Can't connect MQTT-subscriber to MQTT-broker running on RaspberryPi3

RE: Can't connect MQTT-subscriber to MQTT-broker running on RaspberryPi3

Wolfshund — Tue, 19 Jun 2018 09:23:40 GMT

I feared that.

But many thanks for the help.

I will keep trying. ;)

Best regards,
M. Uhlig

RE: Can't connect MQTT-subscriber to MQTT-broker running on RaspberryPi3

Håkon Alseth — Tue, 19 Jun 2018 09:09:03 GMT

Routing in IPv6 is not an easy topic, as you need to have a lot of knowledge about how both IPv6 works, and how networks work. What you are doing here is that you are making a router for bluetooth IPSP devices, and there is no automated process / script that performs all this for you, so it has to be manually set up.

There's many ways to solve this, but you normally need to match everything up to your own network, and posts from other users might not match your specific setup, so taking their interface names and prefixes directly might give a conflict on your system. My recommendation is to start small, set up things locally on the RPi, then gradually expand piece-by-piece. Save commands that you use to setup the environment in a document or script.

If your prefix is 2002::/64 (which it seems it is at your end), you write: sudo route -A inet6 add 2002::/64 dev bt0.

This should make the interface accessible between other interfaces.

In terms of the broker address set in firmware, this should match your broker address. If you have set up mosquitto on your RPi, it should point to the global IP you have on your eth0 (or wlan0). For simplicity, assign short IPs to your interfaces, like 2002::1, 2002::2 etc.

Cheers,

Håkon

RE: Can't connect MQTT-subscriber to MQTT-broker running on RaspberryPi3

Wolfshund — Tue, 19 Jun 2018 08:40:19 GMT

Hi,

you're right, I set BLE_6LOWPAN_LEGACY_MODE to 0 in the sdk.config

I did not ran "sudo route -A inet6 add <insert prefix>/64 dev bt0". What do I have to use for <insert prefix>?

This brings me to a new question:
Which ip address do I have to enter in the program code for the broker, with the setup from above?

I have no experience with IPv6 over BLE routing and I can not find much information about it. The few instructions in the forums also contradict each other.
So I'm sure there's a misstake in my configuration. The mqtt-subscriber example needs a global IPv6 as broker-address, right?

My broker is running on eth0, and now I see, that my eth0 has no global IPv6 with the current configuration.
But if I assign this to him, what will the 6to4 bring me?

Is there no complete guide to this?

Best regards,
M. Uhlig

RE: Can't connect MQTT-subscriber to MQTT-broker running on RaspberryPi3

Håkon Alseth — Mon, 18 Jun 2018 14:16:36 GMT

Hi,

(int)0xFFFFFFFC = -4, which is:

/** Routing problem. */

ERR_RTE = -4,

Are you running the mqtt broker on the RPi3? If yes, which interface is it binding to? I still suspect this issue is related to the routing on the RPi.

Did you run "sudo route -A inet6 add <insert prefix>/64 dev bt0" ?

Since you are running with a fairly new kernel, did you set sdk_config.h::BLE_6LOWPAN_LEGACY_MODE to '0'? I suspect that you did this, as ping is working. Just need to verify.

Cheers,

Håkon

RE: Can't connect MQTT-subscriber to MQTT-broker running on RaspberryPi3

Wolfshund — Fri, 15 Jun 2018 13:29:48 GMT

I have followed the instructions from your link exactly and still come to the same error. :(

I really hope somebody can help me, because I'm hanging on to the problem for a week and I'm running out of ideas.

Here are all informations about my setup

I'm using the nRF52840-Preview-DK running the example:
SDK\nRF5_SDK_15.0.0_a53641a\examples\iot\mqtt\lwip\subscriber
I only adapted the IPv6-Broker address and changed the output of the error code.

I tried with two versions of Raspbian:

stretch (Linux version 4.14.34-7v+)
jessie (Linux version 4.9.35-v7+)

Both on a Pi 3 Model B with the intern BLE

I'm able to ping the BT device:

root@raspberrypi:/home/pi# ping6 2002::65:24ff:fe54:dc25
PING 2002::65:24ff:fe54:dc25(2002::65:24ff:fe54:dc25) 56 data bytes
64 bytes from 2002::65:24ff:fe54:dc25: icmp_seq=1 ttl=255 time=256 ms
64 bytes from 2002::65:24ff:fe54:dc25: icmp_seq=2 ttl=255 time=182 ms
64 bytes from 2002::65:24ff:fe54:dc25: icmp_seq=3 ttl=255 time=157 ms

