Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    Getting a default denied rule after setting up the firewall rules

    Firewalling
    2
    28
    7.6k
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • T
      TimDows
      last edited by

      Hi all,

      Situation
      LAN –-  pfSense  --- OPT1
                              --- OPT2
                              --- OPT3

      I want to be able to open a telnet session to the computer on the LAN network (with static IP) from the internet through the OPT3 interface.
      But I'm getting a default denied error after I made some firewall and NAT settings:


      Its getting in as we can see, but the connection is not allowed to talk back????

      My OPT3 firewall rules (That works as we can see above):

      My LAN firewall rules (That strangely doesn't work):

      • I tried to set the gateway on the LAN firewall rule to default, but didn't work.
      • I tried to change the source in the LAN firewall rule to LAN Subnet, but no luck.
        Has any body got an idea what I'm missing to get this to work?

      Best regards,
      Tim

      1 Reply Last reply Reply Quote 0
      • E
        Eugene
        last edited by

        Please give us your NAT page.

        http://ru.doc.pfsense.org

        1 Reply Last reply Reply Quote 0
        • T
          TimDows
          last edited by

          @Eugene:

          Please give us your NAT page.

          Added my NAT settings to the post above.

          1 Reply Last reply Reply Quote 0
          • E
            Eugene
            last edited by

            Do you use loadbalancers?

            http://ru.doc.pfsense.org

            1 Reply Last reply Reply Quote 0
            • T
              TimDows
              last edited by

              @Eugene:

              Do you use loadbalancers?

              Yes indeed! The 3 OPTs are combined in a loadbalancing service.

              1 Reply Last reply Reply Quote 0
              • E
                Eugene
                last edited by

                try to create a rule on the top of your rules on LAN interface:
                allow any from 10.0.0.10 to 99.199.45.221 any gateway=OPT3

                http://ru.doc.pfsense.org

                1 Reply Last reply Reply Quote 0
                • T
                  TimDows
                  last edited by

                  @Eugene:

                  try to create a rule on the top of your rules on LAN interface:
                  allow any from 10.0.0.10 to 99.199.45.221 any gateway=OPT3

                  I think I already did, see the LAN firewall settings in my first post (last image)

                  1 Reply Last reply Reply Quote 0
                  • E
                    Eugene
                    last edited by

                    Have you done packet trace on all 'public' interfaces? kind of
                    tcpdump -ni <opt1>host 99.199.45.221
                    I suspect that your traffic is routed back through srong interface… I might be wrong.</opt1>

                    http://ru.doc.pfsense.org

                    1 Reply Last reply Reply Quote 0
                    • T
                      TimDows
                      last edited by

                      @Eugene:

                      Have you done packet trace on all 'public' interfaces? kind of
                      tcpdump -ni <opt1>host 99.199.45.221
                      I suspect that your traffic is routed back through srong interface… I might be wrong.</opt1>

                      I'm gonna give it a try in 10 minutes, but the firewall logs show that the LAN interface is blocking, therefore I think this is not the problem.

                      1 Reply Last reply Reply Quote 0
                      • E
                        Eugene
                        last edited by

                        and please try to catch states during your session
                        pfctl -ss | grep 99.199.45.221

                        http://ru.doc.pfsense.org

                        1 Reply Last reply Reply Quote 0
                        • T
                          TimDows
                          last edited by

                          Got some detailed information here:

                          The tcpdump shows that its comming in over OPT3(re3) and is leaving over LAN(em0)

