The Device List menu displays an overall view of the devices connected to your LAN.

Information is gathered from several sources, including DHCP leases, ARP tables, and WiFi clients.

Interface: shows the interface on which the router sees the device.

Since release 2021.3, this includes physical/logical interface name, and WiFi SSID.

• brX is a bridge representing the LAN.
• ethX is an Ethernet physical interface. This name might be used
  directly, or it might be used indirectly if a bridge/PPP/VPN connection
  is associated with the interface.
• vlanX is a virtual interface, always related to a physical interface.
  For example, in the above example, “vlan2” represents a WAN interface.
• wlX is a (main) wireless radio interface.
  • If you have Virtual Wireless set up, you may have several
    of these, depending on the number of radios in your router.
  • Virtual wireless interfaces are named as wlX.Y .

Devices connected by WiFi appear under the interface name of the SSID to which they are connected.

Device names start at “0”. The first WiFi adapter might be named “wl0”. The second adapter might be “eth1”.

When virtual interfaces are created (secondary SSIDs), additional instances are created.

Media: an icon here represents the interface on which the device is connected, and its connection status.

Interface types include:

• Ethernet
• WiFi (2.4GHz)
• WiFi (5GHz)
• Cellular 3G/4G/5G ISP connection
• PPPoE connection to ISP
• Wireless client (to another router/AP)
• Wireless bridge (to another router/AP)
• PPTP client

WAN interfaces are shown with black and white inverted.

A greyed-out power icon represents a device that is disconnected device or off.

Clicking on the above icon sends a WoL (Wake-on-LAN) packet to the device to wake it up.

For WoL to work, the client also must support it. As well, WoL settings in the BIOS, network adapter and OS may need adjusting.

MAC Address: the hardware address associated with the interface.

• Clicking the MAC address opens a search to identify router vendor,
  based on device OUI (OUI).
  • The OUI is derived from the first 6 digits of its MAC address.
  • This functions only for factory-programmed MAC addresses.
  • It won't work with manually-configured MAC addresses,
    as they can be arbitrarily assigned.

• [DR] stands for the DHCP Reservation feature.
  • This forwards you to the DHCP Reservation menu
    where you can assign a reservation to the MAC address.
  • While there, checking Bound to will enable static ARP mapping
    to the MAC address. This protects against ARP spoofing.

• [BWL] forwards you to the Bandwidth Limiter menu. There, you
  can limit the bandwidth of the device with this MAC address.

• [AR] forwards you to the Access Restriction menu,
  where you can restrict the device's WAN communications.

• [WLF] forwards you to the Wireless Filter menu. There, the device's
  MAC address is prefilled and can be blocked from/allowed
  to connect via WiFi.

IP Address: displays the address linked to the client MAC address.

Unknown addresses aren't shown. This can occur briefly while authenticating, even with WiFi clients with the correct passkey.

Name: the client device's DHCP Hostname.

If no name is shown, the device got a lease from another router, or this router rebooted after the lease was given. A workaround is to add a dhcp-host reference in the dnsmasq Custom Configuration field.

For example, dhcp-host=70:EE:50:37:E8:46,myhostname

This field is also affected by the “Generate a name for DHCP clients which do not otherwise have one” parameter in DHCP/DNS/TFTP.

RSSI: shows Relative Signal Strength.

This applies only to WiFi clients connected to this router. RSSI is measured in negative numbers, with “0” as the best possible value. Thus, -53 is a stronger signal than -74.

Quality: similar to RSSI, but also considers factors like noise floor/interference.

Quality is a better signal assessment.

TX/RX Rate: the current transmit/receive link speed between router/WiFi client.

These fluctuate based on client traffic level and signal quality/distance.

Lease: displays remaining time in the DHCP lease.

Clicking this deletes the lease of a WiFi device and deauthorizes it. When creating static IP reservations, this makes connected devices refresh their previously automatically-assigned address to a new, manually-set one.

Noise floor: indicates the amount of interference affecting each physical radio interface.

Noise, like RSSI, is measured in negative numbers. The best possible value is -100dBm. Any interference will increase the noise value and decrease the Quality.

A strong RSSI and a strong Noise floor on your WiFi may mean your WiFi is unusable. This is usually caused by other WiFi gear transmitting on the same channel. Use the Wireless Survey tool to get more information.

