Overlay ping and traceroute functionality for VXLAN tunnels

Two new CLI commands supporting ping and traceroute troubleshooting functionality are provided to debug VXLAN overlay tunnels: ping overlay vni vni-id tunnel-src ip-address-src tunnel-dst ip-address-dst and traceroute overlay vni vni-id tunnel-src ip-address-src tunnel-dst ip-address-dst. Use the ping overlay and traceroute overlay commands to validate and verify the presence of the VXLAN tunnel endpoints within the context of the overlay VXLAN Network Identifier or VXLAN Segment ID (VNI) segment.