Tunnel interface down IPv6 to IPv4 6to4 on S7703

I would like to setup a 6to4 tunnel with a third party software solution and not able. I tried the same settings with other vendors and the solution work except with switch S7703.

The tunnel does not go up and when setting IP address on interface vlan 200, receive error.

<Huawei>display device
S7703's Device status:
Slot  Sub Type     Online   Power   Register     Status     Role
-------------------------------------------------------------------------------
1     -   ES1D2S08SX1E Present   PowerOn   Registered     Normal     NA
2     -   ES1D2S08SX1E Present   PowerOn   Registered     Normal     NA
3     -   ES1D2H02QX2S Present   PowerOn   Registered     Normal     NA
4     -   ES0D00MCUA00 Present   PowerOn   Registered     Normal     Master
5     -   ES0D00MCUA00 Present   PowerOn   Registered     Normal     Slave
PWR1  -   -   Present   PowerOn   Registered     Normal     NA
PWR2  -   -   Present   PowerOn   Registered     Normal     NA
FAN1  -   -   Present   PowerOn   Registered     Normal     NA

After applying command below, error is:

[test-ar1-s7703-Vlanif200] ipv6 address 2001::100/64
Error: The configured IPv6 address conflicted with the IPv6 address or prefix of interface Tunnel94.

1. Checked configuration below:

interface Vlanif200
description IPv6
ipv6 enable

interface Vlanif94
description IPv6 tunnel
ip binding vpn-instance 94
ipv6 enable
ip address 2.2.2.2 255.255.255.252
#
interface Eth-Trunk94
ipv4 statistic enable both
ipv6 statistic enable both
service type tunnel
#
interface GigabitEthernet1/1/6
description ipv4 to RN for IPV6 tunnel
port link-type hybrid
port hybrid tagged vlan 94
loopback-detect enable
#
interface GigabitEthernet2/1/2
description servicee loopback interface
eth-trunk 94
#
interface Tunnel94
description to HE
ip binding vpn-instance 94
ipv6 enable
ipv6 address 2001::2/64
tunnel-protocol ipv6-ipv4 6to4
source 2.2.2.2

eth-trunk 94
#
ipv6 route-static vpn-instance 94 :: 0 Tunnel94
ipv6 route-static vpn-instance 94 2001:: 16 Tunnel94

2. Changed the subnet of VLAN 200 and retried. Displaying interface Tunnel 94 shows tunnel still down:

<Huawei>display intnterface tunnel 94
Tunnel94 current state : UP
Line protocol current state : DOWN
Description:to HE tunnebroker
Route Port,The Maximum Transmit Unit is 1500
Internet protocol processing : disabled
Encapsulation is TUNNEL, loopback not set
Tunnel source 85.11.25.102 (Vlanif94), destination unknown
Tunnel protocol/transport IPv6 over IPv4(6to4)
Current system time: 2017-12-18 14:39
Input bandwidth utilization : --
Output bandwidth utilization : --

3. Tried to configure the tunnel protocol to only ipv6-ipv4 as below, then retried.

#
interface Tunnel94
description to HE
ip binding vpn-instance 94
ipv6 enable
ipv6 address 2002::2/64
tunnel-protocol ipv6-ipv4
source 2.2.2.2

eth-trunk 94

4. Issue solved, interface status became UP!

[Huawei]display intnterface tunnel 94
Tunnel94 current state : UP
Line protocol current state : UP
Description:to HE tunnebroker
Route Port,The Maximum Transmit Unit is 1500
Internet protocol processing : disabled
Encapsulation is TUNNEL, loopback not set
Tunnel source 85.11.25.102 (Vlanif94), destination unknown
Tunnel protocol/transport IPv6 over IPv4(6to4)
Current system time: 2017-12-18 14:39
Input bandwidth utilization : --
Output bandwidth utilization : --