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I am trying to configure this Yamaha router in our lab to open ports to access GMAIL (smtp/imap).I understood that I have to open ports 995 and 465 for this.

Should I do this in "Packet Filtering" or in "NAT" ?

The following images show my current Packet Filtering settings for WAN. (Note that this router's interface is in Japanese and I have shown Google Translated pages)

  • "Packet Filtering" settings for IN-bound connections to WAN.

    enter image description here

  • "Packet Filtering" settings for OUT-bound connections to WAN.

    enter image description here

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migrated from Apr 7 '11 at 3:32

This question came from our site for system and network administrators.

up vote 0 down vote accepted

Packet Filtering and Address Translation are two different concepts. If you have just one public address you will need to use both, in both directions to achieve your goals.

For inbound, you will need an address translation rule that translates the destination IP and port of the incoming packet from the outside (WAN) address to the inside (private) address. You will then need a packet filtering rule that permits this traffic.

For outbound, you will need what is called a "source NAT" rule, which may already be on by default that automatically translates all outbound packets to appear as if they are coming from the IP address of the WAN interface. You should also have corresponding packet filtering rules that allow out the ports you wish to be able to access the WAN connection.

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