Cisco Aci Bfd

Bidirectional Forwarding Detection (BFD) is a protocol used to rapidly detect failures in the forwarding path between two systems. It can be used with any transport protocol that provides a reliable packet delivery service.

When used in conjunction with a routing protocol, BFD can provide sub-second failure detection times. In a standalone configuration, BFD can provide rapid failure detection for static routes.

BFD for Cisco ACI is supported on all leaf and spine nodes in the Cisco ACI fabric. BFD sessions are established between the APIC and the leaf or spine nodes. A BFD session consists of two unidirectional BFD streams, one in each direction.

The APIC uses BFD to detect the reachability of the leaf and spine nodes. The APIC also uses BFD to detect the health of the interfaces on the leaf and spine nodes. The APIC can detect interface failures such as link down, link flapping, and port shutdown.

BFD for Cisco ACI is configured through the APIC GUI or CLI. BFD sessions are automatically created when a routing protocol or static route is configured. No manual configuration of BFD is required.

BFD for Cisco ACI uses a control plane protocol to exchange BFD control packets between the APIC and the leaf or spine nodes. The data plane protocol is used to exchange BFD data packets between the APIC and the leaf or spine nodes.

The data plane protocol is configurable and can be either IPv4 or IPv6. The control plane protocol is always IPv4.

BFD for Cisco ACI uses UDP port 3784 for the data plane protocol and UDP port 3785 for the control plane protocol.

BFD for Cisco ACI is supported on all Cisco Nexus 9000 Series Switches. BFD for Cisco ACI is also supported on the Cisco Nexus 7000 Series Switches and the Cisco Nexus 6000 Series Switches with the NX-OS 7.0(3)I7(1) release or later.

BFD for Cisco ACI uses a single-hop BFD packet exchange between the APIC and the leaf or spine nodes. BFD for Cisco ACI does not require a multicast group or IP address.

BFD for Cisco ACI requires the use of jumbo frames. A jumbo frame is an Ethernet frame with a frame size greater than 1500 bytes. The maximum frame size supported by BFD for Cisco ACI is 9216 bytes.

BFD for Cisco ACI uses a echo function to verify the reachability of a BFD session. The echo function is disabled by default.

The echo function can be enabled through the APIC GUI or CLI. When the echo function is enabled, the APIC sends BFD echo packets to the leaf or spine nodes at a configurable interval.

The leaf or spine nodes reply to the BFD echo packets. The APIC uses the responses to verify the reachability of the BFD session.

If the APIC does not receive a response to a BFD echo packet, the APIC declares the BFD session to be down.

The echo function can be used to detect failures in the data plane or the control plane.

BFD for Cisco ACI uses a demand mode function to verify the reachability of a BFD session. The demand mode function is disabled by default.

The demand mode function can be enabled through the APIC GUI or CLI. When the demand mode function is enabled, the APIC sends BFD demand packets to the leaf or spine nodes at a configurable interval.

The leaf or spine nodes reply to the BFD demand packets. The APIC uses the responses to verify the reachability of the BFD session.

If the APIC does not receive a response to a BFD demand packet, the APIC declares the BFD session to be down.

The demand mode function can be used to detect failures in the data plane or the control plane.

BFD for Cisco ACI uses a asynchronous mode function to verify the reachability of a BFD session. The asynchronous mode function is disabled by default.

The asynchronous mode function can be enabled through the APIC GUI or CLI. When the asynchronous mode function is enabled, the APIC sends BFD packets to the leaf or spine nodes at a configurable interval.

The leaf or spine nodes reply to the BFD packets asynchron