[lwip-users] [lwip] Linux 2.2

[Jason Morgan]

Hi,

I think we are in need of a little help.

As you know we are porting the lwIP to the C166, we've now embarked on IGMP.
In order to speed up development we've adopted
Linux as a test platform for testing.

We're running Redhat 6.2 with the 2.2.x kernel.

We're having trouble getting round that stack structure, in that we ping the
IP address of the tap interface created by lwIP, but
the packets seem to try and go to the wrong adapter.

i.e. tap0 is 192.168.0.2/255.255.255.0 and pinging it causes packets to
arrive at lo (127.0.0.1)

Removing lo results in no ping reply.

Pinging 192.168.0.1 however, does enter the stack as we get
tapif_irq_handler() calls, but never a response.

We are confused as the ip address of the unix ip stack is the same as the ip
address on lwIP, can you send us a model of
how the two stacks co-exist.

Here's how we understand it (obviously wrongly)

We believe that the tap interface installs under the linux IP stack like a
normal ethernet, the lwIP sits on the other
end of a similar adapter connected to the same virtual ethernet, that way
the two stacks are connected internally within a single PC.

We don't see two tap interfaces in ifconfig as one exists in the lwIP domain
and can't be seen from linux.

The other confusion comes from the three applications generated by the
unixsim makefile
simhost
simrouter
simnode

How do these differ?

For the above results (packets on lo) we were running just simhost.

If we run simrouter, we get a message "please run the client" what does that
mean?

Any help or suggestions of what to try next would be appreciated.

Regards,

Jason.


[This message was sent through the lwip discussion list.]