MQTT publisher doesn't connect to broker

RE: MQTT publisher doesn't connect to broker

AguirreGENROD — Thu, 13 May 2021 14:08:11 GMT

Hi! Did you find out anything about this? I think I have this same issue. I logged a few things on my own, you can view them on a post I made. From what i recollected, it seems like the connack packet is never sent to BlueZ stack because when capturing from btmon this packet is never shown. It must be related to kernel version because I'm having trouble using a Raspberry Pi 4B with Buster. I have seen a few examples of people using a Jessie kernel and when listing modules related to bluetooth_6lowpan there's no ipv6 module, maybe that has something to do with the problem?

RE: MQTT publisher doesn't connect to broker

PabloAg — Mon, 15 Mar 2021 11:18:11 GMT

Hi, I haven´t

RE: MQTT publisher doesn't connect to broker

Ros — Thu, 11 Mar 2021 08:53:54 GMT

Have you solved the problem?

RE: MQTT publisher doesn't connect to broker

PabloAg — Wed, 27 Jan 2021 12:37:28 GMT

Hi! Yes, i did enable IPv6 forwarding as said here.

RE: MQTT publisher doesn't connect to broker

Ros — Tue, 26 Jan 2021 22:41:25 GMT

Hi,

Did you enable ipv6 forwarding? Tis is required to send global unique addresses, Nevertheless, this is not solved problem at my side.

sudo echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
# OR set ipv6 forwading in /etc/sysctl.conf
# Run radvd daemon.
sudo service radvd restart

I have successfully connected two raspberry pi, using 6lowpan, but cannot send data one to another even-though ping6 works fine at both end. I checked the routing table

route -A inet6

and seems everything fine.

RE: MQTT publisher doesn't connect to broker

Stian Røed Hafskjold — Tue, 26 Jan 2021 21:43:46 GMT

Hi, I tried on this on a RPi too and I see the same thing (your "first behavior"). When I capture packets directly on the bt0 interface I see that the MQTT broker is trying to retransmit the CONNACK, but on the BLE sniffer the packets are never sent from the RPi.

Here is a screenshot of the bt0 interface:

Packet number 7 is the last packet that you can see on the BLE sniffer. It is just an ACK, no data. Then there is another packet (number 8), sent from the broker as well, which has the same sequence number, and same ACK number, but it also contains the CONNACK (4 bytes). Then you can see all the retransmissions of this packet that never arrived.

Since the CONNACK packet is never sent over air, I think there must be something wrong on the RPi side. I will have to investigate further to figure out what is wrong.