🚀 go-pugleaf

I am trying to set up a SnapGear SME530 (an embedded linux firewall)
as a router and firewall from an ADSL service (TPG) with a /30 network
address for the router external I/F routing to a public class c
address space on the LAN side. This is shown below:


Internet
 |
 |
 |
 ----ADSL ISP GW address
 | 220.x.y.149/30
 |
 |
 ----ADSL modem in bridge mode RFC1483
 |  admin I/F 203.a.b.253 (currently)
    |
 ----Router/FW (SnapGear SME530)
 +WAN Port-> 220.x.y.150/30 (Ext. Router Port )
  [*]
 +LAN Port-> 203.a.b.1/24 (Int. Router Port )
 |
 |
 |--------------------------------------
    |               |                |
   203.a.b.2     203.a.b.100        etc



From the SME530, I can ping WAN & LAN Interfaces, ISP gateway, any
internet address, LAN hosts.
From the LAN I can only ping the LAN gateway. Can ping other LAN
hosts.
From the Internet I can only ping the router/FW (SME530) WAN
interface.

What do I have to do to get the SME530 to pass traffic (TCP, UDP,
ICMP) from the Internet to servers on the LAN and visa-versa?

I also need to set up firewall rules to restrict traffic to WWW, SMTP,
POP3 from the internet to specific hosts only.

Any config suggests, esp how-to would be greatly appreciated.

Regards & Thank You in advance.
Lazza

P.S. I know the ADSL modem admin I/F should probably be on a private
IP address