Skip to main content
Contributor
October 5, 2007
Question

Port forwarding with secondary IP on wan1

  • October 5, 2007
  • 6 replies
  • 3880 views
Hi, I have made port forwarding with the secondary public IP assigned on WAN1 of FG60 for ports 80 , 25 & 110 to a server on the internal network. The same ports for the same server are forwarded using the WAN1 primary IP address also. From the internet, I' m able to access the server using only the WAN1 primary IP. Both primary and secondary IP are on the same subnet. How can access the server using the secondary IP also? Is this type of config not supported? Regards, Patrick.

    6 replies

    Hracio
    New Member
    October 5, 2007
    Both primary and secondary IP are on the same subnet.
    By default, IP addresses cannot be part of the same subnet. Did you enable overlapping ? (global)# set allow-interface-subnet-overlap enable I will use VIPs instead. Regards,. !!
    Contributor
    October 5, 2007
    Hi, Thanks for the reply. Yes ,I have enabled overlapping. I would prefer VIPs too, but client has other servers also port-forwarded with the secondary IP. Regards, Patrick
    ORIGINAL: Hracio
    Both primary and secondary IP are on the same subnet.
    By default, IP addresses cannot be part of the same subnet. Did you enable overlapping ? (global)# set allow-interface-subnet-overlap enable I will use VIPs instead. Regards,. !!
    UkWizard
    New Member
    October 5, 2007
    Hracio - I suspect he means the second IP from his range, being used via an VIP. NOT an secondary IP on the interface itself. is that correct Benedict Patrick.S? Multiple incoming VIPs are allowed, however just note that only one ext ip can be used when the internal host itself makes an connection.
    Contributor
    October 5, 2007
    Hi, The second IP is configured as secondary IP on the WAN1 interface itself, not a VIP. Regards, Patrick.
    UkWizard
    New Member
    October 5, 2007
    if the ' second' ip you are referring too is in the same ip subnet range, then this is incorrect, you do not need to do that. The only time you use ' secondary' ip function on the physical interfaces is when you have two different ip subnets on the one physical ports (like two ISP connections to the same physical port.) So presuming you are using the one IP subnet, you do not need the secondary ip, so get rid of it. then specify that IP in the VIP and the firewall takes care of the ' magic' :)
    Hracio
    New Member
    October 5, 2007
    but client has other servers also port-forwarded with the secondary IP.
    mm, Is it working that way??? If its the same provider and you are addressing two ips in the same range to wan1 interface.. you are just wasting ip resources.. (or im missing something in the scenario)... Regards,. !
    UkWizard
    New Member
    October 5, 2007
    absolutely. this is exactly why you wouldnt have two external ips in the same range por-forwared to the same server - totally pointless.
    UkWizard
    New Member
    October 5, 2007
    ooops - meant to add :- if you had 5 ip' s off your provider there is no reason why you cannot have all of them natting to the same server. but its pointless except to pacify existing DNS records that may reference different IP' s generally, you assign an external IP to an particular service, like a mail server, or an web server. so that the outbound traffic from that internal server also uses that ext ip, as opposed to the firewalls main IP. like; ip1 - firewall ip2 - mail ip3 - website ip4 - portal the above is a typical setup.
    Contributor
    October 5, 2007
    Hi, The client had some crazy configurations when he had a linux based firewall earlier. I' ve talked the client into reconsidering his IP schemes and now the second IP is NATed to a single critical server running multiple services. The WAN1 interface IP has been used for port forwarding other servers. Issue closed! A second ISP is being configured on WAN2 for link redundancy. Thanks for the good pointers and quick replies. Regards, Patrick.