diff --git a/pkg/cloud/rgraph/rnode/action_update.go b/pkg/cloud/rgraph/rnode/action_update.go
index 5c6e379a..e76fa0f8 100644
--- a/pkg/cloud/rgraph/rnode/action_update.go
+++ b/pkg/cloud/rgraph/rnode/action_update.go
@@ -18,34 +18,120 @@ package rnode
 
 import (
 	"context"
+	"fmt"
+	"time"
 
 	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud"
+	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud/api"
+	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud/meta"
 	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud/rgraph/exec"
 )
 
-// TODO
+func UpdateActions[GA any, Alpha any, Beta any](
+	ops GenericOps[GA, Alpha, Beta],
+	got, want Node,
+	resource api.Resource[GA, Alpha, Beta],
+) ([]exec.Action, error) {
+	preEvents, err := updatePreconditions(got, want)
+	if err != nil {
+		return nil, err
+	}
+	postEvents := postUpdateActionEvents(got, want)
+	return []exec.Action{
+		newGenericUpdateAction(preEvents, ops, want.ID(), resource, postEvents),
+	}, nil
+}
+
+func newGenericUpdateAction[GA any, Alpha any, Beta any](
+	want exec.EventList,
+	ops GenericOps[GA, Alpha, Beta],
+	id *cloud.ResourceID,
+	resource api.Resource[GA, Alpha, Beta],
+	postEvents exec.EventList,
+) *genericUpdateAction[GA, Alpha, Beta] {
+	return &genericUpdateAction[GA, Alpha, Beta]{
+		ActionBase: exec.ActionBase{Want: want},
+		ops:        ops,
+		id:         id,
+		resource:   resource,
+		postEvents: postEvents,
+	}
+}
+
 type genericUpdateAction[GA any, Alpha any, Beta any] struct {
 	exec.ActionBase
+	ops        GenericOps[GA, Alpha, Beta]
+	id         *cloud.ResourceID
+	resource   api.Resource[GA, Alpha, Beta]
+	postEvents exec.EventList
+
+	start, end time.Time
 }
 
 func (a *genericUpdateAction[GA, Alpha, Beta]) Run(
 	ctx context.Context,
 	c cloud.Cloud,
 ) (exec.EventList, error) {
-	return nil, nil
+	a.start = time.Now()
+	err := a.ops.UpdateFuncs(c).Do(ctx, "", a.id, a.resource)
+	a.end = time.Now()
+
+	// Emit DropReference events for removed references.
+	return a.postEvents, err
 }
 
 func (a *genericUpdateAction[GA, Alpha, Beta]) DryRun() exec.EventList {
-	return nil
+	// Emit DropReference events for removed references.
+	return a.postEvents
 }
 
 func (a *genericUpdateAction[GA, Alpha, Beta]) String() string {
-	return "GenericUpdateAction TODO"
+	return fmt.Sprintf("GenericUpdateAction(%v)", a.id)
+}
+
+func (a *genericUpdateAction[GA, Alpha, Beta]) Metadata() *exec.ActionMetadata {
+	return &exec.ActionMetadata{
+		Name:    fmt.Sprintf("GenericUpdateAction(%s)", a.id),
+		Type:    exec.ActionTypeUpdate,
+		Summary: fmt.Sprintf("Update %s", a.id),
+	}
 }
 
