On Dienstag, 1. November 2016 23:13:45 CET johnzeng wrote: [...]

                         but i have a question ,   there are two 

interface bat0( wlan0 and face HostB) and eth0 ( no batman interface and link to internet ) at hostA

                         echo 1 >/proc/sys/net/ipv4/ip_forward
                         iptables -t nat -A POSTROUTING -o bat0 -j 

MASQUERADE

No, masquerading has to be done on the outgoing interface (towards the next hop which should not see the internal IP addresses - in your example eth0).

Kind regards, Sven