Peplink Balance IPsec behind firewall

Hi all,

Im new to peplink here.Currently doing a simple setup in office to establish a ipsec vpn between 2 peplink.i able to establish ipsec vpn when both are in same network (siteA : 192.168.3.250 /24& siteB : 192.168.3.254 /24 ).

When i put siteB( ip adress change to 192.168.1.254 /24 ) behind a firewall (192.168.3.254 ) the ipsec vpn goes down. i already port foward UDP : 500,4500, TCP : 32015 but still down. any idea why ?