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

    Prevent some LAN devices from being accessable over L2TP/IPsec

    Scheduled Pinned Locked Moved Firewalling
    43 Posts 3 Posters 9.4k 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.
    • DerelictD
      Derelict LAYER 8 Netgate
      last edited by

      Read the language in the documentation again:

      Firewall traffic blocked outbound

      If the firewall logs show traffic blocked "out" on L2TP, then add a floating firewall rule to work around the block:

      Navigate to Firewall > Rules, Floating tab
          Click "+" to add a new rule
          Set 'Action to Pass
          Check Quick
          Select L2TP VPN for the Interface
          Set Direction to Out
          Set Protocol to TCP
          Set Source/Destination as needed, or set to any
          Advanced Features:
              Set TCP Flags to Any flags
              Set State Type to Sloppy State

      You should then control what your L2TP VPN clients can connect to with rules on your L2TP VPN tab.  if you only want them to get at TCP/UDP 53, TCP/80, and TCP/443 put those pass rules there.  Everything else will be blocked as it enters the firewall from the clients.  Except that it doesn't work.

      I just tested it.  The floating rule is exactly as described above.  Direction OUT on L2TP VPN verified.  It appears the rules on the L2TP VPN tab are ignored.  Yes, I cleared states.

      I can still SSH to 172.26.0.100 and the source address is the VPN client address 172.29.7.128.

      ![Screen Shot 2015-05-23 at 10.32.20 AM.png](/public/imported_attachments/1/Screen Shot 2015-05-23 at 10.32.20 AM.png)
      ![Screen Shot 2015-05-23 at 10.32.20 AM.png_thumb](/public/imported_attachments/1/Screen Shot 2015-05-23 at 10.32.20 AM.png_thumb)
      ![Screen Shot 2015-05-23 at 10.31.10 AM.png](/public/imported_attachments/1/Screen Shot 2015-05-23 at 10.31.10 AM.png)
      ![Screen Shot 2015-05-23 at 10.31.10 AM.png_thumb](/public/imported_attachments/1/Screen Shot 2015-05-23 at 10.31.10 AM.png_thumb)
      pfSense+L2TP.png
      pfSense+L2TP.png_thumb

      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)

      1 Reply Last reply Reply Quote 0
      • D
        doktornotor Banned
        last edited by

        Yeah, of course they will get ignored when you tick the "Quick" checkbox on the floating rule.

        1 Reply Last reply Reply Quote 0
        • DerelictD
          Derelict LAYER 8 Netgate
          last edited by

          Direction OUT.  The SSH connection is coming IN.

          So you're saying the wiki is wrong?

          https://doc.pfsense.org/index.php/L2TP/IPsec

          And the floating rule is for TCP only.  I can still ping 172.26.0.100 despite the reject rule.

          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)

          1 Reply Last reply Reply Quote 0
          • D
            doktornotor Banned
            last edited by

            Sigh…

            1/ Check what sloppy state does.
            2/ Check the Set Source/Destination as needed - why on earth are you setting that as ANY when it obviously is NOT suitable for the intended purpose???

            1 Reply Last reply Reply Quote 0
            • DerelictD
              Derelict LAYER 8 Netgate
              last edited by

              Because without it set to ANY reply traffic to sides is blocked outbound.  This is with the rule disabled:

              ![Screen Shot 2015-05-23 at 10.57.25 AM.png](/public/imported_attachments/1/Screen Shot 2015-05-23 at 10.57.25 AM.png)
              ![Screen Shot 2015-05-23 at 10.57.25 AM.png_thumb](/public/imported_attachments/1/Screen Shot 2015-05-23 at 10.57.25 AM.png_thumb)

              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)

              1 Reply Last reply Reply Quote 0
              • DerelictD
                Derelict LAYER 8 Netgate
                last edited by

                The bottom line is rules on the L2TP VPN tab do not work like they work on every other VPN interface in pfSense.  They do not filter traffic coming INTO the firewall from VPN clients at the other end of the tunnel.

                For instance, with the floating rule disabled I can still ping 172.26.0.100 despite the explicit block rule on L2TP VPN.

                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)

                1 Reply Last reply Reply Quote 0
                • D
                  doktornotor Banned
                  last edited by

                  I am not telling you to disable the rule. I am telling you to "Set Source/Destination as needed". When access to LAN in unwanted, obviously ANY is not proper?!?!?!?!?!?!?!?!?

                  1 Reply Last reply Reply Quote 0
                  • DerelictD
                    Derelict LAYER 8 Netgate
                    last edited by

                    Explain how, with this explicit block rule, L2TP clients can ping 172.26.0.100.  The floating rule only applies to TCP traffic anyway so enabled or disabled makes no difference.  Let's forget about TCP and concentrate on ICMP.

                    ![Screen Shot 2015-05-23 at 11.09.45 AM.png](/public/imported_attachments/1/Screen Shot 2015-05-23 at 11.09.45 AM.png)
                    ![Screen Shot 2015-05-23 at 11.09.45 AM.png_thumb](/public/imported_attachments/1/Screen Shot 2015-05-23 at 11.09.45 AM.png_thumb)

                    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)

                    1 Reply Last reply Reply Quote 0
                    • DerelictD
                      Derelict LAYER 8 Netgate
                      last edited by

                      All rules on LT2P VPN tab disabled
                      Floating sloppy rule disabled
                      Only rule on IPsec tab passes UDP 1701 to WAN address
                      States cleared

                      Can still ping 172.26.0.100 from L2TP clients.

                      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)

                      1 Reply Last reply Reply Quote 0
                      • D
                        doktornotor Banned
                        last edited by

                        Check stuff like pfctl -sr, pfctl -ss and go from there. I have zero desire to dig into the code generating god knows what rules behind the scene, let alone to set up this nonsense here. IPsec alone is flaky like hell here with the strongswan POS, no need to add another level of crap into the mix. There's also this "Disable Auto-added VPN rules" checkbox in System - Advanced - Firewall.

                        Perhaps start your own thread, debugging your ICMP is really not what's this thread about.

                        1 Reply Last reply Reply Quote 0
                        • DerelictD
                          Derelict LAYER 8 Netgate
                          last edited by

                          Nice hang time on that punt. Maybe before belittling and insulting people next time you take a step back.

                          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)

                          1 Reply Last reply Reply Quote 0
                          • B
                            BigApple
                            last edited by

                            well thank you for trying to help … maybe best I pay the guys to get help ...

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