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    NAT question, how to NAT internal subnet to another…

    Scheduled Pinned Locked Moved NAT
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    • S
      StefanSander
      last edited by

      hi folks,

      i need a little help with NAT…

      Situation
      i have my LAN on 192.168.0.0/24, the LAN of pfsense is
      on 192.168.0.1. The WAN address of pfsense is 192.168.200.1/24, it's connected
      to a cisco router on 192.168.200.100/24 which does split tunneling for our
      customer network.

      My problem now, our customer sais we have to NAT our
      internal addresses to their 172.17.xxx.xx/29 network
      before they reach the cisco router (split tunneling only works for these
      172.17.xxx.xx /29 subnet addresses i suppose).

      How exactly to do that? Is that possible at all to rewrite (NAT) addresses
      from 192.168.0.0/24 to 172.17.xxx.xxx/29 and send them out on pfsense
      WAN at 192.168.200.1/24 to an cisco which also is on 192.168.200.100?

      I only want to NAT if the target ip is in the subnet of our customer, otherwise
      the address should not be rewritten to be routet to our isp (the cisco does
      ppp). For internet and so on the 192. is ok, just for our customer and
      the split tunneling it has to be 172. (as far as i understood it).

      Is it possible that 1:1 NAT is want i want? Will an IP that is NATed and
      want to connect to the internet instead of our customer be routed
      correctly?

      thanks for reading

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      • H
        hoba
        last edited by

        Not sure how you will send out trtaffic from a 172.17.x.x/29 adress to a gateway at 192.168.200.100/24. This is not possible as the routing won't work.

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        • S
          StefanSander
          last edited by

          yes, exactly that is confusing me on the suggestion of our customer, so you agree
          that this might be a mistake? it's definitly not possible to do that (at least it sounds
          impossible…)?

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          • H
            hoba
            last edited by

            unless the cisco has another additional IP to act as gateway for the 172.x.x.x subnet I don't see how that should work.

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            • S
              StefanSander
              last edited by

              many thanks, i am going to ask if there is a gateway for the 172. subnet.

              Would'nt it be a better solution to route everything normally to the cisco
              router and let it decide on the target ip if it should build up a tunnel or
              send normally via ppp?

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              • H
                hoba
                last edited by

                It somehow sounds to me they are using the 192.ish adresses somewhere already and want/need you to nat to the 172. subnet to not cause conflicts. Hard to say without knowing all the details.

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                • S
                  StefanSander
                  last edited by

                  i will try to get more information from them, maybe they can clear this up.

                  thanks for your help!

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