Creating Wildcard Records in DNS Forwarder/Resolver¶
A wildcard DNS record resolves <anything>.example.com
to a single IP
address, which can be useful in certain cases.
DNS Resolver (Unbound)¶
To create a wildcard entry the DNS Resolver (Unbound), use the following directives in the custom options box:
server:
local-zone: "example.com" redirect
local-data: "example.com 86400 IN A 192.168.1.54"
That makes any host under example.com
resolve to 192.168.1.54
. For
example, www.example.com
, thissitedoesnotexist.example.com
,
mystuff.example.com
, and so on.
DNS Forwarder (dnsmasq)¶
To create a wildcard entry in the DNS Forwarder, use the following directives in the advanced options:
address=/example.com/192.168.1.54
If a specific host override is set for example:
specific.example.com 192.168.1.100
knownhost.example.com 192.168.1.101
Then those would be returned when doing a query for those hosts, only when no specific host has been specified in the host overrides would the advanced wildcard entry be used.
To resolve the domain to an IP address:
example.com 192.168.1.45
Leave the host field blank in the host overrides. So if the query is now for
example.com
the forwarder will return 192.168.1.45
. If a client requests
knownhost.example.com
then 192.168.1.101
would be returned instead.
If a blank hostname example.com
host override entry has not been created,
then a query for example.com
would return the wildcard IP address set in the
advanced option.
If a client queries for madeupname.example.com
then since no specific host
record for madeupname
exists in the host overrides. The forwarder will
return the wildcard entry of 192.168.1.54
.