Hi,
I am writing a Python 3.4 application that uses Paho as
the MQTT client library. It has been working mostly
fine, but I have now encountered a sudden problem and I
wonder if someone on this list could assist me with it.
I am connecting to a server over ethernet and there is a
company's firewall between my software and the server. It
has worked fine for the 1,5 years I have been doing this
development, except for two occasions, which seem similar
to me. The first time the problem occured, the IT support
was able to fix it in a day by doing something about NAT.
Now the problem came back, and while it looks the same to
me, the IT support hasn't been able to fix it again. There
is a suspect that some router would have been replaced and
that would have altered some settings, but that's just a
guess.
What happens is that when I call Paho's connect(), trying to
bind to a particular IP address (the device has several
network interfaces), connect() just won't return. Ever.
When that happens and I attempt to make sure the ethernet
connection works in general by pinging 8.8.8.8, I get this:
ping -I eth1 8.8.8.8
PING 8.8.8.8 (8.8.8.8) from 82.195.211.99 eth1: 56(84) bytes
of data.
64 bytes from
8.8.8.8:
icmp_seq=1 ttl=52 time=22.5 ms
From
82.195.210.1:
icmp_seq=1 Redirect Host(New nexthop: 82.195.210.2)
From
82.195.210.1:
icmp_seq=2 Redirect Host(New nexthop: 82.195.210.2)
64 bytes from
8.8.8.8:
icmp_seq=2 ttl=52 time=22.8 ms
From
82.195.210.1:
icmp_seq=3 Redirect Host(New nexthop: 82.195.210.2)
64 bytes from
8.8.8.8:
icmp_seq=3 ttl=52 time=25.4 ms
What catches my attention is this: "Redirect Host(New
nexthop: 82.195.210.2)". When everything works fine, that
won't appear. I'm just not enough a network guy to say
anything more. I am just stating what I am seeing.
Just for the sake of comparison, this is what I get when I
ping the same address via a mobile connection that Paho uses
with no problem:
ping -I wwan0 8.8.8.8
PING 8.8.8.8 (8.8.8.8) from 100.88.155.57 wwan0: 56(84) bytes
of data.
64 bytes from
8.8.8.8:
icmp_seq=1 ttl=55 time=883 ms
64 bytes from
8.8.8.8:
icmp_seq=2 ttl=55 time=357 ms
Does anyone have any idea of what might be going on? Is
there something I can do to fix this in how I use Paho? Or is
this something about Paho, and if it is, could it be something
the community might want to fix?
Best Regards,
Antti Gärding
