A conceptual row in the alHostTable.
The hlHostControlIndex value in the index identifies the
hlHostControlEntry on whose behalf this entry was created.
The first protocolDirLocalIndex value in the index identifies
the network-layer protocol of the address.
The nlHostAddress value in the index identifies the network-
layer address of this entry.
The second protocolDirLocalIndex value in the index identifies
the protocol that is counted by this entry.
An example of the indexing in this entry is
alHostOutPkts.1.783495.18.4.128.2.6.6.34.
Note that some combinations of index values may result in an
index that exceeds 128 sub-identifiers in length, which exceeds
the maximum for the SNMP protocol. Implementations should take
care to avoid such combinations.