following its client class or global (or, for option 43, last
resort) definition.
-5. A subnet is chosen, possibly based on the class information when
+5. When the incoming packet belongs the special DROP class it is
+ dropped and an informational message is logged with the packet
+ information.
+
+6. A subnet is chosen, possibly based on the class information when
some subnets are reserved. More precisely: when choosing a subnet,
the server iterates over all of the subnets that are feasible given
the information found in the packet (client address, relay address,
class associated with it, or has a class which matches one of the
packet's classes.
-6. The server looks for host reservations. If an identifier from the
+7. The server looks for host reservations. If an identifier from the
incoming packet matches a host reservation in the subnet or shared
network, the packet is associated with the KNOWN class and all
classes of the host reservation. If a reservation is not found, the
packet is assigned to the UNKNOWN class.
-7. Classes with matching expressions - directly, or indirectly using the
+8. Classes with matching expressions - directly, or indirectly using the
KNOWN/UNKNOWN built-in classes and not marked for later evaluation ("on
request") - are processed in the order they are defined
in the configuration; the boolean expression is evaluated and, if it
class. After a subnet is selected, the server determines whether
there is a reservation for a given client. Therefore, it is not
possible to use KNOWN/UNKNOWN classes to select a shared network or
- a subnet.
+ a subnet, nor to make DROP class dependent of KNOWN/UNKNOWN classes.
-8. If needed, addresses and prefixes from pools are assigned, possibly
+9. If needed, addresses and prefixes from pools are assigned, possibly
based on the class information when some pools are reserved for
class members.
-9. Classes marked as "required" are evaluated in the order in which
+10. Classes marked as "required" are evaluated in the order in which
they are listed: first the shared network, then the subnet, and
finally the pools that assigned resources belong to.
-10. Options are assigned, again possibly based on the class information
+11. Options are assigned, again possibly based on the class information
in the order that classes were associated with the incoming packet.
For DHCPv4 private and code 43 options, this includes class local
option definitions.
The process of classification is conducted in five steps. The first step
is to assess an incoming packet and assign it to zero or more classes.
The second step is to choose a subnet, possibly based on the class
-information. The next step is to evaluate class expressions depending on
+information. When the incoming packet is in the "DROP"
+special class it is dropped and an information message logged.
+The next step is to evaluate class expressions depending on
the built-in "KNOWN"/"UNKNOWN" classes after host reservation lookup,
using them for pool selection and assigning classes from host
reservations. The list of required classes is then built and each class
The process of classification is conducted in five steps. The first step
is to assess an incoming packet and assign it to zero or more classes.
-The second step is to choose a subnet, possibly based on the class information.
+The second step is to choose a subnet, possibly based on the class
+information. When the incoming packet is in the "DROP"
+special class it is dropped and an information message logged.
The next step is to evaluate class expressions depending on the built-in
"KNOWN"/"UNKNOWN" classes after host reservation lookup, using them for
pool/pd-pool selection and assigning classes from host reservations. The