Submit a ticketCall us

Looking to compare latest NPM features with previous versions of NPM?
The NPM new feature summary offers a comparison of new features and improvements offered with this release.

 

Home > Success Center > IP Address Manager (IPAM) > IPAM Administrator Guide > IP Address Monitoring with IPAM > IP Address Conflicts Summary View

IP Address Conflicts Summary View

Created by Nanette.Neal, last modified by Nanette.Neal on Jul 14, 2016

Views: 46 Votes: 0 Revisions: 3

IPAM automatically detects IP conflicts by scanning servers and devices and alerting you when conflicts are found.

How does IPAM detect conflicts?

IPAM primarily looks for differences in MAC addresses, from two distinct simultaneous scans for a single IP Address, within a subnet.

Conflict Scenarios:

SNMP versus SNMP Neighbor: This type of conflict will occur when there is a difference in MAC addresses retrieved from the ARP table of the configured device and SNMP OIDs during the subnet scan for a particular IP Address.

SNMP versus DHCP: This type of conflict will occur when there is a difference in MAC fetched from SNMP OID and DHCP leases from DHCP Server, for a particular IP Address during a subnet scan.

SNMP Neighbor versus DHCP: This type of conflict will occur when there is a difference in MAC addresses retrieved from ARP table of the configured device and DHCP leases from DHCP Server, for a particular IP Address during subnet scan.

DHCP versus DHCP: A range of IP Addresses within a subnet may be managed by two DHCP servers. This type of conflict will occur when there is a difference in MAC addresses retrieved from two DHCP servers lease information for a particular IP Address during subnet scans.

DHCP versus DHCP (Scope Overlap): A range of IP Addresses under a subnet may be managed by two DHCP servers. There are cases wherein a part of an IP Address range under one DHCP server would be managed by another DHCP server. In both instances, there is an overlap in scopes between two DHCP servers. This is considered a conflict

IPAM reservation versus SNMP/DHCP/SNMP neighbor: There are situations where you reserve an IP Address under a subnet in IPAM that contains a MAC address for an internal reference. This type of conflict will occur when there is a difference in MAC addressees from either SNMP OIDs, or DHCP leases, or neighbor devices with reserved MAC addresses in IPAM , for a particular IP Address during a subnet scan.


  • IP conflict occurs from a MAC comparison between snmp > ARP, snmp > snmp (rare), ARP > ARP, snmp > DHCP, ARP > DHCP. IPAM detects conflicts through the following:
    • If there is no DHCP server in your environment that IPAM is scanning, then two machines need to both support SNMP polls so that IPAM sees the MAC address on both devices.
    • If IPAM, during a scan, discovers two machines MAC address with identical IP, IPAM generates an event noting this discovery.
  • During subnet scans, MAC addresses obtained from SNMP, SNMP neighbor, and IPAM reservations are termed as Static entries and those obtained from DHCP servers are termed as Dynamic entries.
  • In all the above cases a generic event along with an alert warning gets displayed under events.
    The generic message would read as  The conflict for IP Address: 10.199.193.66 is detected with MACs: 5C-26-0A-5C-AB-DC, 00-59-07-21-89-1C 
    A warning format would normally read as follows: The IP address 10.199.193.64 is in conflict. The following devices were detected on network with same IP address: - PingSweep* vs Neighbor data MAC: 00-DB-DF-15-B0-03, MAC: 20-CF-30-3A-89-AB
    *Ping sweep is a terminology used to refer SNMP/ICMP data collectively.

Use Case Scenario

In the IP Address Conflicts Summary View you can identify which MAC addresses are sharing the IP and which device first issued the IP.

Active conflicts are identified.

File:Success_Center/New_Articles/IPAM_AdminGuide_MT/040/030/troubleshooting_steps.png

Click on Recommended Actions to for troubleshooting suggestions.

File:Success_Center/New_Articles/IPAM_AdminGuide_MT/040/030/save3.png

Last modified
14:41, 14 Jul 2016

Tags

Classifications

Public