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    NAT of whole subnet

    Scheduled Pinned Locked Moved NAT
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    • S
      smoores
      last edited by

      @Derelict:

      Just route 10.16.16.0/20 from the ASA to the captive portal unit and disable NAT on pfSense. There is zero reason to NAT on the inside like that.

      Generally: disable outbound NAT on WAN for source 10.16.16.0/20.

      So your suggesting that the LAN and WAN interface would have different IP addresses on the same subnet? e.g. perhaps LAN is 10.16.16.1, WAN is 10.16.16.2 and the Firewall is 10.16.16.3 and then hand out 10.16.16.4 - 10.16.31.254 in the DHCP scope?

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      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by

        No that is not what he is suggesting..

        The wan of pfsense would be a transit network if there is an upstream router/firewall.. Ie your ASA..  So you would have something like this

        internet - publicIP asa 172.16.0.1 – transit 172.16.0/30 --- 172.16.0.2/30 pfsense 10.0.0.1/20 -- devices on 10.0.0/20

        But I personally would just have multiple segments behind pfsense.. so your not using such a large broadcast domain..  Guess the one advantage to using such a large segment for your clients is if you had clients jumping from AP to AP that were on different segments you could run into some dhcp issues..

        But there really is no reason to nat between your transit network and your clients at pfsense.

        Your asa is what would nat your 10 addresses to your public.

        An intelligent man is sometimes forced to be drunk to spend time with his fools
        If you get confused: Listen to the Music Play
        Please don't Chat/PM me for help, unless mod related
        SG-4860 24.11 | Lab VMs 2.8, 24.11

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        • S
          smoores
          last edited by

          @johnpoz:

          If you have an upstream ASA.. why would pfsense wan be a /20??  There should be an transit network to your asa.. like a /30 maybe a 29 if you have multiple routers on this transit..

          The ASA with FirePOWER has UTM capabilities pfSense can only dream of so when a client does reach it, it's important that it's the client's real IP address (or something that is derivative of it).  They want all the APs on the same subnet so seamless roaming can happen and there will be a couple if Wifi SIP phones that need to hand off from one AP to another without changing IP address as that would drop the call in progress.  We do it in another building and the phones really do roam from one AP to another and keep the call going but that certainly won't be the case if I break up the broadcast domain.

          It's not often that there will be thousands of people in the building but at times there will be thousands of people in the building and every one of them on the Wifi if they can be.

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          • johnpozJ
            johnpoz LAYER 8 Global Moderator
            last edited by

            "it's important that it's the client's real IP address"

            Yeah ok, which is why you wouldn't nat at pfsense.. And just route the traffic to your asa via a transit.

            In this scenario
            internet - publicIP asa 172.16.0.1 – transit 172.16.0/30 --- 172.16.0.2/30 pfsense 10.0.0.1/20 -- devices on 10.0.0/20

            Your ASA would see the 10.0.0.x address of your client directly..

            Doing a 1to1 nat of rfc1918networkA/20 to network1918networkB/20 is completely pointless..  The only reason you would ever need to do such a thing is for example you had 2 companies that need to talk to each other and they were using the same rfc1918 address space and neither of them were willing to change to a different address space.

            An intelligent man is sometimes forced to be drunk to spend time with his fools
            If you get confused: Listen to the Music Play
            Please don't Chat/PM me for help, unless mod related
            SG-4860 24.11 | Lab VMs 2.8, 24.11

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            • S
              smoores
              last edited by

              @johnpoz:

              Yeah ok, which is why you wouldn't nat at pfsense.. And just route the traffic to your asa via a transit.
              In this scenario
              internet - publicIP asa 172.16.0.1 – transit 172.16.0/30 --- 172.16.0.2/30 pfsense 10.0.0.1/20 -- devices on 10.0.0/20
              Your ASA would see the 10.0.0.x address of your client directly..

              OK!  I'm going to give it a try that way and see if I can make it work. Thanks for the help!  I'll post back here and let you know how it worked out.

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              • DerelictD
                Derelict LAYER 8 Netgate
                last edited by

                @johnpoz

                Multiple segments on a public wifi like that gets problematic because there is no requirement to renew dhcp when you roam from AP to AP so users end up with the wrong IP address for the segment they're now connected to.

                Some of the controllers have the ability to roam the VLAN with the users and some even talk to the switch to enable/disable VLANs on specific ports as necessary. But reducing the broadcast domain from one into several can help even if all the VLANs go to all APs all the time because the object is generally to get the broadcast traffic off the air, not off the gig switchports to the APs. Some tunnel all traffic to the controller via L2TP and roam users around that way. It's a non-trivial problem.