                          # tcpdump -ni re3 host 91.199.45.221
                          tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
                          listening on re3, link-type EN10MB (Ethernet), capture size 96 bytes
                          18:58:44.729579 IP 10.0.30.254.62553 > 91.199.45.221.2121: P 777542828:777542880(52) ack 2007138495 win 256
                          18:58:44.767884 IP 91.199.45.221.2121 > 10.0.30.254.62553: P 1:69(68) ack 52 win 142
                          18:58:44.938819 IP 10.0.30.254.62553 > 91.199.45.221.2121: P 52:104(52) ack 69 win 255
                          18:58:44.976814 IP 91.199.45.221.2121 > 10.0.30.254.62553: P 69:121(52) ack 104 win 142
                          18:58:44.992309 IP 91.199.45.221.2121 > 10.0.30.254.62553: P 121:189(68) ack 104 win 142
                          18:58:44.993159 IP 10.0.30.254.62553 > 91.199.45.221.2121: . ack 189 win 255
                          18:58:44.993204 IP 91.199.45.221.60954 > 10.0.30.254.23: S 3624875656:3624875656(0) win 5840 <mss 6="" 1899518575="" 1460,sackok,timestamp="" 0,nop,wscale="">18:58:47.992676 IP 91.199.45.221.60954 > 10.0.30.254.23: S 3624875656:3624875656(0) win 5840 <mss 6="" 1899519325="" 1460,sackok,timestamp="" 0,nop,wscale="">18:58:53.992731 IP 91.199.45.221.60954 > 10.0.30.254.23: S 3624875656:3624875656(0) win 5840 <mss 6="" 1899520825="" 1460,sackok,timestamp="" 0,nop,wscale="">18:59:05.992463 IP 91.199.45.221.60954 > 10.0.30.254.23: S 3624875656:3624875656(0) win 5840</mss></mss></mss> 
                          
                          # tcpdump -ni em0 host 91.199.45.221
                          tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
                          listening on em0, link-type EN10MB (Ethernet), capture size 96 bytes
                          18:59:24.676558 IP 10.0.0.10.49403 > 91.199.45.221.2121: P 777542932:777542984(52) ack 2007138683 win 255
                          18:59:24.716246 IP 91.199.45.221.2121 > 10.0.0.10.49403: P 1:85(84) ack 52 win 142
                          18:59:24.716261 IP 91.199.45.221.2121 > 10.0.0.10.49403: P 85:153(68) ack 52 win 142
                          18:59:24.717408 IP 10.0.0.10.49403 > 91.199.45.221.2121: . ack 153 win 254
                          18:59:25.369123 IP 10.0.0.10.49403 > 91.199.45.221.2121: P 52:104(52) ack 153 win 254
                          18:59:25.407223 IP 91.199.45.221.2121 > 10.0.0.10.49403: P 153:221(68) ack 104 win 142
                          18:59:25.607598 IP 10.0.0.10.49403 > 91.199.45.221.2121: P 104:156(52) ack 221 win 254
                          18:59:25.645676 IP 91.199.45.221.2121 > 10.0.0.10.49403: P 221:273(52) ack 156 win 142
                          18:59:25.661707 IP 91.199.45.221.2121 > 10.0.0.10.49403: P 273:341(68) ack 156 win 142
                          18:59:25.661775 IP 91.199.45.221.43367 > 10.0.0.10.23: S 3684512266:3684512266(0) win 5840 <mss 6="" 1899528742="" 1460,sackok,timestamp="" 0,nop,wscale="">18:59:25.662563 IP 10.0.0.10.49403 > 91.199.45.221.2121: . ack 341 win 253
                          18:59:25.665811 IP 10.0.0.10.8 > 91.199.45.221.43367: S 4157337059:4157337059(0) ack 3684512267 win 4128 <mss 536="">18:59:27.667055 IP 10.0.0.10.1 > 91.199.45.221.43367: S 4157337059:4157337059(0) ack 3684512267 win 4128 <mss 536="">18:59:28.660593 IP 91.199.45.221.43367 > 10.0.0.10.23: S 3684512266:3684512266(0) win 5840 <mss 6="" 1899529492="" 1460,sackok,timestamp="" 0,nop,wscale="">18:59:28.662051 IP 10.0.0.10.8 > 91.199.45.221.43367: . ack 1 win 4128
                          18:59:31.667660 IP 10.0.0.10.1 > 91.199.45.221.43367: S 4157337059:4157337059(0) ack 3684512267 win 4128</mss></mss></mss></mss> 
                          

