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    [SOLVED] Do not log TCP packets with flags TCP:RA / TCP:PA etc.

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    • M
      mcury @johnpoz
      last edited by

      @johnpoz said in Do not log TCP packets with flags TCP:RA / TCP:PA etc.:

      You might want to limit that to interesting ports if your goal is trim down the amount of noise your logging. My interesting ports is a pretty long list, but it does reduce some of the noise not logging every port ;)

      I'll start preparing that list now.. =)

      johnpozJ 1 Reply Last reply Reply Quote 0
      • johnpozJ
        johnpoz LAYER 8 Global Moderator @mcury
        last edited by johnpoz

        @mcury here is my list.. It prob way longer than need/should be but I had does some looking to what ports to put in there while back..

        2:3 Entry added Thu, 17 Oct 2019 06:17:40 -0500
7 Entry added Thu, 17 Oct 2019 06:17:40 -0500
9 Entry added Thu, 17 Oct 2019 06:17:40 -0500
13 Entry added Thu, 17 Oct 2019 06:17:40 -0500
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67:69 Entry added Thu, 17 Oct 2019 06:17:40 -0500
80 Entry added Thu, 17 Oct 2019 06:17:40 -0500
88 Entry added Thu, 17 Oct 2019 06:17:40 -0500
111:113 Entry added Thu, 17 Oct 2019 06:17:40 -0500
120 Entry added Thu, 17 Oct 2019 06:17:40 -0500
135:139 Entry added Thu, 17 Oct 2019 06:17:40 -0500
158 Entry added Thu, 17 Oct 2019 06:17:40 -0500
161:162 Entry added Thu, 17 Oct 2019 06:17:40 -0500
177 Entry added Thu, 17 Oct 2019 06:17:40 -0500
192 Entry added Thu, 17 Oct 2019 06:17:40 -0500
199 Entry added Thu, 17 Oct 2019 06:17:40 -0500
207 Entry added Thu, 17 Oct 2019 06:17:40 -0500
217 Entry added Thu, 17 Oct 2019 06:17:40 -0500
363 Entry added Thu, 17 Oct 2019 06:17:40 -0500
389 Entry added Thu, 17 Oct 2019 06:17:40 -0500
402 Entry added Thu, 17 Oct 2019 06:17:40 -0500
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682:689 Entry added Thu, 17 Oct 2019 06:17:40 -0500
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767 Entry added Thu, 17 Oct 2019 06:17:40 -0500
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1007:1008 Entry added Thu, 17 Oct 2019 06:17:40 -0500
1012:1014 Entry added Thu, 17 Oct 2019 06:17:40 -0500
1019:1051 Entry added Thu, 17 Oct 2019 06:17:40 -0500
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53 Entry added Thu, 17 Oct 2019 12:07:49 -0500
123 Entry added Sat, 11 Apr 2020 02:33:04 -0500
33434 Odd port from pfsense forums

        Wow from 2019, man time flies.. Doesn't seem like that long ago that I did that ;)

        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 24.03 | Lab VMs 2.7.2, 24.03

        M 1 Reply Last reply Reply Quote 1
        • m0ursM
          m0urs @bmeeks
          last edited by m0urs

          @bmeeks
          Unfortunately it seems not to work that way. I still get packets logged with these flags set:

          c34ff848-a91c-4dac-b2c0-93681a5621eb-image.png

          Do not get confused, I named my self created rule "Default blocking rule", but the ID is my own rule and not the pfSense default rule.

          Here is the rule I created:

          7bf8dc21-035c-46ff-9776-31373ad24ce9-image.png

          93835a43-fd4b-44a4-9cb9-36b3b01363be-image.png

          What am I doing wrong?

          M 1 Reply Last reply Reply Quote 0
          • M
            mcury @johnpoz
            last edited by mcury

            @johnpoz Wol, that is indeed a long list, I was thinking about ports:

            7 WOL common used
9 WOL default
53 DNS
67:68 DHCP
80 QUIC
88 Kerberos
123 NTP
443 QUIC
500 IPsec
514 Syslog
1194:1198 Common OpenVPN ports..
4500 NAT-T
            johnpozJ 1 Reply Last reply Reply Quote 0
            • M
              mcury @m0urs
              last edited by

              @m0urs said in Do not log TCP packets with flags TCP:RA / TCP:PA etc.:

              What am I doing wrong?

              Did you disable this ?

              24112498-ef2f-4826-9425-2ac6a8912499-image.png

              m0ursM 1 Reply Last reply Reply Quote 0
              • johnpozJ
                johnpoz LAYER 8 Global Moderator @mcury
                last edited by johnpoz

                @mcury yeah its a bit long.. I went a bit overboard when was looking into ports that might be good to log.. I could prob trim it down.. But I really don't see much udp traffic even with that long list.

                Yeah default deny logging is off

                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 24.03 | Lab VMs 2.7.2, 24.03

                1 Reply Last reply Reply Quote 0
                • m0ursM
                  m0urs @mcury
                  last edited by

                  @mcury said in Do not log TCP packets with flags TCP:RA / TCP:PA etc.:

                  Did you disable this ?

                  Yes.

                  As I said: The logging comes from my own created rule and not from the pfSense default blocking rule.

                  M 1 Reply Last reply Reply Quote 0
                  • M
                    mcury @m0urs
                    last edited by

                    @m0urs said in Do not log TCP packets with flags TCP:RA / TCP:PA etc.:

                    The logging comes from my own created rule and not from the pfSense default blocking rule.

