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    Assistance with an internal port forward

    Scheduled Pinned Locked Moved NAT
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    • T
      Trel
      last edited by

      I'm trying to get an internal port forward to work.

      I have a domain pointed (internally) to my firewall.

      What I'm trying to make is a NAT rule that directs a port to another internal IP

      So if I try to hit my firewall at port 10060, it directs it to the specific server at 10060

      The rule I made was

      Interface: LAN
      Source: Any
      Destination: 10.9.0.1 <– Firewall
      Destination Port: 10060
      Target: 10.9.0.10 <--- Internal server 
      Target Port: 10060

      This doesn't work

      However, if I change Destination from 10.9.0.1 to ANY, it works, so I'm not sure why that is, but I don't want to globally override that port.

      Can anyone help?

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      • M
        muswellhillbilly
        last edited by

        Why would you want to do this? Why not just set your internal DNS to point directly to the internal server instead of your firewall? You're just trying to bounce a forward from an internal host to another internal host via the firewall's internal interface. Unless I misread your post.

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        • DerelictD
          Derelict LAYER 8 Netgate
          last edited by

          Yeah. Bouncing connections in and back out of the same interface is doomed to failure. Sometimes in strange, unpredictable, and intermittent ways. Just don't do it.

          If you really need this put the asset you are redirecting to on another interface and redirect to that.  That will work fine.

          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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          • T
            Trel
            last edited by

            @muswellhillbilly:

            Why would you want to do this? Why not just set your internal DNS to point directly to the internal server instead of your firewall? You're just trying to bounce a forward from an internal host to another internal host via the firewall's internal interface. Unless I misread your post.

            Externally my domain points to my firewall and has specific ports forwarded to specific machines for different services.
            Internally my domain ALSO points to my firewall.

            I'm trying to achieve the same thing.

            For example, one machine hosts and IceCast2 server for music streaming.

            Right now people can go to http://mydomain.com:10060/stream.m3u and listen.
            However, if they're on my network, that doesn't work.

            If I point my DNS to the one server internally, I remove the ability to reach ALL other servers with the same name.

            If you really need this put the asset you are redirecting to on another interface and redirect to that.  That will work fine.

            Unfortunately, that's not possible as I need that resource to be on LAN due to it's other purposes.

            I should mention again, that if I do the port forward with destination set to ANY it works, but if I only put in the firewall's IP, use the "This Firewall" alias, or 127.0.0.1 it doesn't work.
            That suggests to me there is a correct thing to use for the destination to make this work, if using "Any" does work.

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            • johnpozJ
              johnpoz LAYER 8 Global Moderator
              last edited by

              "If I point my DNS to the one server internally, I remove the ability to reach ALL other servers with the same name."

              Huh???  You just create a record for mydomain.com that points to your internal IP on your internal dns..

              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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              • T
                Trel
                last edited by

                @johnpoz:

                "If I point my DNS to the one server internally, I remove the ability to reach ALL other servers with the same name."

                Huh???  You just create a record for mydomain.com that points to your internal IP on your internal dns..

                Maybe I worded that poorly

                Externally
                domain.com:80 -> Server A
                domain.com:81 -> Server B
                domain.com:82 -> Server C

                If I point the DNS for domain.com to any one of those servers, I relinquish the ability to have the other two accessible.
                What I'm trying to do is point the DNS internally to the firewall and then use NAT to forward the ports back to the correct servers.

                EDIT: added pictures of the rule that works and the rule that doesn't.
                (But the rule that works is too broad, I want to be specific as I don't want to forward ALL attempts at 10068, just the ones that target the firewall itself).

                intnat_works.png
                intnat_works.png_thumb
                intnat_doesntwork.png
                intnat_doesntwork.png_thumb

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                • johnpozJ
                  johnpoz LAYER 8 Global Moderator
                  last edited by

                  why not just do

                  server1.domain.tld publicIP –- serverA privateIP-A
                  server2.domain.tld publicIP --- serverB privateIP-B
                  server3.domain.tld publicIP --- serverC privateIP-C

                  then on internal
                  server1.domain.tld privateIP-A
                  server2.domain.tld privateIP-B
                  server3.domain.tld privateIP-C

                  Much cleaner solution..

