feat: Implement BFD for BGPPeers

api/core/v1alpha1/bfd_types.go

@@ -0,0 +1,41 @@
+// SPDX-FileCopyrightText: 2026 SAP SE or an SAP affiliate company and IronCore contributors
+// SPDX-License-Identifier: Apache-2.0
+
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// BFD defines the Bidirectional Forwarding Detection configuration for interfaces, bgp peerings and static routes.
+type BFD struct {
+	// Enabled indicates whether BFD is enabled on the network object.
+	// +required
+	Enabled bool `json:"enabled"`
+
+	// DesiredMinimumTxInterval is the minimum interval between transmission of BFD control
+	// packets that the operator desires. This value is advertised to the peer.
+	// The actual interval used is the maximum of this value and the remote
+	// required-minimum-receive interval value.
+	// +optional
+	// +kubebuilder:validation:Type=string
+	// +kubebuilder:validation:Pattern="^([0-9]+(\\.[0-9]+)?(ns|us|µs|ms|s|m|h))+$"
+	DesiredMinimumTxInterval *metav1.Duration `json:"desiredMinimumTxInterval,omitempty"`
+
+	// RequiredMinimumReceive is the minimum interval between received BFD control packets
+	// that this system should support. This value is advertised to the remote peer to
+	// indicate the maximum frequency between BFD control packets that is acceptable
+	// to the local system.
+	// +optional
+	// +kubebuilder:validation:Type=string
+	// +kubebuilder:validation:Pattern="^([0-9]+(\\.[0-9]+)?(ns|us|µs|ms|s|m|h))+$"
+	RequiredMinimumReceive *metav1.Duration `json:"requiredMinimumReceive,omitempty"`
+
+	// DetectionMultiplier is the number of packets that must be missed to declare
+	// this session as down. The detection interval for the BFD session is calculated
+	// by multiplying the value of the negotiated transmission interval by this value.
+	// +optional
+	// +kubebuilder:validation:Minimum=1
+	// +kubebuilder:validation:Maximum=255
+	DetectionMultiplier *int32 `json:"detectionMultiplier,omitempty"`
+}

api/core/v1alpha1/bgp_peer_types.go

@@ -64,6 +64,11 @@ type BGPPeerSpec struct {
 	// LocalAS configures the local AS number and how it factors into BGP announcements for this peer.
 	// +optional
 	LocalAS *LocalAS `json:"localAS,omitempty"`
+
+	// BFD defines the Bidirectional Forwarding Detection configuration for the interface.
+	// BFD is only applicable for Layer 3 interfaces.
+	// +optional
+	BFD *BFD `json:"bfd,omitempty"`
 }
 
 // LocalAS defines the local AS configuration and how it factors in BGP announcements.

api/core/v1alpha1/interface_types.go

@@ -266,39 +266,6 @@ type InterfaceIPv4Unnumbered struct {
 	InterfaceRef LocalObjectReference `json:"interfaceRef"`
 }
 
-// BFD defines the Bidirectional Forwarding Detection configuration for an interface.
-type BFD struct {
-	// Enabled indicates whether BFD is enabled on the interface.
-	// +required
-	Enabled bool `json:"enabled"`
-
-	// DesiredMinimumTxInterval is the minimum interval between transmission of BFD control
-	// packets that the operator desires. This value is advertised to the peer.
-	// The actual interval used is the maximum of this value and the remote
-	// required-minimum-receive interval value.
-	// +optional
-	// +kubebuilder:validation:Type=string
-	// +kubebuilder:validation:Pattern="^([0-9]+(\\.[0-9]+)?(ns|us|µs|ms|s|m|h))+$"
-	DesiredMinimumTxInterval *metav1.Duration `json:"desiredMinimumTxInterval,omitempty"`
-
-	// RequiredMinimumReceive is the minimum interval between received BFD control packets
-	// that this system should support. This value is advertised to the remote peer to
-	// indicate the maximum frequency between BFD control packets that is acceptable
-	// to the local system.
-	// +optional
-	// +kubebuilder:validation:Type=string
-	// +kubebuilder:validation:Pattern="^([0-9]+(\\.[0-9]+)?(ns|us|µs|ms|s|m|h))+$"
-	RequiredMinimumReceive *metav1.Duration `json:"requiredMinimumReceive,omitempty"`
-
-	// DetectionMultiplier is the number of packets that must be missed to declare
-	// this session as down. The detection interval for the BFD session is calculated
-	// by multiplying the value of the negotiated transmission interval by this value.
-	// +optional
-	// +kubebuilder:validation:Minimum=1
-	// +kubebuilder:validation:Maximum=255
-	DetectionMultiplier *int32 `json:"detectionMultiplier,omitempty"`
-}
-
 // Ethernet defines the ethernet-specific configuration for physical interfaces.
 type Ethernet struct {
 	// FECMode specifies the Forward Error Correction mode for the interface.

