ping from VM instance to router interface failed

unable to ping router interface from VM instance.

step to reproduce the issue:

1. Create Network
openstack network create l2_network_1 --provider-network-type vxlan

openstack subnet create --network l2_network_1 --subnet-range 30.0.0.0/24 l2_subnet_1

2. Create VM
openstack server create --image <imageID> --flavor m1.tiny --nic net-id=l2_network_1 VM1 --security-group default

3. Create Router
openstack router create router1

Attaching Interfaces to router,
openstack router add subnet router1 l2_subnet_1

4.Ping from VM to router interface.

step 4 failed