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    Nat & ssh problem

    Scheduled Pinned Locked Moved NAT
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    • S
      spazio
      last edited by

      Yes, the lan config is 192.168.0.1/24

      And yes the ssh server has a default route, here is the config:
      root@server:~# route
      Kernel IP routing table
      Destination    Gateway        Genmask        Flags Metric Ref    Use Iface
      192.168.0.0    *              255.255.255.0  U    0      0        0 eth0
      default        pfsense.box    0.0.0.0        UG    100    0        0 eth0

      I also tested it with 2 other ssh server i have on the lan segment and got the same time out from the external.

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      • D
        danswartz
        last edited by

        Hmmm, can you post interface info, nat and rules?

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        • S
          spazio
          last edited by

          The wan
          pppoe with isp and is always connected
          FTP Helper        disable
          Block private networks enable
          Block bogon networks  enable

          The lan
          IP configuration
          Bridge with none
          IP address 192.168.0.1 / 24
          FTP Helper enable

          NAT:
          If          Proto  Ext. port range  NAT IP  Int. port range  Description
          WAN  TCP  22 (SSH)      192.168.0.10                            ssh server
                                                        (ext.: interface ip) 22 (SSH)

          Rules:WAN
          Proto  Source      Port  Destination  Port  Gateway  Schedule  Description
          *  RFC 1918 networks  *      *                  *      *      *  Block private
          *  Reserved            *      *            *        *      *  Block bogon
          TCP            *            *  192.168.0.10  22 (SSH)  *    *    ssh server

          Rules:LAN
          Proto  Source  Port  Destination  Port  Gateway  Schedule  Description
          *      LAN net  *      *          *      *                  Default LAN -> any

          Everything is pretty much iso. There is nothing special about the network.

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          • D
            danswartz
            last edited by

            Odd, looks okay, as far as I can see.  Curious, if you change the port number (on the outside) to some non-standard port (a good idea anyway) like 2222, does it work?

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            • S
              spazio
              last edited by

              This is weird, just tested with port 2500 and here is the raw firewall log entry:

              Mar 17 09:22:52 pf: 586569 rule 71/0(match): block in on ng0: (tos 0x0, ttl 59, id 2421, offset 0, flags [DF], proto TCP (6), length 60) 72.55.39.133.38982 > 74.10.205.142.22: S, cksum 0x5057 (correct), 1651357223:1651357223(0) win 5840 <mss 2="" 3328663370="" 1366,sackok,timestamp="" 0,nop,wscale="">The default deny rule apply and the packet is rejected here it is:
              @71 block drop in log quick all label "Default deny rule"</mss>

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              • D
                danswartz
                last edited by

                did you change the rule too, or just the nat entry?  note that the rule applies to the post-nat, so that would stay port 22.

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                • S
                  spazio
                  last edited by

                  First i deleted the nat and rule on port 22 and then created a new nat on port 2500 that created automaticly the rule.

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                  • D
                    danswartz
                    last edited by

                    it shouldn't have blocked it then :(

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                    • T
                      thafener
                      last edited by

                      Spazio,

                      Did you find a solution for this meanwhile as I have the same problem with NAT over here.
                      I have solved it once in a absolutely strange way. I have delted all FW and NAT rules, made
                      a backup of the box and made a fresh install. Then I have created the rules manually again.
                      Then I have made the rules created by NAT the first ones and it worked for some 10 days
                      but it has stopped working again. :-[

                      cheers thafener

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                      • S
                        spazio
                        last edited by

                        Nop, still have the same problem and it gets worst. I took another machine, did a completly new install from dist cd and the same problem occurs. The default deny rule block everything. I can't even get the packet to go tru once in a while like my other network.

                        Here is my understanding of the problem, the packet are discarded  on a first come first served. It like if the default deny rule is the first, the packet is discarted so the other added rule do not apply.

                        This is weird, nat is usually pretty much strait forward, is there somebody that does technical incident call service?

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                        • D
                          danswartz
                          last edited by

                          can you post your /tmp/rules.debug?

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                          • T
                            thafener
                            last edited by

                            hi danswartz

                            here's mine as a example… renamed it to rules.txt

                            Thx thafener

                            rules.txt

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                            • D
                              danswartz
                              last edited by

                              In a couple of places, you have rules saying {tcp udp} for a tcp service - get rid of the udp it just confuses things.  Also, your post refers to 192.168.0.10, but the rules are referencing 192.168.1.2 - is this an error, or did you change the IPs and not post that?  Anyway, this all looks correct - the only thing I can see as a possible issue (that might explain the inbound SSH request not getting through and not being blocked by PF) is snort.  I have stopped using snort myself, due to false positives that resulted in good hosts being blacklisted.  Could that be it?

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                              • T
                                thafener
                                last edited by

                                Hi danswartz

                                Sorry I did not mean to confuse you, it was not the logfile of the threat starter but I have
                                exactly the same problem, I cannot access 192.168.1.2 in the LAN segment and found no lasting
                                solution so far.
                                Well I am not using snort but I will check the rest

                                Thx thafener

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                                • D
                                  danswartz
                                  last edited by

                                  Oh, sigh.  This is confusing.  I hadn't noticed I was dealing with two different posters :(  So, thafener, when you try to connect to ssh from outside, is it blocked by the default rule or it just goes nowhere?

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                                  • T
                                    thafener
                                    last edited by

                                    Sorry for all that mess danswartz I do not think that the ssh packages are blocked by the default rule as I can see
                                    them pass in the firewall log but I cannot connect to the ssh host which is possible of course from the LAN side.
                                    It is really confusing that I already "solved" this by making the SSH NAT rule the first one and it has been working
                                    fine for a while but unfortunately the problem occured again.
                                    I have a second PFsense system running in a different location and here it is the same with natting FTP.
                                    I cannot access both boxes from here but I'' get back to this with a little more detailed log output tomorrow morning.

                                    cheers thafener

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                                    • T
                                      thafener
                                      last edited by

                                      Ok here's some output and some screenshots of this phenomenon…first of
                                      all a packet capture of the WAN interface on Port 22...

                                      08:09:08.760774 IP 217.71.243.136.1651 > 83.79.5.14.22: tcp 0
                                      08:09:11.726431 IP 217.71.243.136.1651 > 83.79.5.14.22: tcp 0
                                      08:09:17.742044 IP 217.71.243.136.1651 > 83.79.5.14.22: tcp 0
                                      

                                      Please find the screenshots of the NAT rule and the Log viewer attached
                                      below…

                                      fwlog1.jpg
                                      fwlog1.jpg_thumb
                                      fwrule1.jpg
                                      fwrule1.jpg_thumb

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                                      • D
                                        danswartz
                                        last edited by

                                        Are you absolutely 100% positive there is no trace of the connection on LAN side?  Can you run a capture there too?

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                                        • T
                                          thafener
                                          last edited by

                                          I have made a captore in full detail but could not find packets on port 22 for host 192.168.1.2  :-\

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                                          • D
                                            danswartz
                                            last edited by

                                            Can you capture anything at all on the LAN side involving 192.168.1.2 or port 22 (e.g. two captures.)

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