Regex filter for subdomain possible?

dynDNS at dedyn.io
1

is a regex filter for subdomains possible? e.g. there are following subdomains starting with the letter a followed by 3 numbers
a001.example.dedyn.io
a002.example.dedyn.io
…
a999.example.dedyn.io

so can you set a subdomain filter rule like “a*” or “a???” or “a[0-9]+” for such kind of subdomains? if not would it be possible to implement this in your DNS system?

2

Hi noel,

Thanks for your message, and welcome to deSEC! :slight_smile:

What exactly are you referring to (our user interface, the REST API, or something else)?

Stay secure,
Peter

3

yes it concerns rest api calls and if it is possible to set filter for subdomains as described above (not only wildcard *). can you tell me if this is possible, and if not could you implement it in your dns service system?
or can you tell me how many subdomain levels can be used 3 levels or more?
example with 3 levels
lev3.lev2.lev1.example.dedyn.io

4

From a DNS standpoint, you can use as many levels as you fit into the total domain name length of 255 characters. So in theory 127 if every domain part is only a single character.

Desec.io seems to limit the length of a subname to 178 characters, so the most possible subdomains are *.q.r.s.t.u.v.w.x.y.z.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z.on.dedyn.io

5

It is currently not possible to filter like that. Feel free to open a feature request in our issue tracker on GitHub, or contribute an implementation as a pull request. (It is unlikely we would implement this ourselves anytime soon.)

Stay secure,
Peter