, you can specify a city, data center name, or a cluster name.

Our system will check if a user matches criteria from the metadata in the following order: ANS, country, continent. The choice of the answer is as follows:

Our DNS server receives a request to the domain.
The DNS server compares the user's ASN with the ASNs from the metadata. If they match, the server sends the record for which the user's ASN matches.
If ASN doesn’t match or is not specified in the metadata, the server compares the user's country with the countries from the metadata. If they match, the server sends the record for which the user's country matches.
If the ASN, and country do not match or are not specified in the metadata, the server compares the user's continent with the continents from the metadata. If they match, the server sends the record for which the user's continent matches.
If the user does not match all the criteria above, then the server sends a record with fallback type metadata.

To start balancing by ASN, country, or continent, select "by non-coordinates meta". Add the required metadata for each record. To add multiple metadata to a single record, click the "+" button on the right. Metadata can be deleted using the "—" button.

Example. A Danish user with ASN 20001 makes a request to testdomain.com. Our DNS server will:

Compare the ASN of the user with the ASN from the metadata. The number is specified for the upper record (123456), it does not match the user’s number (20001), and the upper record is not sent. The same for the lower record.
Compare the user's country with the countries specified in the metadata. The country is specified only for the lower record (Finland), it does not match the user's country (Denmark), and the lower record is not sent.
Compare the user's continent to the continents specified in the metadata. The continent is specified only for the upper record (Europe), it matches the user's continent (Europe). The upper record is sent, and the user goes to the server with IP 10.0.0.1.

8. (Optional) Specify the maximum number of responses

If you use load balancing, fill in the "Max records per response" field. Here, you can specify the maximum number of records of the same type that can be sent to the user in a single response.

An example balancing by ASN/country/continent. As a result of balancing, it turned out that four A-records are suitable for the user at once. If you enter the number "2" in the "Max records per response", our DNS server will send only two A-records. These records will be randomly selected from the four ones that match.

An example balancing by coordinates. Four A-records with different coordinates are available, and the number "2" is specified in the "Max records per response". Our DNS server will send the user two records with the nearest coordinates.

9. Complete the configuration and create resource records

After completing the configuration, click the Create button. DNS records with the specified parameters will be created.

Edit a DNS record

1. Open the record settings as described in step 1 of the instructions above.

2. Click Edit in the menu that appears when you click on the three dots next to the desired resource record or on its name.

3. Make the necessary changes.

4. Click Save or Save and Close to apply the new settings.

Delete a DNS record