-func updatePreconditions(got, want Node) exec.EventList {
+func updatePreconditions(got, want Node) (exec.EventList, error) {
 	// Update can only occur if the resource Exists TODO: is there a case where
 	// the ambient signal for existance from Update op collides with a
 	// reference to it?
-	return nil // TODO: finish me
+	if got.State() != NodeExists || want.State() != NodeExists {
+		return nil, fmt.Errorf("node for update does not exist")
+	}
+
+	outRefs := want.OutRefs()
+	var events exec.EventList
+	// Condition: references must exist before update.
+	for _, ref := range outRefs {
+		events = append(events, exec.NewExistsEvent(ref.To))
+	}
+	return events, nil
+}
+
+func postUpdateActionEvents(got, want Node) exec.EventList {
+	wantOutRefs := want.OutRefs()
+	gotOutRefs := got.OutRefs()
+
+	wantRefs := make(map[meta.Key]struct{})
+	for _, r := range wantOutRefs {
+		var empty struct{}
+		wantRefs[*r.To.Key] = empty
+	}
+
+	// Drop reference for resources that does not exists in want Node.
+	var events exec.EventList
+	for _, wantRef := range gotOutRefs {
+		_, ok := wantRefs[*wantRef.To.Key]
+		if !ok {
+			events = append(events, exec.NewDropRefEvent(wantRef.From, wantRef.To))
+		}
+	}
+
+	return events
 }
diff --git a/pkg/cloud/rgraph/rnode/action_update_test.go b/pkg/cloud/rgraph/rnode/action_update_test.go
new file mode 100644
index 00000000..a5c20f68
--- /dev/null
+++ b/pkg/cloud/rgraph/rnode/action_update_test.go
@@ -0,0 +1,201 @@
+/*
+Copyright 2023 Google LLC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package rnode
+
+import (
+	"testing"
+
+	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud"
+	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud/meta"
+	"github.com/GoogleCloudPlatform/k8s-cloud-provider/pkg/cloud/rgraph/exec"
+)
+
+const project = "proj-id"
+
+func globalID(name string) *cloud.ResourceID {
+	key := meta.GlobalKey(name)
+	return &cloud.ResourceID{
+		Resource:  "node",
+		APIGroup:  "",
+		ProjectID: project,
+		Key:       key,
+	}
+}
+
+func createFakeNode(toRefs []string) Node {
+	fn := fakeNode{}
+	fn.ownership = OwnershipManaged
+	fn.state = NodeExists
+	fn.id = globalID("fn")
+	for _, to := range toRefs {
+		outRef := ResourceRef{
+			From: fn.id,
+			To:   globalID(to),
+		}
+		fn.outRefs = append(fn.outRefs, outRef)
+	}
+	return &fn
+}
+
+func createNotExistingFakeNode() Node {
+	fn := fakeNode{}
+	fn.ownership = OwnershipManaged
+	fn.state = NodeDoesNotExist
+	fn.id = globalID("fn")
+	return &fn
+}
+
+func dropRefEventList(toRefs []string) exec.EventList {
+	var events exec.EventList
+	from := globalID("fn")
+	for _, to := range toRefs {
+		events = append(events, exec.NewDropRefEvent(from, globalID(to)))
+	}
+	return events
+}
+
+func newExistsEventList(toRefs []string) exec.EventList {
+	var events exec.EventList
+	for _, to := range toRefs {
+		events = append(events, exec.NewExistsEvent(globalID(to)))
+	}
+	return events
+}
+
+func TestPostUpdateActions(t *testing.T) {
+	for _, tc := range []struct {
+		desc       string
+		oldNode    Node
+		newNode    Node
+		wantEvents exec.EventList
+		wantErr    bool
+	}{
+		{
+			desc:    "node's without outefs",
+			oldNode: createFakeNode(nil),
+			newNode: createFakeNode(nil),
+		},
+		{
+			desc:       "node's with added outefs",
+			oldNode:    createFakeNode(nil),
+			newNode:    createFakeNode([]string{"a", "b"}),
+			wantEvents: newExistsEventList([]string{"a", "b"}),
+		},
+		{
+			desc:    "node's with deleted outefs",
+			oldNode: createFakeNode([]string{"a", "b"}),
+			newNode: createFakeNode(nil),
+		},
+		{
+			desc:       "node's with replaced outef",
+			oldNode:    createFakeNode([]string{"a", "b"}),
+			newNode:    createFakeNode([]string{"a", "c"}),
+			wantEvents: newExistsEventList([]string{"a", "c"}),
+		},
+		{
+			desc:    "nodes don't exist",
+			oldNode: createNotExistingFakeNode(),
+			newNode: createNotExistingFakeNode(),
+			wantErr: true,
+		},
+		{
+			desc:    "new node doesn't exist",
+			oldNode: createFakeNode([]string{"a", "b"}),
+			newNode: createNotExistingFakeNode(),
+			wantErr: true,
+		},
+	} {
+		t.Run(tc.desc, func(t *testing.T) {
+
+			gotEvents, err := updatePreconditions(tc.oldNode, tc.newNode)
+			gotErr := err != nil
+			if gotErr != tc.wantErr {
+				t.Errorf("updatePreconditions(_, _) = %v, want %v", gotErr, tc.wantErr)
+			}
+			if tc.wantErr {
+				return
+			}
+			if len(gotEvents) != len(tc.wantEvents) {
+				t.Fatalf("event's length mismatch, got: %d, want: %d", len(gotEvents), len(tc.wantEvents))
+			}
+			for i, gotEvent := range gotEvents {
+				wantEvent := tc.wantEvents[i]
+				if !gotEvent.Equal(wantEvent) {
+					t.Errorf("%v != %v", gotEvent.String(), wantEvent.String())
+				}
+			}
+		})
+	}
+}
+
+func TestUpdatePreconditions(t *testing.T) {
+	for _, tc := range []struct {
+		desc       string
+		oldNode    Node
+		newNode    Node
+		wantEvents exec.EventList
+	}{
+		{
+			desc:    "node's without outefs",
+			oldNode: createFakeNode(nil),
+			newNode: createFakeNode(nil),
+		},
+		{
+			desc:    "node's with added outefs",
+			oldNode: createFakeNode(nil),
+			newNode: createFakeNode([]string{"a", "b"}),
+		},
+		{
+			desc:       "node's with deleted outefs",
+			oldNode:    createFakeNode([]string{"a", "b"}),
+			newNode:    createFakeNode(nil),
+			wantEvents: dropRefEventList([]string{"a", "b"}),
+		},
+		{
+			desc:       "node's with deleted first outefs",
+			oldNode:    createFakeNode([]string{"a", "b"}),
+			newNode:    createFakeNode([]string{"b"}),
+			wantEvents: dropRefEventList([]string{"a"}),
+		},
+		{
+			desc:       "node's with deleted outefs, random order",
+			oldNode:    createFakeNode([]string{"a", "b", "c"}),
+			newNode:    createFakeNode([]string{"b", "a"}),
+			wantEvents: dropRefEventList([]string{"c"}),
+		},
+		{
+			desc:       "node's with replaced outefs",
+			oldNode:    createFakeNode([]string{"a", "b", "c"}),
+			newNode:    createFakeNode([]string{"a", "b", "e"}),
+			wantEvents: dropRefEventList([]string{"c"}),
+		},
+	} {
+		t.Run(tc.desc, func(t *testing.T) {
+
+			gotEvents := postUpdateActionEvents(tc.oldNode, tc.newNode)
+			if len(gotEvents) != len(tc.wantEvents) {
+				t.Fatalf("postUpdateActionEvents(got, want) = %d, want %d", len(gotEvents), len(tc.wantEvents))
+			}
+			for i, gotEvent := range gotEvents {
+				wantEvent := tc.wantEvents[i]
+				if !gotEvent.Equal(wantEvent) {
+					t.Errorf("%v != %v", gotEvent.String(), wantEvent.String())
+				}
+			}
+		})
+	}
+}