On the 2.4GHz band, common interference sources include:

• Bluetooth devices
• Cordless phones
• Wireless headphones
• Low-quality power supplies
• Microwave ovens

Typically, the 5GHz band has less interference. DFS (Dynamic Frequency Selection) is a common source of interference for certain channels. The DFS function lets 5GHz WiFi use frequencies reserved for radar. Ironically, DFS was designed to reduce interference. DFS interference varies with equipment location. If you suspect DFS interference, see Wikipedia's List of WLAN Channels for details.

Measure: an extra button on certain (mostly MIPS-based) devices to trigger Noise Floor measurement (interference).

For details about noise floor, see the Wireless Survey menu.

Recent versions of this function used to populate the Device List have been refined/offer new features.

Since r2021.4, Network Discovery (v1.7 - 2.0) scan all LAN IP addresses defined in the interface's network/netmask.

R2025.1 and later: include v2.57. This version adds WAN scanning and tweaks to allow better/deeper scanning. Version 2.57 also excludes the addresses of devices already in the scan list, or those with a statically-defined MAC address. These optimize scanning activity.

When enabled, discovery runs continuously and stops when set to “off” or when you leave the Device List page. (Default: off). This requires a global page refresh to have elements appear/disappear automatically in the Device List table.

Version 2.57 also introduces a control for concurrent probes. If discovery is launched while another discovery process is running, the latter discovery is skipped. On the other hand, if discovery happens to be ongoing and a second run is triggered by any change of options, this will instead force a killing of the existing discovery and impose a new execution with the modified parameters.

Sanitize result: clears IP neighbour/ARP table content from spurious information.

Neighbouring devices in a FAILED or INCOMPLETE state are always removed immediately after a scan. However, if this option is enabled, neighbouring devices in a STALE, DELAY or PROBE state also are removed.

This removal is performed after a period defined by (Max Probes * 30ms).

Max Probes: defines how many concurrent probes are allowed at any given time.

If the number rises above the limit, a 250ms delay is used before forking additional probes. A value too high might complete discovery quickly, but might also affect device performance or cause system instability. A low value uses less resources but would delay discovery completion time. The limit is considered globally at system level, not per interface. (Default: 60).

Scan Target: defines on which interfaces devices should be probed.

Options include:

• LANs *
• WANs
• LANs and WANs

Note that these are categories. You cannot select specific interface names.

There is a hardcoded minimum limit of netmask /22 for each interface (or 1022 IP addresses) due to hardware/processing restrictions.

Thus, if a local interface has discovery enabled in the configuration, but the interface's netmask is /21 or less, it is not scanned.

Scan Mode: sets the scanning method used to populate Device List.

• arping - the preferred option for scanning as it's fast and doesn't
  produce spurious neighbour records. This is fine in the great majority of cases.
• traceroute - might occasionally be needed. Some old Apple devices
  appear only when this method is used. However this creates spurious
  device neighbouring records, so the sanitize option is recommended
  when using this method.
• netcat (nc) - as with traceroute, this generates spurious neighbouring entries.
  The sanitize option corrects for this. This is a good alternative method
  when devices otherwise fail to be seen.
• all (round-robin) - alternates sequentially: arping, then traceroute
  and then netcat at each consecutive discovery run.

The unadjustable countdown timer beside Scan Mode indicates how often the scan script is run. It reflects ARP cache aging time, and may vary (say, between ARM and MIPS devices).

The four options above are saved/executed as soon as they're modified (Save is unneeded). The settings are saved in browser cookies and will be remembered by the browser.

Modern WiFi devices may stay connected to WiFi while in sleep mode. Network Discovery will likely detect those devices, but Hostname information may not display until they awaken.

Debugging:

In the remote case when the discovery might not perform as expected it's possible to set manually the NVRAM variable:

nvram set discovery_debug=1

once set the very next discovery call will create some troubleshooting info inside the /tmp/discovery.debug file.

It is recommended to leave this NVRAM variable unset during normal operations.

nvram unset discovery_debug

• A known issues exists, in which a device defined with a static MAC address (DHCP Reservation/Static Arp option) will appear in the list as connected even if it's not connected.