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The MAC address table shows which Layer 2 MAC addresses have been learned on which virtual interfaces. While the ARP table maps IP addresses to MAC addresses, the MAC table provides a pure Layer 2 view — confirming that Ethernet frames from remote devices are actually arriving at the Cloud Router and on the correct interface. Use the MAC table to verify physical connectivity, diagnose VLAN or cabling issues, and confirm that devices are reachable at the data link layer.

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View the MAC address table

You can view the MAC address table from Network > Cloud Router > MACs. Each row represents a MAC address that the Cloud Router has learned on a specific interface.
ColumnDescription
MAC AddressThe learned or configured MAC address of the remote device (e.g., 2c:6b:f5:ab:fb:df).
Virtual InterfaceThe Cloud Router interface on which the MAC address was learned (e.g., the name of your port connection, cloud link, or DIA).
PortThe underlying physical port associated with the entry, when applicable.
AgeHow long ago (in minutes) the entry was last seen. An increasing age may indicate that the device has stopped sending traffic.
TypeWhether the entry is Dynamic (learned from incoming Ethernet frames) or Static (manually configured or pinned by the platform).

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Dynamic vs. static entries

  • Dynamic entries are created automatically when the Cloud Router receives an Ethernet frame from a device.

    The Cloud Router records the source MAC address and the interface the frame arrived on. Dynamic entries age out after a period of inactivity — if the device stops sending traffic, the entry will eventually be removed.
  • Static entries are configured manually. Static entries do not age out and persist until they are removed.

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When to use the MAC address table

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Verify device connectivity

After connecting a new device, provisioning a Cloud Router connection, or making cabling changes, check the MAC table to confirm that the remote device’s MAC address appears on the expected virtual interface. A valid MAC entry confirms that the physical link is up and Layer 2 frames are being received.

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Diagnose Layer 2 issues

If a device’s MAC address is missing from the table, the device is either:
  • Not sending traffic (powered off, interface down, or no active sessions).
  • Not connected to the correct port or VLAN.
  • Experiencing a physical link issue (bad cable, incorrect SFP, or port mismatch).
A missing MAC entry points to a problem below Layer 3 — resolve it before investigating routing or BGP.

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Identify unexpected devices

Review the MAC table periodically to ensure that only expected devices are connected to your Cloud Router interfaces. An unfamiliar MAC address may indicate a misconfiguration, a cabling error, or an unauthorized device on the network.

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Correlate with the ARP table

The MAC and ARP tables complement each other:
  • A MAC entry without a corresponding ARP entry means the device is sending Layer 2 frames but has not yet participated in an ARP exchange. This can happen if the device is in a different subnet or has not yet sent IP traffic.
  • An ARP entry without a corresponding MAC entry is unusual and may indicate a stale ARP cache. Refreshing the view or waiting for the next ARP cycle typically resolves this.
  • Both entries present confirms full Layer 2 reachability — the device is physically connected and IP-to-MAC resolution is working.