Typical Uses of Shared Addressing

There are several scenarios where revealing shared addresses is critical to effective WhatsUp Gold monitoring, daily operations, and troubleshooting.

Virtualization.
- Catch cases of misconfiguration due to an administrator or VM deployment application duplicating VNIC addresses (after cloning in vCenter, for example), correct their vCenter instance IDs, and Rescan.
- Detect multiple guest operating systems with virtual network interfaces running on a single physical device.
Proxy. Multiple hosts answering Discovery queries from behind a proxy IP address.
Masquerading.
- Reveal clients (especially from wireless APs) using counterfeit addresses to gain access to your network.
- Reveal clients trying to masquerade using trusted IPs or MAC addresses.
- Intentional masking.
Bridging. Intentional or unintentional bridging or Network Address Translation (NAT) that connects two networks.
IoT Devices. Networked IoT devices such as point of sales kiosks, household devices such as refrigerators, televisions, wireless media, and smart devices can be configured by the manufacturer or reseller to use the same MAC address. Additionally, while in network setup mode (when first unboxed or recently reset, for example), many consumer devices will use the same static IP address.
High Availability networks or sensor arrays. Distributed deployment and architecture patterns on grids (processing or sensor, for example) can use identical addressing for network load balancing between nodes.

Note: Some VPN software clients use a network adapter with a simulated MAC layer and non-unique MAC address. Typically, this addressing is internal at the VPN endpoint and not visible to WhatsUp Gold Discovery.