diff --git a/cns/restserver/ipam_test.go b/cns/restserver/ipam_test.go
index 7220f4d413..495255c5c9 100644
--- a/cns/restserver/ipam_test.go
+++ b/cns/restserver/ipam_test.go
@@ -72,6 +72,10 @@ type ncState struct {
 	ncID string
 	ips  []string
 }
+type endpointState struct {
+	nc     ncState
+	ipInfo map[string]*IPInfo
+}
 
 func getTestService(orchestratorType string) *HTTPRestService {
 	var config common.ServiceConfig
@@ -2154,3 +2158,75 @@ func createAndSaveMockNCRequest(t *testing.T, svc *HTTPRestService, ncID string,
 	require.Equal(t, types.Success, returnCode)
 	require.Empty(t, returnMessage)
 }
+
+func TestStatelessCNIStateFile(t *testing.T) {
+	goodStore := store.NewMockStore("")
+	goodEndpointState := make(map[string]*EndpointInfo)
+	endpointInfo1ContainerID := "0a4917617e15d24dc495e407d8eb5c88e4406e58fa209e4eb75a2c2fb7045eea"
+	endpointInfo1 := &EndpointInfo{PodName: "pod1", PodNamespace: "default", IfnameToIPMap: make(map[string]*IPInfo)}
+	endpointInfo1.IfnameToIPMap["eth0"] = &IPInfo{IPv4: []net.IPNet{{IP: net.IPv4(10, 241, 0, 65), Mask: net.IPv4Mask(255, 255, 255, 0)}}}
+
+	endpointInfo2ContainerID := "1b4917617e15d24dc495e407d8eb5c88e4406e58fa209e4eb75a2c2fb7045eea"
+	endpointInfo2 := &EndpointInfo{PodName: "pod2", PodNamespace: "default", IfnameToIPMap: make(map[string]*IPInfo)}
+	endpointInfo2.IfnameToIPMap["eth2"] = &IPInfo{IPv4: nil, NICType: cns.DelegatedVMNIC, HnsEndpointID: "5c15cccc-830a-4dff-81f3-4b1e55cb7dcb",
+		HnsNetworkID: "5c0712cd-824c-4898-b1c0-2fcb16ede4fb", MacAddress: "7c:1e:52:06:d3:4b"}
+
+	goodEndpointState[endpointInfo1ContainerID] = endpointInfo1
+	err := goodStore.Write(EndpointStoreKey, goodEndpointState)
+	if err != nil {
+		t.Fatalf("Error writing to store: %v", err)
+	}
+	tests := []struct {
+		name       string
+		endpointID string
+		req        map[string]*IPInfo
+		store      store.KeyValueStore
+		want       *EndpointInfo
+		wantErr    bool
+	}{
+		{
+			name:       "good",
+			endpointID: endpointInfo1ContainerID,
+			req:        endpointInfo1.IfnameToIPMap,
+			store:      goodStore,
+			want:       endpointInfo1,
+			wantErr:    false,
+		},
+		{
+			name:       "good with ACI endpoint",
+			endpointID: endpointInfo2ContainerID,
+			req:        endpointInfo2.IfnameToIPMap,
+			store:      goodStore,
+			want:       endpointInfo1,
+			wantErr:    false,
+		},
+		{
+			name:       "endpoint never existed",
+			endpointID: "0a4917617e15d24dc495e407d8eb5c88e4406e58fa209e4eb75a2c2fb7045ee3",
+			req:        endpointInfo2.IfnameToIPMap,
+			store:      goodStore,
+			want:       nil,
+			wantErr:    true,
+		},
+		{
+			name:    "empty store",
+			store:   store.NewMockStore(""),
+			want:    nil,
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			err := svc.UpdateEndpointHelper(tt.endpointID, tt.req)
+			got, err := svc.GetEndpointHelper(tt.endpointID)
+			if tt.wantErr {
+				assert.Error(t, err)
+				return
+			}
+			assert.NoError(t, err)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}