                    I'm trying to replicate this here, but now filtering TCP:S only, in my LAN networks.

                    M 1 Reply Last reply Reply Quote 0
                    • M
                      mcury @mcury
                      last edited by

                      Are you using that "Invert match" option for source or destination in that rule ? So far, I'm unable to replicate this behavior here but I'm not using those options.

                      m0ursM 2 Replies Last reply Reply Quote 0
                      • m0ursM
                        m0urs @mcury
                        last edited by

                        @mcury No, I do not use "Invert Match". That is my definition, together with that TCP Flags option mentioned above:

                        5e3f4c21-62e3-46e7-a1c4-963fee7d2124-image.png

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                        • m0ursM
                          m0urs @mcury
                          last edited by

                          @mcury ah, maybe this does not work if protocol set to "Any"? I will try with Protocol set to "TCP" ...

                          m0ursM 1 Reply Last reply Reply Quote 0
                          • m0ursM
                            m0urs @m0urs
                            last edited by

                            @mcury

                            No, unfortunately that did not change anything. These kind of packets are still logged by that rule:

                            70421b24-d1ae-41af-bf94-6343b09cd5ad-image.png

                            You you explain me a bit more, what how this "TCP flag" setting is working? I still did not get it. What exactly is meant by "set" and "out of"?

                            M 1 Reply Last reply Reply Quote 0
                            • M
                              mcury @m0urs
                              last edited by

                              @m0urs said in Do not log TCP packets with flags TCP:RA / TCP:PA etc.:

                              What exactly is meant by "set" and "out of"?

                              https://docs.netgate.com/pfsense/en/latest/firewall/configure.html#tcp-flags

                              m0ursM 1 Reply Last reply Reply Quote 0
                              • m0ursM
                                m0urs @mcury
                                last edited by m0urs

                                @mcury

                                "By default, new pass rules for TCP only check for the TCP SYN flag to be set, out of a possible set of SYN and ACK."

                                Hm, so I would say that I just need to create a normal rule without any options enabled in "TCP flag"? In this case I do get a logging entry if there is something blocked with SYNC flag and no more logging entries for all the other packtes?

                                That would be what I wanted?

                                Update: It says "new PASS rules", but I have a REJECT rule?

                                M 1 Reply Last reply Reply Quote 0
                                • M
                                  mcury @m0urs
                                  last edited by

                                  @m0urs said in Do not log TCP packets with flags TCP:RA / TCP:PA etc.:

                                  @mcury

                                  "By default, new pass rules for TCP only check for the TCP SYN flag to be set, out of a possible set of SYN and ACK."

                                  Hm, so I would say that I just need to create a normal rule without any options enabled in "TCP flag"? In this case I do get a logging entry if there is something blocked with SYNC flag and no more logging entries for all the other packtes?

                                  That would be what I wanted?

                                  Yes, try that and report back.
                                  Other option would be to create a new rule below that one, and set flags to all but SYN, and set to no log.

                                  m0ursM 1 Reply Last reply Reply Quote 0
                                  • m0ursM
                                    m0urs @mcury
                                    last edited by

                                    @mcury I had a look into the Packet Filter rules generated by pfSense.

                                    Could it be that these options are only used for PASS rules but not for BLOCK rules?

                                    Here is the output for that rule either with PASS:

                                    [2.7.2-RELEASE][root@router02.urs.lan]/root: pfctl -vvsr | grep "33276"

@177 pass in log quick on igb2.20 inet all flags S/SA keep state label "USER_RULE" label "id:1704133276" ridentifier 1704133276

                                    and with BLOCK:

                                    [2.7.2-RELEASE][root@router02.urs.lan]/root: pfctl -vvsr | grep "33276"

@177 block drop in log quick on igb2.20 inet all label "USER_RULE" label "id:1704133276" ridentifier 1704133276
                                    johnpozJ 1 Reply Last reply Reply Quote 0
                                    • johnpozJ
                                      johnpoz LAYER 8 Global Moderator @m0urs
                                      last edited by

                                      @m0urs not sure what your looking at exactly - but those rules block and only syn..

                                      block.jpg

                                      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 24.03 | Lab VMs 2.7.2, 24.03

                                      m0ursM 2 Replies Last reply Reply Quote 0
                                      • m0ursM
                                        m0urs @johnpoz
                                        last edited by

                                        @johnpoz

                                        Notice the "flag s/s" in your blocking rule?

                                        Compare it with my blocking rule above, which is missing that ...

                                        So I guess that is the reason, why it is not working for me.

                                        If I change the rule to "PASS" then the "flag s/s" is added. If I change it back to "BLOCK", it is missing!?

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                                        • m0ursM
                                          m0urs @johnpoz
                                          last edited by

                                          @johnpoz Ok, I think I need to set that rule to protocol "TCP" and not "ANY". In this case the "flag s/s" is added. I will try again an recreate the rules.

                                          johnpozJ 1 Reply Last reply Reply Quote 0
                                          • johnpozJ
                                            johnpoz LAYER 8 Global Moderator @m0urs
                                            last edited by

                                            @m0urs yeah tcp is what has syn.. so that is prob a requirement

                                            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 24.03 | Lab VMs 2.7.2, 24.03

                                            m0ursM 1 Reply Last reply Reply Quote 0
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