connman in dual stack breaks connectivity

connman in dual stack breaks connectivity

[Salvatore Mazzarino]

I’m running connman in dual stack with the following configuration:

      [service_eth0]
      Type=ethernet
      MAC=[hidden]
      IPv4=192.168.159.13/255.255.255.0/192.168.159.1
      IPv6=2001:[hidden]:[hidden]:[hidden]::13/64/2001:[hidden]:[hidden]:1::1
      IPv6.Privacy=enabled
      Nameservers=192.168.159.1,1.1.1.1,2001:470:20::2

The problem is that I cannot ping to the Internet.

Here an example:

worker01 [~]$ ping6 google.com
PING google.com (2a00:1450:4014:80c::200e): 56 data bytes
--- google.com ping statistics ---
2 packets transmitted, 0 packets received, 100% packet loss

Weirdly also IPv4 is broken:

worker01 [~]$ ping google.com
PING google.com (2a00:1450:4014:80c::200e): 56 data bytes

Any other machine (not running connman) in the same IPv4/IPv6 subnets
works fine.

Once I set IPV6=off, IPv4 connectivity gets back again.

Re: connman in dual stack breaks connectivity

[Daniel Wagner]

On Tue, Sep 28, 2021 at 03:31:19PM +0000, Salvatore Mazzarino wrote:
> I’m running connman in dual stack with the following configuration:
> 
>       [service_eth0]
>       Type=ethernet
>       MAC=[hidden]
>       IPv4=192.168.159.13/255.255.255.0/192.168.159.1
>       IPv6=2001:[hidden]:[hidden]:[hidden]::13/64/2001:[hidden]:[hidden]:1::1
>       IPv6.Privacy=enabled
>       Nameservers=192.168.159.1,1.1.1.1,2001:470:20::2
> 
> The problem is that I cannot ping to the Internet.

Unfortunatly, ConnMan's IPv6 implementation depends on the kernel
maintaining the interface and routing table for IPv6. The userspace
stack is missing features. If there is only one interface (e.g. no VPN
etc) things should work but as soon you have more than one interface
things break.It's a pretty messy situation.

> Here an example:
> 
> worker01 [~]$ ping6 google.com
> PING google.com (2a00:1450:4014:80c::200e): 56 data bytes
> --- google.com ping statistics ---
> 2 packets transmitted, 0 packets received, 100% packet loss
> 
> Weirdly also IPv4 is broken:

That is strange indeed. Check the IPv4 routing table if ConnMan screws
it up.

> worker01 [~]$ ping google.com
> PING google.com (2a00:1450:4014:80c::200e): 56 data bytes
> 
> Any other machine (not running connman) in the same IPv4/IPv6 subnets
> works fine.
> 
> Once I set IPV6=off, IPv4 connectivity gets back again.

Yeah, no surprise here :(