Changing class precedence
Changing class precedence:
The precedence Kea gives to options in classes is different than other DHCP fields
in classes, such as the "valid-lifetime".
It may be useful to users to allow class-level options to have the same precedence,
as this would give a more flexible usage.
As we need to be most circumspect when introducing this type of change, it has been
suggested that the desired behaviour could indicated by some global setting.
A quick test on Kea 2.5.7 gave the following evaluation results:
For "option_data" defined globally, within a class and within a subnet:
Global: Class: Subnet: Result:
yes no no Global
no yes no Class
no no yes Subnet
yes no yes Subnet
yes yes yes Subnet
yes yes no Class
---- with "only-if-required"
no yes no -
yes yes no Global
yes yes yes Subnet
no yes yes Subnet
---- with "only-if-required" and "require-client-classes"
yes/no yes no Class
yes yes yes Subnet
---- with "require-client-classes"
yes/no yes no Class
yes yes yes Subnet
For "valid-lifetime": defined globally, within a class and within a subnet:
Global: Class: Subnet: Result:
- - - 7200
4000 - - 4000
- 5000 - 5000
- - 6000 6000
- 5000 6000 5000
4000 - 6000 6000
4000 5000 6000 5000
---- with "only-if-required" and "require-client-classes"
4000 7000 - 4000*
4000 7000 6000 6000