                          And the pf gives me:

                          # pfctl -ss | grep 91.199.45.221
                          all tcp 91.199.45.221:2121 <- 10.0.0.10:49403       ESTABLISHED:ESTABLISHED
                          all tcp 10.0.0.10:49403 -> 10.0.30.254:62553 -> 91.199.45.221:2121       ESTABLISHED:ESTABLISHED
                          all tcp 10.0.0.10:23 <- 10.0.30.254:23 <- 91.199.45.221:60951       CLOSED:SYN_SENT
                          all tcp 91.199.45.221:60951 -> 10.0.0.10:23       SYN_SENT:CLOSED
                          all tcp 10.0.0.10:23 <- 10.0.30.254:23 <- 91.199.45.221:60954       CLOSED:SYN_SENT
                          all tcp 91.199.45.221:60954 -> 10.0.0.10:23       SYN_SENT:CLOSED
                          all tcp 10.0.0.10:23 <- 10.0.30.254:23 <- 91.199.45.221:43367       CLOSED:SYN_SENT
                          all tcp 91.199.45.221:43367 -> 10.0.0.10:23       SYN_SENT:CLOSED
                          
                          
                          1 Reply Last reply Reply Quote 0
                          • E
                            Eugene
                            last edited by

                            # tcpdump -ni em0 host 91.199.45.221
                            tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
                            listening on em0, link-type EN10MB (Ethernet), capture size 96 bytes
                            ...
                            18:59:25.661775 IP 91.199.45.221.43367 > 10.0.0.10.23: S 3684512266:3684512266(0) win 5840 <mss 6="" 1899528742="" 1460,sackok,timestamp="" 0,nop,wscale="">18:59:25.662563 IP 10.0.0.10.49403 > 91.199.45.221.2121: . ack 341 win 253
                            18:59:25.665811 IP 10.0.0.10.8 > 91.199.45.221.43367: S 4157337059:4157337059(0) ack 3684512267 win 4128 <mss 536="">18:59:27.667055 IP 10.0.0.10.1 > 91.199.45.221.43367: S 4157337059:4157337059(0) ack 3684512267 win 4128 <mss 536="">18:59:28.660593 IP 91.199.45.221.43367 > 10.0.0.10.23: S 3684512266:3684512266(0) win 5840 <mss 6="" 1899529492="" 1460,sackok,timestamp="" 0,nop,wscale="">18:59:28.662051 IP 10.0.0.10.8 > 91.199.45.221.43367: . ack 1 win 4128
                            18:59:31.667660 IP 10.0.0.10.1 > 91.199.45.221.43367: S 4157337059:4157337059(0) ack 3684512267 win 4128</mss></mss></mss></mss> 
                            

                            I can't see your 10.0.0.10 responding with syn,ack. Can you? So, it does not accept tcp-connection at port 23.

                            http://ru.doc.pfsense.org

                            1 Reply Last reply Reply Quote 0
                            • T
                              TimDows
                              last edited by

                              Hmmm…

                              Fact is that the 10.0.0.10 device is trying to reply to the telnet session because:

                              • I can connect from inside the lan locally to this device;
                              • The LAN firewall rules are picking up a reply generated by the telnet session trying to connect (See 2nd image in first post)
                              1 Reply Last reply Reply Quote 0
                              • E
                                Eugene
                                last edited by

                                pfSense does not see syn,ack, it means your 10.0.0.10 does not route 91.199.45.221 back to pfSense.

                                http://ru.doc.pfsense.org

                                1 Reply Last reply Reply Quote 0
                                • T
                                  TimDows
                                  last edited by

                                  @Eugene:

                                  pfSense does not see syn,ack, it means your 10.0.0.10 does not route 91.199.45.221 back to pfSense.

                                  Thanks for the help so far by the way!
                                  But 'unfortunately' the 10.0.0.10 can connect to this ip using http

                                  1 Reply Last reply Reply Quote 0
                                  • E
                                    Eugene
                                    last edited by

                                    I think it would be more clear if you could tcpdump on 10.0.0.10 to see whether it responds to  IP 91.199.45.221.43367 > 10.0.0.10.23: S
                                    Can you?

