SNMP Configuration and Management Manual

TCP/IP Subagent
SNMP Configuration and Management Manual—424777-006
8-39
ifTable Maintenance
For each subnet found in response to an INFO SPI command for the SUBNET object,
the TCP/IP Subagent extracts the subnet type and the associated I/O process name.
Using this information, the TCP/IP Subagent sends the necessary INFO, STATUS, and
STATISTICS SPI commands for the PORT object.
It then maps the values found in the following structures into the appropriate MIB
objects:
ZTCI-DDL-INFO-SUBNET
ZTCI-DDL-STATS-SUBNET
ZLAM-DDL-STATUS-PORT
ZLAM-DDL-STATS-PORT
ZLAM-DDL-INFO-PORT
If the underlying interface of the subnet is SLSA, the TCP/IP Subagent maps the
values from the following structures:
LMPIFAttr
LMPIFStatus
LMPIFStatistics
If the TCP/IP Subagent finds a change in the subnet configuration while building the
ifTable, it also updates the indexes in the ipAddrTable, ipRouteTable, and
ipNetToMediaTable in the IP group.
The TCP/IP Subagent assigns a number to each SUBNET object defined in the HP
TCP/IP subsystem it is managing. That number represents both the index of the ifTable
and the instance of the MIB object. This number is assigned when an interface is
discovered and never changes while the TCP/IP Subagent executes. However, backup
takeovers can change the assignment of the index value.
When the TCP/IP Subagent finds that a SUBNET object has been deleted or added, it
marks it “deleted” or adds a corresponding ifTable entry. If a SUBNET object is deleted
and then readded with the same attributes, the TCP/IP Subagent removes the
“deleted” mark and reactivates the entry.