9. Interfaces¶
The Interfaces dropdown menu entry in the top toolbar contains lists all the interfaces that are currently monitored by ntopng. Among all interfaces listed, one has a check mark that indicates the interface is currently selected. Every data and information shown in ntopng web GUI relates to the currently selected interface. Any interface listed can be selected simply by clicking on its name.

The Interfaces Dropdown Menu
The dropdown menu is only used to switch between selected interfaces, it is also used to actually see interface traffic statistics. Interface traffic statistics can be accessed by clicking on the currently selected interface.

The Home View of the Interface Details Page
A contextual menu with multiple options and badges appear right below the top toolbar. Menu entries are discussed below.
9.1. Home¶
In the Home page it is possible to view general interface information, such as Id (a unique integer identifier ntopng assigns to each monitored interface), family (e.g., pcap), and the overall traffic counters in bytes. It is possible to customise the interface name just by writing a custom name into the Name textbook and clicking on “Save Name”. Interface monitoring can be temporarily paused from the ‘State’ toggle buttons.
9.2. Packets¶
Packets page shows a pie chart of packets size distribution.

The Packets View of the Interface Details Page
9.3. Protocols¶
Protocols page provides three pie charts and a specific table with nDPI-detected protocols for the selected interface.
In the two top pie charts ntopng shows the application distribution and its categorisation. The bottom pie chart shows nDPI-detected applications for currently active flows. All labels are clickable and point to detailed statistics pages. Belo pie charts there is a list of protocols detected with the corresponding total traffic, both in absolute terms and as a percentage of the total traffic. By selecting any Application Protocol, it is possible to display a statistics page with temporal charts for that protocol. Similarly, by clicking on the magnifying lens icon, it is possible to display all active flows for that protocol.

The Protocols View of the Interface Details Page
9.4. ICMP¶
ICMP page shows overall interface ICMP statistics.

The ICMP View of the Interface Details Page
9.5. ARP¶
The Address Resolution Protocol (ARP) page highlights the number of ARP requests and replies seen.

The ARP View of the Interface Details Page
9.6. Statistics¶
Statistics page provides historical traffic statistics for the selected interface. The user can choose to filter statistics on a protocol basis and display data in several formats (e.g., bytes, packets, flows, and so on). In the Professional Version of ntopng, traffic for interface views in shown as stacked per physical interface. Physical interface visualisation can be toggled by clicking on the coloured dot just left of interface name.
The time series span can be adjusted by selecting values from 5 minutes up to 1 year. Moreover, drill- down is possible by clicking on the time series itself. Every click zooms the chart in, centering the time series around the clicked point.
In addition, time series shown can be chosen via the dropdown menu labelled ‘Time series’. For example, it is possible to visualise all or just one protocol, traffic, packets, active hosts and flows, and so on. Ntopng is VLAN aware, hence if several VLANs are detected, traffic is accounted also on a VLAN basis.

The Dropdown Time Series Menu in the Statistics View of the Interface Details Page

The Statistics View of the Interface Details Page (Professional Version)
Historical interface minute top talkers are shown on the right of the page, and get refreshed automatically when the mouse moves over the chart.
An historical “Flows” tab is present next to the “Chart” when ntopng is started with the -F switch. This historical table shows flows data that have been recorded and dumped during the selected observation period. The Professional/Enterprise version of ntopng also feature two extra tabs, namely, “Talkers” and “Protocols” to drill down historical data by talkers and application protocols.

The Historical Flows Table of the Interface Details Page Statistics View
9.7. Traffic Profiles (Professional Version)¶
See later in this manual for more information.
9.8. Settings¶
The settings page allow the configuration of several interface properties.

The Settings View of the Interface Details Page
Custom Name: Is a label used to identify the interface.
Interface Speed: The speed of the interface expressed in Mbps. Typically, ntopng is able to properly determine this speed automatically.
Realtime Stats Refresh Rate: Amount of time between two consecutive refreshes of dashboard and footer charts. Useful for example when using ntopng in combination with nProbe to collect remote NetFlow of sFlow.
Scaling Factor: A constant used to up-scale interface traffic. This is useful when ntopng is processing sampled traffic.
9.9. Host Pools¶
Host pools are logical groups of hosts. Pools are added using the “plus” button in the “Manage Pools” tab of the Host Pools page.

The Edit Host Pools “Manage Pools” of the Interface Details Page
Once an Host Pool is created, it is possible to add members to it. Host Pool members are added using the “plus” button in the “Manage Pool Membership” tab of the Host Pools page.
Each pool member can be a:
- Layer 2 device (specified with a Mac Address)
- Layer 3 host (specified with an IPv4/IPv6 Address and, optionally, a VLAN)
- Layer 3 network (specified with an IPv4/IPv6 network in CIDR format and, optionally, a VLAN)
An “Alias” can be associated to each pool member to ease the its identification. Typically, one would assign a mnemonic label as member alias (e.g., “John’s iPhone” or “Smart TV”). A “Device Type” can be associated to each member as well. Devices types are used to categorise members on the basis of the device type (e.g., TV, Camera, Smartphone).
The image below shows an “IoT Devices” Host Pool with two members, namely a smart tv and a router.

The Edit Host Pools “Manage Pool Membership” of the Interface Details Page
A view of every host pool is accessible from the “Hosts” menu, entry “Host Pools” as discussed earlier in this document. The view shows live pool information (e.g., overall pool throughput) and provides access to the historical pool traffic timeseries (Professional version) as well as to the currently active pool members.
Host pools can also be used to enforce traffic policies (e.g, block YouTube traffic for the “John” pool and limit Facebook traffic at 1 Mbps for the “Guests” pool). This feature is only available when ntopng is used inline and is a feature only available in the professional version. ntopng inline is described in the “Advanced ntopng Features” of this document.