nRF2840: IPv6 over BLE to IPv4 internet via NAT64

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Piotr Szkotak — Mon, 18 Sep 2017 15:01:47 GMT

Indeed, you may need to add another address which is outside of the nat64 64bit long prefix scope.

In case of futher issues I would first check the routing table and then traffic on the bt0, nat64 and the ethernet interface with the tcpdump.

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

BoKarolis — Mon, 18 Sep 2017 14:53:32 GMT

The suggested tayga configuration does not work, if you are using 64:ff9b::/96 prefix, you need to set ipv6 address for tayga.

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Piotr Szkotak — Mon, 18 Sep 2017 14:50:51 GMT

If you receive "no route" error I expect there is missing entry in the routing table. I do not have the proper hardware on my desk at this moment, and I am not sure what exactly did you do. As the starting point I would set tayga.conf to: tun-device nat64 ipv4-addr 192.168.64.1 prefix 64:ff9b::/96 data-dir /var/db/tayga

Then I would clean current tayga database: rm -r /var/db/tayga mkdir -p /var/db/tayga/ touch /var/db/tayga/dynamic.map ip link del dev nat64

Then I would set it back again. tayga --mktun ip link set nat64 up ip addr add 64:ff9b::1 dev nat64 ip addr add 64:ff9b::/64 dev nat64 ip route add 192.168.64.0/24 dev nat64 ip route add 64:ff9b::/64 dev nat64

I would also set bt0 addr and add route to it. ip addr add fdff:cafe:cafe:cafe::/64 dev bt0 ip route add fdff:cafe:cafe:cafe::/64 dev bt0

Kind regards, Piotr Szkotak

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

BoKarolis — Mon, 18 Sep 2017 12:23:53 GMT

Hi, thanks for trying to help. On tcpdump nat64 interface there is nothing received with any of the prefixes. Using 64:ff9b::/96 I cannot even ping myself, as earlier, I am getting a "No route" error. I am not sure what should I set my tayga ipv6 address to, since I can't use 64:ff9b:: prefix for it. I tried 2001:db8:7777::1, but even after adding it to nat64 interface it still does not work.

I have tried with a TI device, and it works with 2004 prefix, hence this shouldn't be the origin of the problem. As I said before, when I add a global ipv6 address to the bt0 interface it should use the global prefix, not the local one. This happens with the TI device, it uses the global address assigned and can communicate even over the internet without problems.

Kind Regards, Karolis

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Piotr Szkotak — Mon, 18 Sep 2017 11:45:40 GMT

Hi Karolis,

I would say that using prefixes like 2003: and 2004: would couse you more trouble in the long run. If it does not work with the 64:ff9b::/96 prefix for tayga it clearly means that there are more issues to solve not that the prefix is incorrect. I would strongly encourage you to stick to 64:ff9b::/96 for NAT64.

Could you look at the tcpdump on the nat64 interface? Do you see packets coming from the bt0?

Kind regards, Piotr Szkotak

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

BoKarolis — Mon, 11 Sep 2017 09:57:36 GMT

Hi, thanks for the answer, however this does not solve the problem. If I set the tayga prefix to 64:ff9b::/96 it asks me to set taygas ipv6 address and then I couldn't manage setting the routing tables correctly to ping myself or anything. Hence I tried setting different prefixes to bt0 and tayga interfaces, as you suggested, 2003:db8:1:ffff::/96 for tayga and 2004:db8:1:ffff::1/64 for bt0. The thing is, that when I look at tcpdump on bt0 interface, the node is using it's local fe80 address to ping google with nat64 prefix. IP6 fe80::282:73ff:fe90:8a48 > 2003:db8:1:ffff::808:808: ICMP6, echo request, seq 2, length 18. And then my bt0 interface replies fe80::ba27:ebff:fea0:1987 > fe80::282:73ff:fe90:8a48 : ICMP6, destination unreachable, beyond scope 2003:db8:1:ffff::808:808, source address fe80::282:73ff:fe90:8a48, length 66

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Piotr Szkotak — Mon, 11 Sep 2017 09:12:03 GMT

Hi Karolis,

It seems that you have selected the same prefix to address your bt network and for tayga to perform IPv6 to IPv4 translation. I would rather use well defined 64:ff9b::/96 prefix for tayga.

