ifTable

The objects in ifTable are shown in Figure 1 and listed in Table 1.

Figure 1. Structure of IfTable

Table 1. Description of IfTable objects
Sub-OID	Object	Description
(1)	`Index`	A unique value for each interface. Its value ranges between 1 and the value of `ifNumber`. The value for each interface must remain constant at least from one re-initialization of the entity's network management system to the next re-initialization.
(2)	`Descr`	A textual string containing information about the interface. This string should include the name of the manufacturer, the product name and the version of the hardware interface.
(3)	`Type`	The type of interface, distinguished according to the physical/link protocol(s) immediately ‘below' the network layer in the protocol stack.
(4)	`Mtu`	The size of the largest datagram that can be sent/received on the interface, specified in octets. For interfaces that are used for transmitting network datagrams, this is the size of the largest network datagram that can be sent on the interface.
(5)	`Speed`	An estimate of the interface's current bandwidth in bits per second. For interfaces that do not vary in bandwidth or for those where no accurate estimation can be made, this object should contain the nominal bandwidth.
(6)	`PhysAddress`	The interface's address at the protocol layer immediately `below' the network layer in the protocol stack. For interfaces that do not have such an address (for example, a serial line), this object should contain an octet string of zero length.
(7)	`AdminStatus`	The desired state of the interface. The `testing(3)` state indicates that no operational packets can be passed.
(8)	`OperStatus`	The current operational state of the interface. The `testing(3)` state indicates that no operational packets can be passed.
(9)	`LastChange`	The value of `sysUpTime` at the time the interface entered its current operational state. If the current state was entered prior to the last re- initialization of the local network management subsystem, then this object contains a zero value.
(10)	`InOctets`	The total number of octets received on the interface, including framing characters.
(11)	`InUcastPkts`	The number of subnetwork-unicast packets delivered to a higher-layer protocol.
(12)	`InNUcastPkts`	The number of non-unicast, that is, subnetwork-broadcast or subnetwork-multicast packets delivered to a higher-layer protocol.
(13)	`InDiscards`	The number of inbound packets that were chosen to be discarded even though no errors had been detected to prevent their being deliverable to a higher-layer protocol. One possible reason for discarding such a packet could be to free up buffer space.
(14)	`InErrors`	The number of inbound packets that contained errors preventing them from being deliverable to a higher-layer protocol.
(15)	`InUnknownProtos`	The number of packets received via the interface that were discarded because of an unknown or unsupported protocol.
(16)	`OutOctets`	The total number of octets transmitted out of the interface, including framing characters.
(17)	`OutUcastPkts`	The total number of packets that higher-level protocols requested be transmitted to a subnetwork-unicast address, including those that were discarded or not sent.
(18)	`OutNUcastPkts`	The total number of packets that higher-level protocols requested be transmitted to a non- unicast, that is, a subnetwork-broadcast or subnetwork-multicast address, including those that were discarded or not sent.
(19)	`OutDiscards`	The number of outbound packets that were chosen to be discarded even though no errors had been detected to prevent their being transmitted. One possible reason for discarding such a packet could be to free up buffer space.
(20)	`OutErrors`	The number of outbound packets that could not be transmitted because of errors.
(21)	`OutQLen`	The length of the output packet queue (in packets).
(22)	`Specific`	A reference to MIB definitions specific to the particular media being used to realize the interface. For example, if an Ethernet realizes the interface, then the value of this object refers to a document defining objects specific to Ethernet. If this information is not present, its value should be set to the OBJECT IDENTIFIER {0 0}, which is a syntactically valid object identifier, and any conforming implementation of ASN.1 and BER must be able to generate and recognize this value.