show ovsdb tunnels

Syntax

Description

Display the status of tunnels established between Juniper Networks devices that act as hardware virtual tunnel endpoints (VTEPs), and software VTEPs and service nodes that replicate Layer 2 broadcast, unknown unicast, and multicast (BUM) packets within a Virtual Extensible LAN (VXLAN) managed by the Open vSwitch Database (OVSDB) protocol. (In this topic, the software VTEPs and service nodes are known collectively as replicators.)

In this topology with VMware NSX controllers deployed, the hardware VTEP uses the Bidirectional Forwarding Detection (BFD) protocol to monitor replicators learned by the NSX controllers. In this situation, BFD is used to decrease the possibility that BUM packets are forwarded to non-functional replicators and eventually dropped.

To monitor the status of the replicators, the hardware VTEP, replicators, and NSX controllers must all be BFD-capable. (Juniper Networks switches that support OVSDB and VXLAN are BFD-capable.) In addition, the NSX controller must enable BFD on the hardware VTEP and replicators. When the NSX controller has enabled BFD on the hardware VTEP and replicators, their BFD status is considered to be enabled. If the NSX controller cannot enable BFD on these entities (for example, the entity is not BFD-capable), their BFD status is considered to be disabled,

With the BFD protocol enabled on a hardware VTEP, upon receipt of a BUM packet on an OVSDB-managed interface, the hardware VTEP can choose a functional replicator to handle the packet.

In the output of the show ovsdb tunnels command, each tunnel is identified by the IP addresses of the source and destination entities at the ends of the tunnel. Each tunnel that appears is from the perspective of the hardware VTEP. The hardware VTEP provides information about its end of a particular tunnel, while the NSX controller collects the same information from the replicator at the other end of the tunnel. Both hardware VTEP and NSX controller push the information to the tunnel table in the OVSDB schema for physical devices.

Some settings of the BFD Enabled and BFD Status fields in the show ovsdb tunnels output can indicate issues:

A tunnel with a BFD Enabled setting of Enabled and a BFD Status of Down usually indicates that there is an issue with the replicator.
A tunnel with a BFD Enabled setting of Disabled and a BFD Status of AdminDown indicates that either the hardware VTEP, the NSX controller, or the replicator is not BFD-capable or is having an issue with BFD. As a result, a BFD session between the hardware VTEP and the replicator cannot be enabled.

Options

Use one or more of the following options to display a more specific list of tunnels.

none	Display all tunnels.
destination-address `ip-address`(Optional)	Display tunnels that have the specified destination address.
source-address `ip-address`(Optional)	Display tunnels that have the specified source address.

Required Privilege Level

admin

Output Fields

Table 1 lists the output fields for the show ovsdb tunnels command. Output fields are listed in the approximate order in which they appear.

Table 1: show ovsdb tunnels Output Fields
Field Name	Field Descriptions
SRC IP Address	IP address of the OVSDB-managed physical interface from which the BFD control packet is received.
DST IP Address	IP address of the replicator to which the BFD control packet is sent.
BFD Enabled	Status of the BFD protocol on the hardware VTEP and replicator at either ends of the tunnel (`Enabled` or `Disabled`).
BFD Status	Status of a BFD session between a hardware VTEP and a replicator. Possible values include: `Up`—The BFD session is enabled and up. `Down`—The BFD session is considered to be down if a replicator does not respond to three BFD control messages. `AdminDown`—The BFD session is disabled by the NSX controller.