How to View GRE Tunnel Statistics

You can use a tunneling mechanism to transport packets of one protocol within another protocol. The protocol that carries the other protocol is called the transport protocol, and the carried protocol is called the passenger protocol. Generic Routing Encapsulation (GRE) is a tunneling mechanism that uses IP as the transport protocol and can carry many different passenger protocols.

The tunnel source address and destination address are used to identify the two endpoints of the virtual point-to-point links in the tunnel.

For more information about configuring GRE tunnels on SD-WAN appliances, see

SD-WAN Center can show you the state of all the GRE tunnels configured in your SD-WAN network.

To view GRE tunnel statistics:

In SD-WAN Center, navigating to Reporting > LAN GRE Tunnels, and in the timeline control select a time period.

For more information about using the timeline control, see How to Use Timeline Controls.

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You can view the following metrics:

  • Worst State: Worst state observed during the selected time period.
  • MTU: Maximum transmission unit —  the size of the largest IP datagram that can be transferred through a specific link.
  • TX Bandwidth: Bandwidth transmitted.
  • RX Bandwidth: Bandwidth received.
  • TX Packets: Number of packets transmitted.
  • RX Packets: Number of packets received.
  • Packets Dropped: Number of packets dropped, because of network congestion.
  • Packets Fragmented: Number of packets fragmented. Packets are fragmented to create smaller packets that can pass through a link with an MTU that is smaller than the original datagram. The fragments are reassembled by the receiving host.
  • Data Coverage:  Percentage of the selected time period for which data is available.


Click the settings icon to select the metrics that you want to view.

How to View GRE Tunnel Statistics