                  If you don't want to use the :port in your url just setup reverse proxy on pfsense.

                  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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                  • T
                    Trel
                    last edited by

                    @johnpoz:

                    why not just do

                    server1.domain.tld publicIP –- serverA privateIP-A
                    server2.domain.tld publicIP --- serverB privateIP-B
                    server3.domain.tld publicIP --- serverC privateIP-C

                    then on internal
                    server1.domain.tld privateIP-A
                    server2.domain.tld privateIP-B
                    server3.domain.tld privateIP-C

                    Much cleaner solution..

                    If you don't want to use the :port in your url just setup reverse proxy on pfsense.

                    If I was doing it from scratch, I would have done it that way, but I'm not.  There's hard coded things going years back that used to all run off a single server.

                    I know it's not best practice, but it's what I need to do for my scenario.

                    Based on the pictures I uploaded, you can see there HAS to be some way to make it work given my constraints.  I just need to find out what it is.
                    Considering it works with the destination being "Any", then there must be some destination(s) that will make it work.

                    (And for what it's worth, I'm pushing to have some of that changed so I CAN use best practices)

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                    • M
                      muswellhillbilly
                      last edited by

                      @Trel:

                      If I was doing it from scratch, I would have done it that way, but I'm not.  There's hard coded things going years back that used to all run off a single server.

                      I know it's not best practice, but it's what I need to do for my scenario.

                      I'm not sure what you mean by 'hard coded things', but if you just need to resolve one host internally then surely a DNS override would work just as well. You just need to enter the address for one host - how hard can it be?

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                      • T
                        Trel
                        last edited by

                        @muswellhillbilly:

                        @Trel:

                        If I was doing it from scratch, I would have done it that way, but I'm not.  There's hard coded things going years back that used to all run off a single server.

                        I know it's not best practice, but it's what I need to do for my scenario.

                        I'm not sure what you mean by 'hard coded things', but if you just need to resolve one host internally then surely a DNS override would work just as well. You just need to enter the address for one host - how hard can it be?

                        Ok, I have two things off the top of my head that are hard coded.

                        One is hardcoded to look at: http://domain.com:8080/path_to_xml/file.xml
                        One is hardcoded to look at: http://domain.com:10060/stream128.m3u

                        The webserver which serves the XML is one one server, the IceCast server which serves the m3u is on a second server.

                        How would I achieve this with a DNS override?

                        Pfsense: I can change
                        Servers Themselves: I can change
                        DNS: I can change
                        Devices that look at those URLs and Ports: I cannot change

                        What are you suggesting I do here?

                        (I'm sorry if I sound a bit snappy here, I'm just not sure how I'm supposed to point DNS to two different locations for the same name without NAT as well.  And I'm dealing with an excellent bug in my registrar's UI that has locked me out of making any DNS changes at all on two of my domains.  Didn't meant to take out my bad day on you)

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                        • DerelictD
                          Derelict LAYER 8 Netgate
                          last edited by

                          I try to tell people that domain.com shouldn't be used as a hostname. I always lose. Whoever did that painted you into a corner.

                          So you're saying both those URLs need to go to different destination servers?

                          Yes, you'll need a port forward.  Doing it with the clients on the same subnet as the servers is going to be pretty hokey. You see, NAT is a router function and you don't route same-subnet traffic so anything that "works" will be a hack.

                          My recommendation is to put the servers (which you say you can change) on a different subnet and NAT port forwards will work fine. But you've already said you can't do that either.

                          You might try enabling the NAT destination IP again and and checking Static route filtering in System > Advanced > Firewall/NAT tab .

                          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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                          • T
                            Trel
                            last edited by

                            @Derelict:

                            I try to tell people that domain.com shouldn't be used as a hostname. I always lose. Whoever did that painted you into a corner.

                            So you're saying both those URLs need to go to different destination servers?

                            Yes, you'll need a port forward.  Doing it with the clients on the same subnet as the servers is going to be pretty hokey. You see, NAT is a router function and you don't route same-subnet traffic so anything that "works" will be a hack.

                            My recommendation is to put the servers (which you say you can change) on a different subnet and NAT port forwards will work fine. But you've already said you can't do that either.

