wlan0 interface fails to fetch IP with udhcpc

I am using USB Wireless Adaptor of Realtek in Android Lollipop with RTL8192DU driver. I am able to scan the wireless network using iwlist wlan0 scan command . And I tried to connect to an open network and fetched the ip using udhcpc ,the output was bit confusing. I got the ip for the wlan0 interface as usual

root@sabresd_6dq:/system/lib/modules # busybox udhcpc -i wlan0               
udhcpc (v1.22.1) started
Sending discover...
Sending select for 192.168.43.206...
Lease of 192.168.43.206 obtained, lease time 3600

But when the checked the netcfg,the wlan0 interface is up with no ip assigned.

root@sabresd_6dq:/system/lib/modules # netcfg
wlan0    UP                                    0.0.0.0/0     0x00001043 
lo       UP                                    127.0.0.1/8   0x00000049 

How is this possible? I have specified the interface while running the udhcpc command since it takes eth0 as default....

When I issue netcfg wlan0 dhcp I am getting the ip also static ip is also working. Why udhcpc is not working...? Any Idea?

I had the same issue. I was able to get the IP with the below command:

netcfg wlan0 dhcp

Go for this command instead of udhcpc -i wlan0.