                At a minimum you can get different broadcast domains needing to broadcast at different times and not everything everywhere all at once.

                Chattanooga, Tennessee, USA
                A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                • johnpozJ
                  johnpoz LAYER 8 Global Moderator
                  last edited by

                  Yeah I understand if you have clients roaming from AP to AP the different segments can be an issue.  I mention that in my post ;)

                  So sure use of larger network is a simple solution to the yes completely agree can be non-trivial problem.  The cisco WLC normally tunnel all the traffic back to the controller.

                  Since he has a large area where users most likely do a lot of moving around it would be more of an issue than in say an office building where users are tied more to a specific location and only few AP in the area.  In his scenario guessing they could be roaming to multiple AP as they skate around the ice even..

                  An intelligent man is sometimes forced to be drunk to spend time with his fools
                  If you get confused: Listen to the Music Play
                  Please don't Chat/PM me for help, unless mod related
                  SG-4860 24.11 | Lab VMs 2.8, 24.11

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                  • DerelictD
                    Derelict LAYER 8 Netgate
                    last edited by

                    Caught perusing instead of reading.

                    Chattanooga, Tennessee, USA
                    A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                    DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                    Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                    • JKnottJ
                      JKnott
                      last edited by

                      Yeah it's about 40 X 802.11ac wireless access points for a guest network in a huge building

                      I hope you're not planning on doing this with a bunch of independent APs.  The proper way to do this is with dumb access points and a central controller.  Cisco gear can provide this, though there are others.  That way, no matter what AP you're connected to, you're logged into the controller and can move seamlessly among APs.  With Cisco APs, you'd also need a switch with the controller software loaded.  Also, make sure the access points have a suitable radiation pattern.  Most APs are designed for use without a lot of vertical separation from users.  Arenas tend to have very high ceilings.

                      PfSense running on Qotom mini PC
                      i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                      UniFi AC-Lite access point

                      I haven't lost my mind. It's around here...somewhere...

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                      • S
                        smoores
                        last edited by

                        @johnpoz:

                        And just route the traffic to your asa via a transit.
                        Your ASA would see the 10.0.0.x address of your client directly..

                        Yes, I have to agree that is a better approach and it even worked!  Thanks again!

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                        • S
                          smoores
                          last edited by

                          @JKnott:

                          I hope you're not planning on doing this with a bunch of independent APs.  The proper way to do this is with dumb access points and a central controller.  Cisco gear can provide this, though there are others.  That way, no matter what AP you're connected to, you're logged into the controller and can move seamlessly among APs.  With Cisco APs, you'd also need a switch with the controller software loaded.  Also, make sure the access points have a suitable radiation pattern.  Most APs are designed for use without a lot of vertical separation from users.  Arenas tend to have very high ceilings.

                          No, nothing that silly. It's Ubiquity APs with a controller. I might have been Cisco's biggest fan (our networks otherwise are pure Cisco) but they lost us with the 1852i Mobility Express fiasco where the whole thing kept going down, it was a known problem, it was fixed in version whatever but Cisco TAC couldn't provide the fixed software. That was at least 9 months ago and I just saw another person fall victim to the same issue and the fixed software still isn't available.
                          We ended up returning them all as defective under the 90 day warranty.

                          We did many years ago have autonomous APs from Cisco and our phones roamed seamlessly with no controller. It was only a matter of using the same SSID and having them all on the same layer-2 segment.

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                          • DerelictD
                            Derelict LAYER 8 Netgate
                            last edited by

                            @smoores:

                            @johnpoz:

                            And just route the traffic to your asa via a transit.
                            Your ASA would see the 10.0.0.x address of your client directly..

                            Yes, I have to agree that is a better approach and it even worked!  Thanks again!

                            Thanks for letting us know.

                            Chattanooga, Tennessee, USA
                            A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                            DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                            Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                            • johnpozJ
                              johnpoz LAYER 8 Global Moderator
                              last edited by

                              Glad to hear, but really there was never a question that it was a better approach and would work ;)

                              Natting has always been a workaround/hack to networks that overlap or napt when you need to have many IPs share the use of single ip.  This work around sometimes is useful in rfc1918 space a quick and dirty way to get something done.

                              But in general if there is no absolute reason to nat, then you shouldn't.. If its rfc1918 to rfc1918 and you control both sides then not the way to do it.. And transit networks you would think were some new concept or something. I don't really understand the almost daily posts where they come up, the most common being asymmetrical routing issues because they didn't use a transit.

                              An intelligent man is sometimes forced to be drunk to spend time with his fools
                              If you get confused: Listen to the Music Play
                              Please don't Chat/PM me for help, unless mod related
                              SG-4860 24.11 | Lab VMs 2.8, 24.11

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