Network Management
How IPAM gets a MAC Address via SNMP
This article provides information on how IPAM retrieves a MAC Address via SNMP.
First published date
11/29/2018 10:39 PM
Last published date
5/13/2020 7:22 AM
Overview
IPAM obtains MAC addresses via multiple methods, Neighbor scanning (reads the ARP table of the neighboring layer 3 device), DHCP scanning and SNMP poll.
This article provides information on how IPAM gets MAC Address via SNMP poll.
The article can be used to troubleshoot scenarios where IPAM is not displaying a MAC address or when the information presented it not expected.
This article provides information on how IPAM gets MAC Address via SNMP poll.
The article can be used to troubleshoot scenarios where IPAM is not displaying a MAC address or when the information presented it not expected.
Product section
IP Address Manager
Resolution
IPAM polls the following OIDs from the device:
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"
Results are similar to:
In this example we will use 10.199.3.5 & 10.199.5.7 as examples
This OID returns the Interface Index associated with the IP Address .1.3.6.1.2.1.4.20.1.2.10.199.3.5 = INTEGER: 1 .1.3.6.1.2.1.4.20.1.2.10.199.5.7 = INTEGER: 2 This OID returns the physical (MAC) address of the interface indicated above. .1.3.6.1.2.1.2.2.1.6.1 = HEX-STRING: 000F352F4311 .1.3.6.1.2.1.2.2.1.6.2 = HEX-STRING: 000F352F4312
IP 10.199.3.5 -> Interface Index 1 -> MAC 000F352F4311 IP 10.199.5.7 -> Interface Index 2 -> MAC 000F352F4312