VPP build used for test: 1.0.0-451~g686a5a5_amd64

It is possible to create VXLAN tunnel over IPv6 interface successfully:
21:16:42.376 DEBUG Executing command in VAT terminal: vxlan_add_del_tunnel src 3ffe:72::10 dst 3ffe:72::20 vni 23
21:16:42.390 DEBUG VAT output:

21:16:42.394 DEBUG [chan 73] EOF sent (73)
21:16:42.394 TRACE Return: 9
21:16:42.394 INFO ${dut1s_vxlan} = 9

but ICMP packet cannot pass through the VXLAN tunnel:
21:16:46.077 TRACE return STDOUT New python executable in env/bin/python
Installing setuptools, pip...done.
Sending packet out of eth3 of len 62
###[ Ethernet ]###
dst = fa:16:3e:29:a6:77
src = fa:16:3e:77:6e:61
type = IPv6
###[ IPv6 ]###
version = 6L
tc = 0L
fl = 0L
plen = 8
nh = ICMPv6
hlim = 64 src = 3ffe:72::1
dst = 3ffe:72::2
###[ ICMPv6 Echo Request ]###
type = Echo Request
code = 0
cksum = 0xfed9
id = 0x0
seq = 0x0
data = ''
21:16:46.077 TRACE return STDERR WARNING: No route found for IPv6 destination :: (no default route?)
sh: 1: cannot create /proc/sys/net/ipv6/conf/eth5/disable_ipv6: Directory nonexistent
sh: 1: cannot create /proc/sys/net/ipv6/conf/eth3/disable_ipv6: Directory nonexistent
Traceback (most recent call last):
File "resources/traffic_scripts/send_ip_icmp.py", line 104, in <module>
main()
File "resources/traffic_scripts/send_ip_icmp.py", line 90, in main
raise RuntimeError('ICMP echo Rx timeout')
RuntimeError: ICMP echo Rx timeout

Output from show trace:
Packet 7
00:00:10:052425: dpdk-input
GigabitEthernet0/4/0 rx queue 0
buffer 0x10f07: current data 0, length 62, free-list 0, totlen-nifb 0, trace 0x6
PKT MBUF: port 0, nb_segs 1, pkt_len 62
buf_len 2176, data_len 62, ol_flags 0x0,
packet_type 0x0
IP6: fa:16:3e:77:6e:61 -> fa:16:3e:29:a6:77
ICMP6: 3ffe:72::1 -> 3ffe:72::2
tos 0x00, flow label 0x0, hop limit 64, payload length 8
ICMP echo_request checksum 0xfed9
00:00:10:052434: ethernet-input
IP6: fa:16:3e:77:6e:61 -> fa:16:3e:29:a6:77
00:00:10:052443: l2-input
l2-input: sw_if_index 5 dst fa:16:3e:29:a6:77 src fa:16:3e:77:6e:61
00:00:10:052445: l2-learn
l2-learn: sw_if_index 5 dst fa:16:3e:29:a6:77 src fa:16:3e:77:6e:61 bd_index 1
00:00:10:052458: l2-fwd
l2-fwd: sw_if_index 5 dst fa:16:3e:29:a6:77 src fa:16:3e:77:6e:61 bd_index 1
00:00:10:052460: l2-flood
l2-flood: sw_if_index 5 dst fa:16:3e:29:a6:77 src fa:16:3e:77:6e:61 bd_index 1
00:00:10:052463: l2-output
l2-output: sw_if_index 9 dst fa:16:3e:29:a6:77 src fa:16:3e:77:6e:61
00:00:10:052482: vxlan-encap
VXLAN-ENCAP: tunnel 0 vni 23
00:00:10:052491: ip6-local
fib 0 adj-idx 8 : local 3ffe:72::10/64 flow hash: 0x00000000
00:00:10:052493: ip6-udp-lookup
UDP: src-port 45571 dst-port 4789
00:00:10:052496: vxlan6-input
VXLAN: no tunnel for vni 23 next 0 error 1
00:00:10:052500: error-drop
vxlan6-input: no such tunnel packets

Log file from the test case is attached.