My radvd.conf looks like:

interface bt0
{
AdvSendAdvert on;
prefix 2002::/64
{
AdvOnLink off;
AdvAutonomous on;
AdvRouterAddr on;
};
};

route -6 -n shows me:

root@raspberrypi:/home/pi# route -6 -n
Kernel IPv6 routing table
Destination Next Hop Flag Met Ref Use If
::/96 :: Un 256 2 1 6to4
2001::/16 :: U 256 2 5 6to4
2002::/64 :: U 256 2 6 bt0
fe80::/64 :: U 256 1 0 eth0
fe80::/64 :: U 256 1 0 bt0
::/0 ::192.88.99.1 UG 1024 1 0 6to4
::/0 :: !n -1 1 28 lo
::1/128 :: Un 0 6 22 lo
::10.160.8.14/128 :: Un 0 2 0 6to4
2001::/128 :: Un 0 2 0 6to4
2001:aa0:80e::1/128 :: Un 0 2 0 6to4
2002::/128 :: Un 0 2 0 bt0
2002::1/128 :: Un 0 4 7 bt0
fe80::/128 :: Un 0 2 0 eth0
fe80::/128 :: Un 0 2 0 bt0
fe80::b827:ebff:fe36:c0bb/128 :: Un 0 4 2 bt0
fe80::ba27:ebff:fe9c:6a11/128 :: Un 0 2 0 eth0
ff00::/8 :: U 256 4 25 eth0
ff00::/8 :: U 256 1 0 wlan0
ff00::/8 :: U 256 5 34 bt0
ff00::/8 :: U 256 1 0 6to4
::/0 :: !n -1 1 28 lo

ifconfig shows me:

root@raspberrypi:/home/pi# ifconfig
6to4: flags=193<UP,RUNNING,NOARP> mtu 1480
inet6 ::10.160.8.14 prefixlen 96 scopeid 0x80<compat,global>
inet6 2001:aa0:80e::1 prefixlen 16 scopeid 0x0<global>
sit txqueuelen 1000 (IPv6-in-IPv4)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 4 dropped 0 overruns 0 carrier 0 collisions 0

bt0: flags=4161<UP,RUNNING,MULTICAST> mtu 1280
inet6 2002::1 prefixlen 64 scopeid 0x0<global>
inet6 fe80::b827:ebff:fe36:c0bb prefixlen 64 scopeid 0x20<link>
unspec B8-27-EB-36-C0-BB-30-30-00-00-00-00-00-00-00-00 txqueuelen 1000 (UNSPEC)
RX packets 13 bytes 805 (805.0 B)
RX errors 0 dropped 2 overruns 0 frame 0
TX packets 49 bytes 4595 (4.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.160.8.14 netmask 255.255.240.0 broadcast 10.160.15.255
inet6 fe80::ba27:ebff:fe9c:6a11 prefixlen 64 scopeid 0x20<link>
ether b8:27:eb:9c:6a:11 txqueuelen 1000 (Ethernet)
RX packets 71963 bytes 3975733 (3.7 MiB)
RX errors 0 dropped 16 overruns 0 frame 0
TX packets 127886 bytes 188319564 (179.5 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 60 bytes 3000 (2.9 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 60 bytes 3000 (2.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlan0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether b8:27:eb:c9:3f:44 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

root@raspberrypi:/home/pi# service radvd restart
root@raspberrypi:/home/pi# ifconfig
6to4: flags=193<UP,RUNNING,NOARP> mtu 1480
inet6 ::10.160.8.14 prefixlen 96 scopeid 0x80<compat,global>
inet6 2001:aa0:80e::1 prefixlen 16 scopeid 0x0<global>
sit txqueuelen 1000 (IPv6-in-IPv4)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 4 dropped 0 overruns 0 carrier 0 collisions 0

bt0: flags=4161<UP,RUNNING,MULTICAST> mtu 1280
inet6 2002::1 prefixlen 64 scopeid 0x0<global>
inet6 fe80::b827:ebff:fe36:c0bb prefixlen 64 scopeid 0x20<link>
unspec B8-27-EB-36-C0-BB-30-30-00-00-00-00-00-00-00-00 txqueuelen 1000 (UNSPEC)
RX packets 13 bytes 805 (805.0 B)
RX errors 0 dropped 2 overruns 0 frame 0
TX packets 51 bytes 4721 (4.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.160.8.14 netmask 255.255.240.0 broadcast 10.160.15.255
inet6 fe80::ba27:ebff:fe9c:6a11 prefixlen 64 scopeid 0x20<link>
ether b8:27:eb:9c:6a:11 txqueuelen 1000 (Ethernet)
RX packets 72190 bytes 4009629 (3.8 MiB)
RX errors 0 dropped 17 overruns 0 frame 0
TX packets 127918 bytes 188325380 (179.6 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

And the nRF-subscriber tells me:

[00]<info> app: Application started.
<info> app: Physical layer in connectable mode.
<info> app: Physical layer: connected.
<info> app: IPv6 Interface Up.
<info> app: mqtt: error FFFFFFFC

The last line comes from me, as mentioned above.

RE: Can't connect MQTT-subscriber to MQTT-broker running on RaspberryPi3

Håkon Alseth — Fri, 15 Jun 2018 07:24:52 GMT

Hi,

How does your ifconfig and route -6 -n output look? You mention that you are able to ping the BT device, is this on the link-local or the global ip?

In some cases, you might need to restart the radvd service in order to get the routes and global addresses to the bt0 interface.

You can also add the route manually to make your device accessible in a larger network, as discussed here: https://devzone.nordicsemi.com/f/nordic-q-a/5481/making-ipv6-device-available-on-the-internet/19138#19138

Cheers,

Håkon