Match subdomains with a wildcard record

Answer every subdomain that has no record of its own with one Edge DNS wildcard record, from Azion Console, the Azion CLI, or the API.

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You can add a wildcard record to a zone in Edge DNS from Azion Console, the Azion CLI, or the Azion API. The record below answers 192.0.2.31 for every name of example.com that has no record of its own. To answer one named host instead, refer to Add, edit, or delete a record.

Select your interface once. The prerequisites and the procedure below show only that path.

Prerequisites

Add a wildcard record

A record named * answers every name of the zone that has no record of its own, however many labels deep. To answer only the names under one label, such as apps, name the record *.apps instead. Use your own domain wherever this page shows example.com.

To add the wildcard record with the Azion CLI, replace <zone-id> with the ID of your zone. Quote the asterisk so your shell passes it unchanged:

azion create dns-record --zone-id <zone-id> --name "*" --type A --rdata 192.0.2.31 --ttl 3600

The command prints the ID of the record:

Created DNS record with ID 100778

The zone holds the wildcard record. Never include the domain in --name: Edge DNS adds it.

To add the wildcard record with the Azion API, send a POST request to the zone’s records endpoint. Replace <zone-id> with the id of your zone and [TOKEN VALUE] with your personal token:

Shell
01curl -X POST https://api.azion.com/v4/workspace/dns/zones/<zone-id>/records \
02 -H "Authorization: Token [TOKEN VALUE]" \
03 -H "Content-Type: application/json" \
04 -d '{"name":"*","type":"A","rdata":["192.0.2.31"],"ttl":3600}'

A 201 returns the record:

JSON
01{
02 "state": "executed",
03 "data": {
04 "id": 100253,
05 "description": "",
06 "name": "*",
07 "ttl": 3600,
08 "type": "A",
09 "rdata": ["192.0.2.31"],
10 "policy": "simple",
11 "weight": 255
12 }
13}

The zone holds the wildcard record. Never include the domain in name: Edge DNS adds it.

To add the wildcard record in Azion Console:

Open the Edge DNS page

Access Azion Console > Edge DNS.

Open the zone

On the Zones page, select the row of the zone.

Open the Records tab and select + Record

On the Records tab, select + Record. The Create Record drawer opens.

Enter the wildcard name

In Name, enter *. The Console shows your domain after the field and adds it for you, so never type the domain.

Keep the A record type

Keep Record Type set to A - IPv4 Address.

Keep the TTL

Keep TTL (seconds) at 3600.

Enter the value

In Value, enter 192.0.2.31.

Select Save

The Console shows Edge DNS Record has been created, and the * record appears in the Records table.

A name with its own record keeps its own answer: if the zone holds an A record for www, a query for www.example.com returns that record, not 192.0.2.31. For which names a wildcard matches and which it does not, refer to Record types.

Check the answer

Ask Azion’s nameserver directly, without your resolver’s cache, for a name that has no record of its own.

To query ns1.aziondns.net for a name with no record, such as ghost, run:

dig +short @ns1.aziondns.net ghost.example.com A

The nameserver returns the value of the wildcard record:

192.0.2.31

The wildcard answers for ghost.example.com. If the command prints nothing, refer to A new record returns NXDOMAIN.

Next steps

Record typesWhich names a wildcard matches, and which it does not.Add, edit, or delete a recordGive a name its own record, or change the wildcard.Point a subdomain with a CNAME recordSend one subdomain to another host by name.Troubleshoot Edge DNSFix a name that returns NXDOMAIN or a stale answer.