                                    http://ru.doc.pfsense.org

                                    1 Reply Last reply Reply Quote 0
                                    • T
                                      TimDows
                                      last edited by

                                      Sure I can check this:

                                      # tcpdump -ni em0 | grep 91.199.45.221
                                      tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
                                      listening on em0, link-type EN10MB (Ethernet), capture size 96 bytes
                                      22:12:57.604130 IP 91.199.45.221.34002 > 10.0.0.10.23: S 3047972562:3047972562(0) win 5840 <mss 6="" 1902431548="" 1460,sackok,timestamp="" 0,nop,wscale="">22:12:57.607788 IP 10.0.0.10.18 > 91.199.45.221.34002: S 564746040:564746040(0) ack 3047972563 win 4128 <mss 536="">22:12:59.608156 IP 10.0.0.10.1 > 91.199.45.221.34002: S 564746040:564746040(0) ack 3047972563 win 4128 <mss 536="">22:13:00.606330 IP 91.199.45.221.34002 > 10.0.0.10.23: S 3047972562:3047972562(0) win 5840 <mss 6="" 1902432298="" 1460,sackok,timestamp="" 0,nop,wscale="">22:13:00.607776 IP 10.0.0.10.18 > 91.199.45.221.34002: . ack 1 win 4128
                                      22:13:03.608388 IP 10.0.0.10.1 > 91.199.45.221.34002: S 564746040:564746040(0) ack 3047972563 win 4128 <mss 536="">22:13:06.606098 IP 91.199.45.221.34002 > 10.0.0.10.23: S 3047972562:3047972562(0) win 5840 <mss 6="" 1902433798="" 1460,sackok,timestamp="" 0,nop,wscale="">22:13:06.607501 IP 10.0.0.10.18 > 91.199.45.221.34002: . ack 1 win 4128
                                      22:13:11.608230 IP 10.0.0.10.1 > 91.199.45.221.34002: S 564746040:564746040(0) ack 3047972563 win 4128 <mss 536="">22:13:18.605858 IP 91.199.45.221.34002 > 10.0.0.10.23: S 3047972562:3047972562(0) win 5840 <mss 6="" 1902436798="" 1460,sackok,timestamp="" 0,nop,wscale="">22:13:18.607577 IP 10.0.0.10.18 > 91.199.45.221.34002: . ack 1 win 4128</mss></mss></mss></mss></mss></mss></mss></mss> 
                                      

                                      And the firewall messages:

                                      Might it have something to do that I'm using the loadbalacing service?

                                      1 Reply Last reply Reply Quote 0
                                      • E
                                        Eugene
                                        last edited by

                                        If you think this```
                                        22:12:57.604130 IP 91.199.45.221.34002 > 10.0.0.10.23: S 3047972562:3047972562(0) win 5840 <mss 6="" 1902431548="" 1460,sackok,timestamp="" 0,nop,wscale="">22:12:57.607788 IP 10.0.0.10.18 > 91.199.45.221.34002: S 564746040:564746040(0) ack 3047972563 win 4128</mss>

                                        is correct then you are probably wrong.
                                        Why you have in source 10.0.0.10.18 instead of 10.0.0.10.23 ??? I am confused…

                                        http://ru.doc.pfsense.org

                                        1 Reply Last reply Reply Quote 0
                                        • T
                                          TimDows
                                          last edited by

                                          I haven't got the slithest idea what it could be.
                                          I'm thinking of a reinstall with only 1WAN and then try to NAT something.

                                          I'll let you know tomorrow (11 PM over here already)

                                          1 Reply Last reply Reply Quote 0
                                          • E
                                            Eugene
                                            last edited by

                                            I would blame 10.0.0.10 here.
                                            Make local connection with network dumps.
                                            … or good night -)

                                            http://ru.doc.pfsense.org

                                            1 Reply Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.