Network Management

How are fields in IPAM populated

This article describes how MAC address information, vendor information, and hostname fields are populated in IPAM.

First published date

5/13/2019 5:09 PM

Last published date

12/13/2021 12:56 PM

Overview

Do we know which IPAM fields are populated via DHCP and which are discovered by a SolarWinds query against the machine?

Product section

IP Address Manager

Resolution

MAC address information

There are 3 ways that IPAM can get MAC address information:

  1. Monitor IP Addresses via SNMP [The target device must have SNMP Enabled]
  2. Neighbor Scanning [Scan neighbor layer 3 devices for IP Address to MAC information]
  3. Get the MAC information from DHCP

IPAM polls the following OIDs to get the MAC address:

  • IpAdEntAddr = "1.3.6.1.2.1.4.20.1.1"
  • IpAdEntIfIndex = "1.3.6.1.2.1.4.20.1.2"
  • IfPhysAddress = "1.3.6.1.2.1.2.2.1.6"

Vendor information

Vendor information is gotten from the MAC address. IPAM displays the vendor icons based on the MAC prefix. IPAM supports only MAC prefixes that are listed in the database table "Mac prefixes" in the Orion database.

Manufacturers all place a special number sequence (called the Organizationally Unique Identifier or OUI) in the MAC address that identifies them as the manufacturer.

Hostname

Hostnames are gathered via DNS lookup to the primary DNS server configured on the host server that IPAM is installed on. All the IPs must have a reverse record on that DNS to be able to determine what the hostname is. So if you are missing any hostname entries, check the DNS server to ensure they can be gathered from that server.

We also need to verify that the following record was created on DNS Server.
PTR record is required to resolve IP address (v4/v6) to a hostname.
A record is required to resolve the hostname into an IP address.