Please look at the routing table. The most important entries I would expect to see there are:

64:ff9b::/96 :: U 1024 0 0 nat64

2001:db8::/64 :: U 256 0 0 bt0

According to rfc3849 2001:db8 should serve documentation only, but lets leave it for now.

Please also make sure that you have ipv4 and ipv6 forwarding enabled.

I do not have much experience with tunnels or bridging with BT, so I cannot comment much on that.

Regards, Piotr

Edit: Adding some commands.

tun-device nat64

ipv4-addr 192.168.64.1

prefix 64:ff9b::/96

data-dir /var/db/tayga

Then I would clean current tayga database:

rm -r /var/db/tayga

mkdir -p /var/db/tayga/

touch /var/db/tayga/dynamic.map

ip link del dev nat64

Then I would set it back again.

tayga --mktun

ip link set nat64 up

ip addr add 64:ff9b::1 dev nat64

ip addr add 64:ff9b::/64 dev nat64

ip route add 192.168.64.0/24 dev nat64

ip route add 64:ff9b::/64 dev nat64

I would also set bt0 addr and add route to it.

ip addr add fdff:cafe:cafe:cafe::/64 dev bt0

ip route add fdff:cafe:cafe:cafe::/64 dev bt0

Kind regards, Piotr Szkotak

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

BoKarolis — Fri, 08 Sep 2017 08:00:23 GMT

Hello Piotr, Thank you for the informative comment, I have edited the question with the info you requested. I was monitoring bt0 interface where I can see the packets coming in. In the nat64 interface, nothing is received. Regards, Karolis

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Piotr Szkotak — Thu, 07 Sep 2017 14:41:30 GMT

Hi Karolis,

It seems that you are close to getting it working. Could you share the /etc/tayga.conf, and 'ifconfig' (here we are interested in bt0 and tayga interfaces), 'route -n -A inet6'?

Please hide the sensitive data (especially public/global IPv4 and IPv6 addresses, 'ifconfig' for interfaces other than 'bt0' or tayga interface.

On which interface where you running the tcpdump? You can run it on the tayga interface to see it IPv6 packets from bt0 reach it.

We are successfully used tayga in our Thread Border Router for some time now, you can take a look at the init_nat64() function: github.com/.../thread_border_router

We use non-standard prefix in the following form: prefix_nat48="fd00:0064:0123::" prefix_nat64="fd00:0064:0123:4567::"

Kind regards, Piotr Szkotak

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

BoKarolis — Tue, 05 Sep 2017 12:15:48 GMT

For example, if I need to monitor sensors' data on, say, IBM's quickstart, which is IPv4, I would need to use NAT64 to reach it, right? Could you elaborate and expand on the packet unpacking and the IPv4 tunnel a bit more?

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Petter Myhre — Tue, 05 Sep 2017 12:05:36 GMT

I'm sorry, I don't understand. How would the nodes benefit from reaching a IPv4 network? They only support IPv6. If you don't have IPv6 connectivity, you need to send the IPv6 packets through a IPv4 tunnel to a server that "unpacks" the IPv6 packets relays them to the IPv6 network.

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

BoKarolis — Tue, 05 Sep 2017 11:35:49 GMT

I must have not made myself clear, my aim is to reach IPv4 network, not IPv6.

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Petter Myhre — Tue, 05 Sep 2017 10:56:05 GMT

Ok. I'm not too familiar with Tayga, but I'm pretty sure you need a IPv4 tunnel if you want your IPv6 packets from the nodes to reach a IPv6 network. Doesn't sound like that is what Tayga is doing.

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

BoKarolis — Tue, 05 Sep 2017 07:21:52 GMT

Hi, thank you for the reply, as I said, my ISP does not provide IPv6 addresses, hence I cannot. I am not trying to reach IPv6 internet, I am sure that will be not possible without a tunnel broker. I just need for my node to access IPv4. As the providers will at some point switch to IPv6, I need the nodes to be on IPv6

RE: nRF2840: IPv6 over BLE to IPv4 internet via NAT64

Petter Myhre — Mon, 04 Sep 2017 14:37:36 GMT

Are you able to ping Google's IPv6 address from the RPi?