Overview

Three overlapping-IP-address capabilities are available to the
IP Manager
:
IP address types and definitions
IP address type
Description
Overlapping IP address 1
In a centrally managed configuration in which an ISP manages the private IP networks of different clients, overlapping IP addresses come into existence when the private IP networks employ identically-numbered IP address spaces.
An overlapping IP address may be a management IP address or a non-management IP address.
Management IP address
An IP address that is bound to a device’s SNMP agent.
The
IP Manager
uses a device’s management IP address and ICMP and SNMP polling to discover information about the device and to monitor the device after it is discovered.
Non-management IP address
An IP address that is not bound to a device’s SNMP agent. A non-management IP address is associated with a physical interface of a device.
For a non-management IP address that is part of a discovered device, and assuming that one or more routes exist between the host that is running the
IP Manager
and the non-management IP address, the
IP Manager
will use ICMP polling to monitor the address.
1  Described in detail in the
.
IP tagging feature
Topic
Description
Introduction
IP tagging 1 and IP tag filters enable the
IP Manager
to create IP objects in its modeled topology that represent overlapping IP addresses.
Unmanaged IPs
By default, an IP tag filter sets all IP objects that are created for overlapping IP addresses to “unmanaged.”
Monitoring overlapping IPs
The
IP Manager
monitors the status of the overlapping IP addresses by periodically sending ICMP and SNMP requests to the devices on which the overlapping IP addresses were discovered.
Even for a pair of overlapping IP addresses that are reachable, the
IP Manager
will not be able to monitor them directly because it will not be able to determine which of the devices that are associated with those IP addresses is responding to the ICMP and/or SNMP polls.
1  Described in detail in the
.
Unmanage admin down feature
Topic
Description
Introduction
Unmanage admin down 1 is an alternative to using the IP tagging feature to discover overlapping IP addresses.
When Unmanage admin down is enabled, the
IP Manager
will not discover any IP address that is associated with an administratively down interface.
Purpose
This discovery behavior allows for a situation in which two devices are sharing a management IP address for the following reason:
The currently active device is to be replaced by the administratively down device.
In this situation, the
IP Manager
will discover and create an IP object for the currently active device, but will not discover an IP object for the administratively down device. When the replacement device becomes active, and the currently active device becomes administratively down, the polling will continue.
1  Described in detail in the
.
The IP management domain policy-based or source routing capability enables two or more
IP Manager
s that are running on the same host system to poll
simultaneously
the two or more instances of an overlapping IP address.