13.5.2 Communication using static NAT
NNMi communicates successfully through a static NAT firewall by automatically applying any available overlapping address mappings to determine the tenant/external IP address pairs for static NAT communications. For details about the benefits, see 13.7 Mapping overlapping IP addresses.
- Organization of this subsection
(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.
(2) Overview of ICMP polling of the management addresses in a NAT environment
(a) ICMP polling of the management addresses in a NAT environment
If you have a NAT environment, we recommend that you do not disable this setting.
To enable ICMP management address polling (if it has been disabled):
From the workspace navigation panel, select the Configuration workspace, expand the Monitoring folder, select Monitoring Configuration, and locate the Default Settings tab.
In the ICMP Fault Monitoring section, select Enable Management Address Polling.
See Set Default Monitoring in NNMi Help.
View the information NNMi displays after performing Actions -> Monitoring Settings for SNMP agents. The displayed information indicates whether management address polling is enabled for NNMi.
When ICMP management address polling is enabled, NNMi changes as follows:
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.
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.
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:
|
Not responding |
Responding |
Critical |
SNMPAgentNotResponding |
Not responding |
Not responding |
Critical |
The following incidents might be generated by other network problems:
|