Snmp Nat Traversal; Snmp Administrative State Control; Node Maintenance - 3Com V7122 User Manual

If the module on which the GET operation is performed is the second module, then the
values of these two objects are different. If, on the other hand, the module is the first module,
the values of these two objects are the same.

SNMP NAT Traversal

A NAT placed between the gateway and the element manager calls for traversal solutions:
Trap source port: all traps are sent out from the SNMP port (default 161). A manager
receiving these traps can use the binding information (in the UDP layer) to traverse the
NAT back to the device.
The trap destination address (port and IP) are as configured in the snmpTargetMIB.
acKeepAliveTrap: this trap is designed to be a constant life signal from the device to the
manager allowing the manager NAT traversal at all times. The
acBoardTrapGlobalsAdditionalInfo1 varbind has the device's serial number.
The destination port (that is, the manager port for this trap) can be set to be different than
the port to which all other traps are sent. To do this, use the
acSysSNMPKeepAliveTrapPort object in the acSystem MIB or the ini file parameter
KeepAliveTrapPort.
The Trap is instigated in three ways:
Using an ini file parameter (SendKeepAliveTrap = 1). This ensures that the trap is
continuously sent. The frequency is set using the 9/10 of the
acSysSTUNBindingLifeTime object.
After the STUN client has discovered a NAT (any NAT).
If the STUN client cannot contact a STUN server.
The two latter options require the STUN client be enabled (EnableSTUN). Also,
once the acKeepAlive trap is instigated it does not stop.
The manager can view the NAT type in the MIB:
3Com(5003).acProducts(9).acBoardMibs(10).acSystem(10).acSystemStatus(2).
acSysNetwork(6).acSysNAT(2).acSysNATType(1)
The manger also has access to the STUN client configuration:
3Com(5003).acProducts(9).acBoardMibs(10).acSystem(10).acSystemConfiguration(1).a
cSysNetworkConfig(3).acSysNATTraversal(6).acSysSTUN(21)
acNATTraversalAlarm: When the NAT is placed in front a device that is identified as a
symmetric NAT, this alarm is raised. It is cleared when a non-symmetric NAT or no NAT
replace the symmetric one.

SNMP Administrative State Control

Node Maintenance

Node maintenance for the gateway is provided by an SNMP interface. The acBoardMIB
provides two parameters for graceful and forced shutdowns of the gateway:
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V7122 GatewayUser Guide