# if executable statement construct

# empty configs are not accepted by Kea
default-lease-time 1800;

# if statement
# first true is not recognized even as a boolean expression
if true {  
    option ip-forwarding true;
}

# another
if ( option user-class = "accounting" ) {
    option boot-size 100000;
} elsif option user-class = "engineering" {
    option domain-name "example.com";
}