internal/provider/cisco/iosxr/bgp_peer.go

@@ -71,6 +71,12 @@ type BGPPeer struct {
 	Name      string                   `json:"vrf-name"`
 	RD        RouteDistinguisher       `json:"rd,omitzero"`
 	Neighbors NeighborList             `json:"neighbors,omitzero"`
+	BFD       *BFD                     `json:"bfd,omitzero"`
+}
+
+type BFD struct {
+	MinInterval uint32 `json:"minimum-interval,omitempty"`
+	Multiplier  uint32 `json:"multiplier,omitempty"`
 }
 
 // ActivatedAddressFamilies is required for IOS XR to activate the Address-Family under the BGP process

internal/provider/cisco/iosxr/provider.go

@@ -7,10 +7,12 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math"
 	"net"
 	"time"
 
 	"github.com/ironcore-dev/network-operator/api/core/v1alpha1"
+	"github.com/ironcore-dev/network-operator/internal/apistatus"
 	"github.com/ironcore-dev/network-operator/internal/deviceutil"
 	"github.com/ironcore-dev/network-operator/internal/provider"
 	"github.com/ironcore-dev/network-operator/internal/transport/gnmiext"
@@ -477,6 +479,31 @@ func (p *Provider) EnsureBGPPeer(ctx context.Context, req *provider.EnsureBGPPee
 		RD:       rd,
 	}
 
+	if req.BGPPeer.Spec.BFD != nil && req.BGPPeer.Spec.BFD.Enabled {
+		bfd := &BFD{}
+		if req.BGPPeer.Spec.BFD.RequiredMinimumReceive != nil {
+			ms := req.BGPPeer.Spec.BFD.RequiredMinimumReceive.Duration
+			if ms < 0 || ms > math.MaxUint32 {
+				return apistatus.NewInvalidArgumentError(apistatus.FieldViolation{
+					Field:       "spec.bfd.requiredMinimumReceive",
+					Description: "BFD minimum receive interval must be between 0ms and 4294967295ms",
+				})
+			}
+			bfd.MinInterval = uint32(ms)
+		}
+		if req.BGPPeer.Spec.BFD.DetectionMultiplier != nil {
+			multiplier := *req.BGPPeer.Spec.BFD.DetectionMultiplier
+			if multiplier < 0 {
+				return apistatus.NewInvalidArgumentError(apistatus.FieldViolation{
+					Field:       "spec.bfd.detectionMultiplier",
+					Description: "BFD detection multiplier must be non-negative",
+				})
+			}
+			bfd.Multiplier = uint32(multiplier)
+		}
+		peer.BFD = bfd
+	}
+
 	if req.BGPPeer.Spec.AddressFamilies != nil && (req.BGPPeer.Spec.AddressFamilies.Ipv6Unicast != nil || req.BGPPeer.Spec.AddressFamilies.L2vpnEvpn != nil) {
 		return errors.New("bgp peer: ipv6 unicast or l2vpnEvpn address family is currently not supported")
 	}