This object describes 2 attributes of this protocol directory entry.

The presence or absence of the `extensible' bit describes whether or not this protocol directory entry can be extended

by the user by creating protocol directory entries which are children of this protocol.

An example of an entry that will often allow extensibility is `ip.udp'. The probe may automatically populate some children of this node such as `ip.udp.snmp' and `ip.udp.dns'. A probe administrator or user may also populate additional children via remote SNMP requests that create entries in this table. When a child node is added for a protocol for which the probe has no built in support, extending a parent node (for which the probe does have built in support), that child node is not extendible. This is termed `limited extensibility'.

When a child node is added through this extensibility mechanism, the values of protocolDirLocalIndex and protocolDirType shall be assigned by the agent.

The other objects in the entry will be assigned by the manager who is creating the new entry.

This object also describes whether or not this agent can recognize addresses for this protocol, should it be a network level protocol. That is, while a probe may be able to recognize packets of a particular network layer protocol and count them, it takes additional logic to be able to recognize the addresses in this protocol and to populate network layer or application layer tables with the addresses in this protocol. If this bit is set, the agent will recognize network layer addresses for this protoocl and populate the network and application layer host and matrix tables with these protocols.

Note that when an entry is created, the agent will supply values for the bits that match the capabilities of the agent with respect to this protocol. Note that since row creations usually exercise the limited extensibility feature, these bits will usually be set to zero.