11.5.2 Communication using static NAT

Organization of this subsection

(1) Administering ICMP polling of the management addresses in a static NAT environment
(2) Overview of ICMP polling of the management addresses in a NAT environment

(1) Administering ICMP polling of the management addresses in a static NAT environment

In a NAT environment, a firewall blocks NNMi from communicating with NAT nodes using the IP addresses on the nodes (the private IP addresses). To remedy this, the NAT address (the public IP address) is used for communication with NNMi.

In a NAT environment, a node's management address might be different from the IP addresses hosted on the node. For NNMi to discover a node in a NAT environment, you must add the NAT address to NNMi as a discovery seed. NNMi uses this NAT address for communication, even though it is not in the node's ipAddressTable.

By providing this feature, NNMi avoids false node down incidents and offers a better root cause analysis.

To Page Top

(2) Overview of ICMP polling of the management addresses in a NAT environment

(a) ICMP polling of the management addresses in a NAT environment

Polling of ICMP management addresses of all nodes, including nodes in a NAT environment, is enabled automatically in NNMi. NNMi functions in a NAT environment as explained below.

The Management Address ICMP State field appears in the following forms and table views:
- Node form
- SNMP Agent form
- SNMP Agent table views
NNMi changes the display location of the management address ICMP state, as well as the way it determines the SNMP agent status.

The following table shows the management address ICMP and IP address state polling actions that NNMi takes for ICMP management address polling and ICMP fault polling settings.

Table 11‒1: ICMP configurations and resulting state polling
ICMP management address polling	ICMP fault polling	Management ICMP address state	IP address state
Enabled^#	Disabled^#	Polled^#	Not polled^#
Enabled	Enabled	Polled	Polled
Disabled	Disabled	Not polled	Not polled
Disabled	Enabled	Not polled	Polled

#: Default setting: The table below shows the SNMP agent statuses and the variation in generated incidents, which are determined by APA based on the responses from the SNMP agent and the management address ICMP. With ICMP polling of management addresses enabled, APA considers the management address ICMP response and the SNMP agent response when generating conclusions and incidents.

Table 11‒2: Determining SNMP agent status and generated incidents
SNMP agent response	Management address ICMP response	SNMP agent status	Generated incident
Responding	Responding	Normal	None
Responding	Not responding	Minor	The following incidents might be generated by other network problems: None `AddressNotResponding`
Not responding	Responding	Critical	`SNMPAgentNotResponding`
Not responding	Not responding	Critical	The following incidents might be generated by other network problems: None `NodeDown`

To Page Top