Re: [lwip-users] Assertions when using DHCP when using LWIP 2.0

[Sergio R. Caprile]

Oops...
http://www.nongnu.org/lwip/2_0_0/upgrading.html
  * Changed netif "up" flag handling to be an administrative flag (as 
opposed to the previous meaning of "ip4-address-valid", a netif will now 
not be used for transmission if not up) -> even a DHCP netif has to be 
set "up" before starting the DHCP client

My mistake, you seem to be doing things the right way for 2.0+

Please give details about your port and where did you get the code from.
Try to "manually exercise your code" (debug) to see why you are getting 
those nulls.
Does it happen right on first call or after a while ?

Your mainloop is ... ?
You are not calling lwIP from within the mainloop and interrupts... are 
you ?