There is any way to allow zone for bridge interface to route zone?
I assume you are running the SRX in mixed mode. So no, the layer two zone policies require layer 2 traffic analysis and the layer 3 zone policies likewise layer 3 analysis.
1.Is possible to route traffic from internal to wan2?
Routing will happen based on the route table and layer 3 information of the packet on the SRX so if traffic arrives to the routing engine it will be routed per the table. But if the traffic arrives as a layer 2 communication it will be switched via the layer 2 data.
Also can irb in layer2 allow traffic to forward to route interface.
Yes, adding an irb interface to a layer 2 domain will create a routing interface for layer 3 requests out of that domain.
Can irb interface provide dhcp services?
Yes dhcp server can be associated with an irb layer 3 interface.
Is configure nat is allow on L2 interface?
No, nat is a layer 3 function
Steve Puluka BSEET - Juniper Ambassador IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP) http://puluka.com/home