---

   vtep    ( 5 )

---

Tunnel TABLE

A tunnel created by a Physical_Switch.

Summary: local Physical_Locator remote Physical_Locator Bidirectional Forwarding Detection (BFD): BFD Local Configuration: bfd_config_local : bfd_dst_mac optional string bfd_config_local : bfd_dst_ip optional string BFD Remote Configuration: bfd_config_remote : bfd_dst_mac optional string bfd_config_remote : bfd_dst_ip optional string BFD Parameters: bfd_params : enable optional string, either true or false bfd_params : min_rx optional string, containing an integer, at least 1 bfd_params : min_tx optional string, containing an integer, at least 1 bfd_params : decay_min_rx optional string, containing an integer bfd_params : forwarding_if_rx optional string, either true or false bfd_params : cpath_down optional string, either true or false bfd_params : check_tnl_key optional string, either true or false BFD Status: bfd_status : enabled optional string, either true or false bfd_status : state optional string, one of admin_down, down, init, or up bfd_status : forwarding optional string, either true or false bfd_status : diagnostic optional string bfd_status : remote_state optional string, one of admin_down, down, init, or up bfd_status : remote_diagnostic optional string bfd_status : info optional string

Details: local: Physical_Locator Tunnel end-point local to the physical switch.

remote: Physical_Locator Tunnel end-point remote to the physical switch.

Bidirectional Forwarding Detection (BFD):

BFD, defined in RFC 5880, allows point to point detection of connectivity failures by occasional transmission of BFD control messages. VTEPs are expected to implement BFD.

BFD operates by regularly transmitting BFD control messages at a rate negotiated independently in each direction. Each endpoint specifies the rate at which it expects to receive control messages, and the rate at which it's willing to transmit them. An endpoint which fails to receive BFD control messages for a period of three times the expected reception rate will signal a connectivity fault. In the case of a unidirectional connectivity issue, the system not receiving BFD control messages will signal the problem to its peer in the messages it transmits.

A hardware VTEP is expected to use BFD to determine reachability of devices at the end of the tunnels with which it exchanges data. This can enable the VTEP to choose a functioning service node among a set of service nodes providing high availability. It also enables the NVC to report the health status of tunnels.

In many cases the BFD peer of a hardware VTEP will be an Open vSwitch instance. The Open vSwitch implementation of BFD aims to comply faithfully with the requirements put forth in RFC 5880. Open vSwitch does not implement the optional Authentication or ``Echo Mode'' features.

BFD Local Configuration:

The HSC writes the key-value pairs in the bfd_config_local column to specify the local configurations to be used for BFD sessions on this tunnel.

bfd_config_local : bfd_dst_mac: optional string Set to an Ethernet address in the form xx:xx:xx:xx:xx:xx to set the MAC expected as destination for received BFD packets. The default is 00:23:20:00:00:01.

bfd_config_local : bfd_dst_ip: optional string Set to an IPv4 address to set the IP address that is expected as destination for received BFD packets. The default is 169.254.1.0.

BFD Remote Configuration:

The bfd_config_remote column is the remote counterpart of the bfd_config_local column. The NVC writes the key-value pairs in this column.

bfd_config_remote : bfd_dst_mac: optional string Set to an Ethernet address in the form xx:xx:xx:xx:xx:xx to set the destination MAC to be used for transmitted BFD packets. The default is 00:23:20:00:00:01.

bfd_config_remote : bfd_dst_ip: optional string Set to an IPv4 address to set the IP address used as destination for transmitted BFD packets. The default is 169.254.1.1.

BFD Parameters:

The NVC sets up key-value pairs in the bfd_params column to enable and configure BFD.

bfd_params : enable: optional string, either true or false True to enable BFD on this Tunnel. If not specified, BFD will not be enabled by default.

bfd_params : min_rx: optional string, containing an integer, at least 1 The shortest interval, in milliseconds, at which this BFD session offers to receive BFD control messages. The remote endpoint may choose to send messages at a slower rate. Defaults to 1000.

bfd_params : min_tx: optional string, containing an integer, at least 1 The shortest interval, in milliseconds, at which this BFD session is willing to transmit BFD control messages. Messages will actually be transmitted at a slower rate if the remote endpoint is not willing to receive as quickly as specified. Defaults to 100.

bfd_params : decay_min_rx: optional string, containing an integer An alternate receive interval, in milliseconds, that must be greater than or equal to bfd_params:min_rx. The implementation should switch from bfd_params:min_rx to bfd_params:decay_min_rx when there is no obvious incoming data traffic at the tunnel, to reduce the CPU and bandwidth cost of monitoring an idle tunnel. This feature may be disabled by setting a value of 0. This feature is reset whenever bfd_params:decay_min_rx or bfd_params:min_rx changes.

bfd_params : forwarding_if_rx: optional string, either true or false When true, traffic received on the Tunnel is used to indicate the capability of packet I/O. BFD control packets are still transmitted and received. At least one BFD control packet must be received every 100 * bfd_params:min_rx amount of time. Otherwise, even if traffic is received, the bfd_params:forwarding will be false.

bfd_params : cpath_down: optional string, either true or false Set to true to notify the remote endpoint that traffic should not be forwarded to this system for some reason other than a connectivity failure on the interface being monitored. The typical underlying reason is ``concatenated path down,'' that is, that connectivity beyond the local system is down. Defaults to false.

bfd_params : check_tnl_key: optional string, either true or false Set to true to make BFD accept only control messages with a tunnel key of zero. By default, BFD accepts control messages with any tunnel key.

BFD Status:

The VTEP sets key-value pairs in the bfd_status column to report the status of BFD on this tunnel. When BFD is not enabled, with bfd_params:enable, the HSC clears all key-value pairs from bfd_status.

bfd_status : enabled: optional string, either true or false Set to true if the BFD session has been successfully enabled. Set to false if the VTEP cannot support BFD or has insufficient resources to enable BFD on this tunnel. The NVC will disable the BFD monitoring on the other side of the tunnel once this value is set to false.

bfd_status : state: optional string, one of admin_down, down, init, or up Reports the state of the BFD session. The BFD session is fully healthy and negotiated if UP.

bfd_status : forwarding: optional string, either true or false Reports whether the BFD session believes this Tunnel may be used to forward traffic. Typically this means the local session is signaling UP, and the remote system isn't signaling a problem such as concatenated path down.

bfd_status : diagnostic: optional string A diagnostic code specifying the local system's reason for the last change in session state. The error messages are defined in section 4.1 of [RFC 5880].

bfd_status : remote_state: optional string, one of admin_down, down, init, or up Reports the state of the remote endpoint's BFD session.

bfd_status : remote_diagnostic: optional string A diagnostic code specifying the remote system's reason for the last change in session state. The error messages are defined in section 4.1 of [RFC 5880].

bfd_status : info: optional string A short message providing further information about the BFD status (possibly including reasons why BFD could not be enabled).