Network Management

Hostname and IP columns are not showing in the Port Details UDT widget

Reference this article when the Host Name and IP columns are blank in the port details window.

First published date

10/12/2018 6:14 PM

Last published date

1/6/2025 5:02 PM

Overview

Hostnames and IP addresses are normally visible along with MAC addresses and VLAN numbers in the "port details" window.

In some instances, however, only the port number, MAC, and VLAN columns are visible. The Host Name and IP columns are blank.

Product section

User Device Tracker

Cause

IP address information missing

Resolution

The port details display of the hostname and IP information depends on the device itself, its configuration, and other UDT settings.
There are several things to consider regarding those values:

  • As the information pulled for the ports is Layer 2 information, the general information is what would be seen. If the device also has layer 3 support, then it should also be able to pull the layer 3 information for the ports that have current connections.
  • The UDT node can be set to conduct Layer 2 and Layer 3 polling. You can edit the node in UDT, view Polling and ensure Layer 3 is enabled.

    Polling for layer 3 only works if the device is capable of processing layer 3 requests. Make sure that any monitored layer 3 device in UDT has Layer 3 polling enabled.

  • Ensure the Layer 3 device that is connected to the port of the layer 2 device is added into UDT. If it is not, then UDT would not know to pull this information and combine it with the port details for layer 2.
  • All ARP data is gathering from these two RFC standard OIDs in SNMP: IpNetToMediaTable (1.3.6.1.2.1.4.22) and IpNetToPhysicalTable (1.3.6.1.2.1.4.35). If the device does not support these OIDs, then the ARP data cannot be gathered.
  • If the ARP data is contained within a configured VRF on the device, then you need to add in VRF contexts on the device to allow it to be gathered via SNMP. Refer to Missing IP addresses - ARP contained in VRF.
  • If VLANs are used, there must be proper access to those VLANs.