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

    ["solved"] IGMP w options blocked on lo0 interface, filling the log, can't be silenced

    Scheduled Pinned Locked Moved Plus 25.03 Develoment Snapshots
    38 Posts 5 Posters 816 Views
    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.
    • L
      louis2 @johnpoz
      last edited by louis2

      @johnpoz

      John we had that discussion before. But two things here (also see Sevire issues related to IGMP multicast traffic)

      • pass rules without logging should never ever become block rules with logging
      • and yep despite that an knowing this completely wrong behavoir I did put a rule in front of other rules WITH options set, but even that does not help !!!
      • and apart from that what really happens is completely unclear!

      So .... really nothing is behaving here like it should !!

      205d2959-1d7e-49d7-aad8-9c74b48220b4-image.png

      The title in the bar is not completely valid, but that is not important here. (example copied from my pclan ruleset)

      johnpozJ dennypageD 2 Replies Last reply Reply Quote 0
      • johnpozJ
        johnpoz LAYER 8 Global Moderator @louis2
        last edited by

        @louis2 and what cidrs do you in that alias? I take it you have ip options selected in that rule? since see the gear on it. If it includes the multicast destinations being sent, then I agree that shouldn't log.

        I also agree that blocking on an allow rule especially if any any rule is bit odd, and can be confusing. if the ip options doesn't match the allow rule - then it should fall through and be logged by default deny.

        If have any any, with ip options not allowed - and traffic has ip options the traffic should just not match and fall through.

        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

        1 Reply Last reply Reply Quote 0
        • dennypageD
          dennypage @louis2
          last edited by dennypage

          @louis2 The important thing to keep in mind is that you must have allow IP options set in the rule if you expect it to match a packet with the router alert flag set.

          Suggest an “Allow” from all rule for IPv4/IPv6 and protocol IGMP on the “Local” interface.

          1 Reply Last reply Reply Quote 0
          • stephenw10S
            stephenw10 Netgate Administrator
            last edited by

            Yup the change in behaviour there is confusion I agree. It logs on whatever matched the traffic, even if that was pass rule, if IP options are no allowed. This is the correct behaviour now, it was broken for years!

            See: https://redmine.pfsense.org/issues/15400

            L 1 Reply Last reply Reply Quote 1
            • L
              louis2 @stephenw10
              last edited by louis2

              @stephenw10

              IMHO the behavoir is fully incorrect! But apart from that I have options set.

              0a1fdc4f-d979-49d2-8918-923b7cbd027b-image.png

              Also see part of my rule stack higher up.

              Note I am running pfSense+ latest beta

              1 Reply Last reply Reply Quote 0
              • stephenw10S
                stephenw10 Netgate Administrator
                last edited by

                But what's in your MulticastMediaServer alias? Since it's matching the default LAN rule below that.

                johnpozJ 1 Reply Last reply Reply Quote 0
                • johnpozJ
                  johnpoz LAYER 8 Global Moderator @stephenw10
                  last edited by

                  @stephenw10 exactly - asked the same question, just because you clicked off ip options, and want this media server(s) to see this traffic doesn't mean that rule actually matched if you put in the servers actual IP address, vs the multicast addresses..

                  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

                  L 1 Reply Last reply Reply Quote 0
                  • L
                    louis2 @johnpoz
                    last edited by

                    @johnpoz

                    cea17369-128e-4118-8882-f8ccec325f8d-image.png

                    johnpozJ 1 Reply Last reply Reply Quote 0
                    • dennypageD
                      dennypage
                      last edited by dennypage

                      IGMP should be allowed to all.

                      Try this rule on the “Local” interface:

                      4ffeb9b5-1733-472f-938f-e9f84d340e49-image.png

                      db9fc9c3-34c0-44f5-a8e7-c490c02eefe2-image.png

                      1 Reply Last reply Reply Quote 0
                      • johnpozJ
                        johnpoz LAYER 8 Global Moderator @louis2
                        last edited by johnpoz

                        @louis2 well that last one is wrong.. its 239.255.255.250

                        so yeah its still going to log that traffic as blocked.

