31.2.4 The internal variables

rX Class mrtObject&
protocols
_ & An array of handles of protocol instances active at the node at which this protocol operates indexed by incoming interface.
mask-wkgroups & Class variable--defines the mask used to identify well known groups.
wkgroups & Class array variable--array of allocated well known groups addresses, indexed by the group name. wkgroups(Allocd) is a special variable indicating the highest currently allocated well known group.

McastProtocol&
status
_ & takes values ``up'' or ``down'', to indicate the status of execution of the protocol instance.
type
_ & contains the type (class name) of protocol executed by this instance, , DM, or ST.

Simulator&
multiSim
_ & 1 if multicast simulation is enabled, 0 otherwise.
MrtHandle
_ & handle to the centralised multicast simulation object.

Node&
switch
_ & handle for classifier that looks at the high bit of the destination address in each packet to determine whether it is a multicast packet (bit = 1) or a unicast packet (bit = 0).
multiclassifier
_ & handle to classifier that performs the s, g, iif match.
replicator
_ & array indexed by s, g of handles that replicate a multicast packet on to the required links.
Agents
_ & array indexed by multicast group of the list of agents at the local node that listen to the specific group.
outLink
_ & Cached list of outgoing interfaces at this node.
inLink
_ & Cached list of incoming interfaces at this node.

Link and SimpleLink&
iif
_ & handle for the NetworkInterface object placed on this link.
head
_ & first object on the link, a no-op connector. However, this object contains the instance variable, link
_, that points to the container Link object.

NetworkInterface&
ifacenum
_ & Class variable--holds the next available interface number.