Fwd: ddns-updates off; within pool doesn't work

[Alexei V. Schukin]

Hi, everyone!

I have a question about dynamic dns updates in dhcp.
I'm trying to exclude one pool of subnet from dynamic updates.

This is a part from my dhcpd.conf:

---
ddns-update-style interim;
ddns-updates on;
update-static-leases on;
allow-unknown clients;
...

subnet 192.168.0.1 netmask 255.255.255.0 {
  pool {
    range 192.168.0.10 192.168.0.20;
    deny unknown-clients;
    ddns-updates off;
    ignore client-updates;
  }

  range dynamic-bootp 192.168.0.21 192.168.0.254;
  allow clients-updates;
  ...
}
---

But it doesn't work: dhcpd still updating dns within this address pool.
What I'm missing?

isc-dhcpd-4.1.1-P1

P.S.: Sorry if this is a duplicate message.

--
Thanks,
Alex