                        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

                        L 1 Reply Last reply Reply Quote 0
                        • L
                          louis2 @johnpoz
                          last edited by louis2

                          @johnpoz said in ["solved"] IGMP w options blocked on lo0 interface, filling the log, can't be silenced:

                          239.255.255.250

                          John you are right, I should have added that address. The problem is that '239.255.255.0' is a range not an address. I do not know the exact usage of 239.255.255.250 however it is a used control address.

                          However, adding that address does not solve the problem. Below a small part of my actual log

                          At this particular moment the log shows 244.0.0.1 Note that the shown rule set was already in place when created the picture of the log somewhat higher (showing addresses being filtered)

                          181bbf34-d0d7-4489-a710-55ace636f94a-image.png

                          PIMD not yet working properly, could be due to the fact that I did not recompile it yet for FreeBSD15 current, but I am not sure about that.

                          Next to that I really and fully stick to my vision that rules should do what they say what they do !!!

                          Not logging pass rules turning in block rules and start logging ....... terrible ...

                          Rules affecting traffic not selected by that rule .... terrible

                          I really really can not accepted that as being OK !!

                          1 Reply Last reply Reply Quote 0
                          • stephenw10S
                            stephenw10 Netgate Administrator
                            last edited by

                            You have that rule duplicated on both those interfaces?

                            L 1 Reply Last reply Reply Quote 0
                            • L
                              louis2 @stephenw10
                              last edited by

                              @stephenw10

                              No, I had it only enable on the PCLAN, since it is still in an experimental stage. However I see the behavoir on multiple vlans including the PCLAN.

                              I did add the rule now to the guest vlan and my privileged vlan as well. To keep them equal, not that I expect it to change something.

                              1 Reply Last reply Reply Quote 0
                              • stephenw10S
                                stephenw10 Netgate Administrator
                                last edited by

                                Are you adding it as a floating rule? It doesn't look like that but...

                                1 Reply Last reply Reply Quote 0
                                • dennypageD
                                  dennypage
                                  last edited by

                                  The rule to allow IGMP must come before the default rule you have at the end of the interface. The log entries you posted show that this is not the case.

                                  You can either use a floating rule with quick, or you can use Local. Try what I showed above. You can tighten it up later if you feel the need, but get it working first.

                                  L 1 Reply Last reply Reply Quote 0
                                  • L
                                    louis2 @dennypage
                                    last edited by

                                    @dennypage @stephenw10

                                    To answer your questions

                                    Floating
                                    No it am not using floating rules here. In short I only use floating for reasons of security or high performance.

                                    Rule position
                                    There are a couple of things which determs the order I place rules. In short

                                    • security
                                    • performance
                                    • logic

                                    Below the first part of my rule set as related to my PCLAN

                                    3fca7c78-0a26-4ae9-865c-5a6add82f1ce-image.png

                                    dennypageD 1 Reply Last reply Reply Quote 0
                                    • dennypageD
                                      dennypage @louis2
                                      last edited by

                                      @louis2 have you tried the simple Local rule that I posted?

                                      L 1 Reply Last reply Reply Quote 0
                                      • L
                                        louis2 @dennypage
                                        last edited by

                                        @dennypage

                                        Do you refer to
                                        ^suggest an “Allow” from all rule for IPv4/IPv6 and protocol IGMP on the “Local” interface.^

                                        No I did not yet but that rule is much wider than I like, and why should that make a difference !!???

                                        Never the less I will add the rule for now for the PC-lan. However what ever the result is, I will remove it later on !! 🙄

                                        a4ec691f-c694-45b3-bde6-7099bd31496d-image.png

                                        1 Reply Last reply Reply Quote 0
                                        • dennypageD
                                          dennypage
                                          last edited by

                                          Yea, there really is no need/reason to restrict IGMP in the local network. Especially if you are actually using IGMPv3.

                                          Btw, your comments indicate IGMPv3, but are you actually using v3? And joining toward a specific source? IGMPv2 is much more common as a default, and many devices and software do not implement v3 correctly. FWIW, unless you really know what you are doing with multicast, and really need v3 due to the number of available/conflicting sources, you should stick with v2.

                                          YMMV.

                                          L 1 Reply Last reply Reply Quote 0
                                          • L
                                            louis2 @dennypage
                                            last edited by

                                            @dennypage

                                            NOP ! 😖 😖

                                            2b6655ad-0579-4a77-a70a-fbd1811df842-image.png

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