DNS server properties dialog - DNS lookup

In this section of the DNS server properties dialog, you specify DNS look up settings for this DNS server:

• Use EDNS0
  Enable this option to allow larger DNS packets over UDP with DNS servers that support this.
  For details on EDNS0 see RFC2671 at http://www.rfc-editor.org/rfc/rfc2671.txt

• Ignore host record TTL value
  Ignore the TTL value when comparing DNS host records retrieved via DNS lookup to the TTL value configured in the Server set properties dialog / DNS data section.

• Perform a DNS lookup to re-check DNS host records every
  Re-check frequency.