Re: [lwip-users] Connection problem within VM

[Sergio R. Caprile]

What you have is a routing problem.
You have to properly configure your machines (including the virtual one)
to route (or bridge) to the lwIP interface.
Also, lwIP needs to know how to "return" to the other end, you have to
properly configure a default route (or the same subnet) in it.
My setup is something like:
  IP4_ADDR(&gw, 192,168,0,1);
  IP4_ADDR(&ipaddr, 192,168,0,2);
  IP4_ADDR(&netmask, 255,255,255,0);
  netif_add(&netif, &ipaddr, &netmask, &gw, NULL, mintapif_init,
ethernet_input);
  netif_set_default(&netif);

Here, 192.168.0.1 is the address of the 'router' formed by the tun/tap
interface Linux provides for that purposes. As you see, it belongs to
lwIP's subnet and not to the host subnet (my host here is 192.168.69.1)
Your port seems to be working since you say you can access it somehow.
Your virtual machine 'networking adapter' must support routing (or
bridging) too.
I guess you can either route (example) or bridge (all machines and lwIP
on the same subnet), but that depends on your host and virtual machine
capabilities.