linux VERSION="14.04.4 LTS, Trusty Tahr"

vpp# sh version verbose
Version: v16.09-rc0~45-g16c75df
Compiled by: vagrant
Compile host: localhost
Compile date: Thu Jun 2 01:57:45 PDT 2016
Compile location: /home/vagrant/vpp
Compiler: GCC 4.8.4
CPU model name: Intel(R) Core(TM) i7-3740QM CPU @ 2.70GHz
CPU microarchitecture: IvyBridge (IvyBridge)
CPU flags: sse3 ssse3 sse41 sse42 avx aes
Current PID: 1103
DPDK Version: DPDK 16.04.0
DPDK EAL init args: -c 1 -n 4 --huge-dir /run/vpp/hugepages --file-prefix vpp -b 0000:00:03.0 -b 0000:00:09.0 --master-lcore 0 --socket-mem 512

i'm adding tunnel through vat terminal:
vagrant@localhost:~$ sudo vpp_api_test
vat# vxlan_add_del_tunnel src 172.16.0.1 dst 172.16.0.2 vni 24

when i checking it, there some ipv6 format address:
vat# vxlan_tunnel_dump
sw_if_index src_address dst_address encap_vrf_id decap_next_index vni
6 ac10:1:: ac10:2:: 0 1 24

but when i checking it with json output, it is ok:
vagrant@localhost:~$ sudo vpp_api_test json
vat# vxlan_tunnel_dump

[

{ "sw_if_index": 6, "src_address": "172.16.0.1", "dst_address": "172.16.0.2", "encap_vrf_id": 0, "decap_next_index": 1, "vni": 24, "is_ipv6": 0 }

]