[lwip-users] Wrong interface when released DHCP-interface available

[Jelinek Robert ETR.ETE3]

I am using lwip with two interfaces: the first one is the ethernet interface, 
the second one is the loopback interface.
 
If the ethernet interface is not initialized by DHCP (at the startup of my 
hardware) oder DHCP releases it bindings, the IP-Netmask is set to 0.0.0.0. 
Then I get a problem: Every traffic to the loopback interface is feed into the 
ethernet interface, because ip_addr_maskcmp inside of ip_route always returns 
true for the ethernet interface in that case. (it works, if I use 
255.255.255.255 for the netmask at the bootup, but it does not solve the 
problem in coorperation with dhcp_release.