                            You might try enabling the NAT destination IP again and and checking Static route filtering in System > Advanced > Firewall/NAT tab .

                            Well it's not domain.com specifically, I don't think they want me mentioning their real one.  But I agree.  My home setup has an internal domain, but I use s1.trel.co, s2.trel.co, etc to separate them even when they all point to the same IP externally.

                            For the static route filtering option, it refers to defined interfaces, not physical ones, right?

                            Do you have any idea at all why the NAT rule I have in the picture I uploaded earlier works when it's destination is * vs any one IP/Alias?

                            EDIT: the static route filtering option didn't make a difference, if it absolutely can't be done without forwarding ALL destinations at that port, I'll have to tell them it can't be done.

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                            • DerelictD
                              Derelict LAYER 8 Netgate
                              last edited by

                              If I have time I'll lab it tonight.  I don't know if you need to enable NAT reflection or another hack to make it work.

                              Just so I'm clear you want:

                              pfSense: 192.168.1.1/24
                              ifAlias VIP: 192.168.1.2
                              Host 1: 192.168.1.100
                              Server 1: 192.168.1.200

                              Port forward connections from 192.168.1.100 to 192.168.1.2:8000 to 192.168.1.200:8000 instead.

                              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

                                You want a simpler solution.. Run those services on the same box - since the moron that hard coded a single name thought that was how it worked..  Also agree using a domain name as FQDN to point to a host is a bad ide.. host.domain.tld should always be used..

                                Fix the hard code.. Which again is BAD idea…

                                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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                                • M
                                  muswellhillbilly
                                  last edited by

                                  I'm in agreement with JP on this one. The more you try to work around the bad decisions made before you inherited this system, the more convoluted and unmanageable your environment will become. You have an opportunity to fix things here rather than just work around them. Otherwise you'll only make your life and the life of guy who eventually inherits your network more miserable in the long run.

                                  Puts me in mind of the following classic image: http://blog.thingsdesigner.com/uploads/id/tree_swing_development_requirements.jpg

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                                  • johnpozJ
                                    johnpoz LAYER 8 Global Moderator
                                    last edited by

                                    ^ exactly… You also have some moron hard coding ports in the url??  This is also really bad practice if you ask me...

                                    Also lets clarify "hardcode"  your saying the application has http://domain.com:8080/path_to_xml/file.xml in its code, and to change that has to be recompiled?  Or are you saying its in the registry and or conf or ini file that controls the application.. And you just don't want to push out the update to the configuration?

                                    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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                                    • T
                                      Trel
                                      last edited by

                                      @johnpoz:

                                      ^ exactly… You also have some moron hard coding ports in the url??  This is also really bad practice if you ask me...

                                      Also lets clarify "hardcode"  your saying the application has http://domain.com:8080/path_to_xml/file.xml in its code, and to change that has to be recompiled?  Or are you saying its in the registry and or conf or ini file that controls the application.. And you just don't want to push out the update to the configuration?

                                      It's not that they don't want to push out the configuration, but that the devices it's on need to have the configuration changed, which can't be done remotely.  (Not that they don't want to push out config, but that there's no mechanism to do so here). An example using the Icecast server.  It's a playlist included with the device that has the proper URI to the Icecast server.  I could change it in the config on their devices, but I can't do that without the device.  Remotely changing it isn't an option.  On the one I have sitting next to me, I already did, but the guy three states over, not so much.

                                      However, they won't be available to change any time in the near future.  If I change it to multiple subdomains off the hostname, I break it for everyone who's currently remote.  If I don't, I'm apparently breaking (or rather, not making it work) for everyone who is local at the moment.

                                      Only possible workable solution if port forwarding is not an option is to use DNS to make multiple names, and deal with the remote ones as they come in.
                                      It looks like it's going to be a case of "It's definitely not the best way, it's just the only way".

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                                      • T
                                        Trel
                                        last edited by

                                        For anyone wondering what I ended up doing was setting up DNS entries for the different servers.

                                        Externally, they all point to the same IP, internally, to the different servers.
                                        As I get my hands on the devices with the old config, I'll update them accordingly.

                                        Since it's all going off a single IP, the external devices which I can't updated would work just as well with domain.com as with server01.domain.com when it comes to the port forward externally.

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