macdedupexceptions.txt — file containing sysObjectId values for types of nodes that are to be considered exceptions to the mac-address-based node deduplication logic
NNMi uses a number of complex algorithms to detect that a node being processed is really a duplicate of another node in the database. In some cases, NNMi compares MAC addresses to try to determine if a node has received a new IP address due to a DHCP lease expiring. This might cause issues with some network devices such as firewalls and loadbalancers. There are some cases where these devices might use common IP addresses and MAC addresses across multiple distinct devices. Normally, NNMi distinguishes between these devices by seeing that the SNMP sysName is different. However, there are also cases where the SNMP sysName can not be made different. In these cases, NNMi might delete one of the devices from the database claiming that it is a duplicate.
For devices such as these loadbalancers and firewalls, NNMi can be told to modify its de-duplication
algorithm by listing these devices' SNMP sysObjectId values in the
macdedupexceptions.txt file.
Devices that are good candidates for inclusion in this file have the following characteristics:
The device must not obtain its IP address from a DHCP server. Its IP address should be statically assigned.
The device must use a unique management IP address.
The following are examples of devices where this configuration file can prove useful:
The device is configured in a redundant configuration with another device that uses some common IP and MAC addresses, and shares a common SNMP sysName.
The device is a physical device that supports several virtual instances, where each instance might be using similar IP and MAC addresses, and sharing a common SNMP sysName.
The file can contain one or more SNMP sysObjectId values, one value per line.
Lines starting with a # are treated as comment lines,
as are blank lines.
Also, a comment can follow a sysObjectId, starting with a # to the end of the line.
White-space in front of or following a sysObjectId is ignored.
And a leading dot (.) on the sysObjectId value is optional.
This file does not exist by default. If it is needed, the NNMi administrator must create it. The file is read by NNMi at startup time. Any changes made after NNMi starts will not be active until NNMi is re-started.
The following is an example of a macdedupexceptions.txt file:
# F5 BIG-IP Pb200 loadbalancer device
.1.3.6.1.4.1.3375.2.1.3.4.19
1.3.6.1.4.1.9.1.1291 #Cisco ACE Service Module