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    SSH Idle Session Timeout/Dropping Issues

    Scheduled Pinned Locked Moved General pfSense Questions
    16 Posts 7 Posters 8.9k Views
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    • D
      doktornotor Banned
      last edited by

      +1. Never seen a session dropped beyond broken clients (like, STFP plugin for Total Commander).

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      • H
        Harvy66
        last edited by

        asymmetric routing? TCP connections have a 24 hour timeout. If it's dropping after 90 seconds, it's because the TCP handshake isn't being completed from PFSense's perspective.

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        • C
          com6056
          last edited by

          Yeah it's really weird. I don't believe it is asymmetric routing since I am just using it as a transparent bridge. Right now I only have one of our networks on it, but if I can get this working I am going to put both on it.

          ISP (X.X.49.254) -> (igb0)Firewall(igb1) -> Core Switch (X.X.49.247)
          ISP (X.X.50.254) -> (igb2)Firewall(igb3) -> Core Switch (X.X.50.247)

          In our case, the "ISP" is the college's network that we are using. This is for a single dorm floor.

          Everything on our network is using X.X.49.247 and X.X.50.247 as their gateways (depending on which they are on) and then our core switch passes it along to X.X.49.254 or X.X.50.254. Right now, only the X.X.50.0/24 network is going through the firewall. I have disabled Outbound NAT rule generation in case that had anything to do with it.

          I have now discovered that X11 forwarding seems to also kill any SSH session after maybe 5-10 seconds (Write failed: Connection reset by peer).

          I have attached my rules for WAN, LAN, and Floating rules in case they might help. LAN and WAN are interface groups that include both the 49 and 50 WAN and LAN interfaces.
          I have also tried changing the State Type for the LAN and WAN rules to "sloppy state" but that didn't help (I'm not sure if it is something that could have helped but I figured I would try it). If you need any more information that might help with troubleshooting this issue, please let me know. Thanks!

          ![LAN Rules.PNG](/public/imported_attachments/1/LAN Rules.PNG)
          ![LAN Rules.PNG_thumb](/public/imported_attachments/1/LAN Rules.PNG_thumb)
          ![WAN Rules.PNG](/public/imported_attachments/1/WAN Rules.PNG)
          ![WAN Rules.PNG_thumb](/public/imported_attachments/1/WAN Rules.PNG_thumb)
          ![Floating Rules.PNG](/public/imported_attachments/1/Floating Rules.PNG)
          ![Floating Rules.PNG_thumb](/public/imported_attachments/1/Floating Rules.PNG_thumb)

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          • C
            com6056
            last edited by

            Progress! Well kind of. If I completely disable all packet filtering (System->Advanced->Firewall / NAT-> Disable all packet filtering.), it seems to solve the problem. Could it be that "State Type" option in the rules and I am just not setting it for the correct rules?

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            • D
              doktornotor Banned
              last edited by

              @com6056:

              If I completely disable all packet filtering (System->Advanced->Firewall / NAT-> Disable all packet filtering.), it seems to solve the problem.

              Is pfSense actually doing anything useful on your network? Have hard time understanding your setup.

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              • C
                com6056
                last edited by

                Sorry, I meant that it solves the problem but isn't a valid solution since it defeats the purpose of having it on our network. I am using it at the moment with pfBlockerNG to pull in a bunch of blacklists for now and possibly use Snort at some point in the future.

                I believe I have fixed the issue though. I added a rule to Floating Rules, WAN Rules, and LAN Rules that passes the TCP protocol and in the advanced settings has the TCP flags set to "Any flags." and the State Type set to "sloppy state". The Floating Rule is being applied in the "out" direction on all interfaces but my management interface. I'm not sure if all three of the rules or what I have set in them are necessary, but the issue seems to be fixed. If it comes back up again, I will post again. Thanks for all your help! I really appreciate it!

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                • N
                  nz-devops
                  last edited by

                  I've encountered SSH timeouts every 30-40 secs but only on non-VPN connections to local servers.
                  There are no issues when the same ssh connections are made on the VPN. Isn't this odd?  I don't recall making these settings for the VPN connection.
                  I've applied Conservative in System/Advanced/Firewall&Nat section but still trying to figure out what makes the local SSH connections timeout.

                  Anyone else experienced this?

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                  • johnpozJ
                    johnpoz LAYER 8 Global Moderator
                    last edited by

                    So your not talking a ssh session to pfsesne, your talking a ssh session inbound to a server behind pfsense.  That you forward in from pfsense wan..

                    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 2.7.2, 24.11

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                    • C
                      com6056
                      last edited by

                      I was able to get it to work by adding a pass rule (I added a floating rule and a rule in both LAN and WAN) to allow for sloppy TCP states (under advanced options and set State type to Sloppy).

                      sloppy.png
                      sloppy.png_thumb

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                      • DerelictD
                        Derelict LAYER 8 Netgate
                        last edited by

                        I'd fix whatever weirdness is on my network making that necessary but that's probably just me.

                        I would at least want to understand why.

                        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)

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                        • johnpozJ
                          johnpoz LAYER 8 Global Moderator
                          last edited by

                          Guess we are just weird like that Derelict ;) hehehe  I would do the same thing.

                          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 2.7.2, 24.11

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                          • H
                            Harvy66
                            last edited by

                            @com6056:

                            Progress! Well kind of. If I completely disable all packet filtering (System->Advanced->Firewall / NAT-> Disable all packet filtering.), it seems to solve the problem. Could it be that "State Type" option in the rules and I am just not setting it for the correct rules?

                            Ahh, my young padawan, it does not solve the issue, it solves the symptom. I could tell this is what you meant with "Well kind of", but words can be important as they can influence how you think about a problem, even if you "know what you meant".

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                            • J
                              Javik
                              last edited by

                              @Derelict:

                              I'd fix whatever weirdness is on my network making that necessary but that's probably just me.

                              I would at least want to understand why.

                              Can you define what you mean by "network" weirdness, if pfSense is the cause of the problem?

                              Pardon me for jumping onto this thread, but I am experiencing the same problem, accessing a Cisco phone system on its voice VLAN 150, doing automatic routing through pfSense to VLAN 1.

                              pfSense is set as the gateway on VLAN 150 for the Cisco, and is set as the gateway for the desktop PC on VLAN 1.

                              Open SSH on VLAN 1 to the Cisco controller, and I can connect, but the connection only stays active 1-3 minutes and suddenly force-closes.

                              It kills the SSH session, even if the session is NOT idle but streaming data, such as dropping right in the middle of a "show tech-support" text dump.

                              VLAN 150 firewall config in pfSense is  "pass all IPv4, all protocols, from any to any", setting it wide open to remove any possible flow restrictions.

                              pfSense still drops SSH anyway, even though I can ping the Cisco continuously from VLAN 1, no problem.

                              If I put a computer directly on VLAN 150, SSH works normally, sessions can stay open indefinitely, no problem.

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                              • DerelictD
                                Derelict LAYER 8 Netgate
                                last edited by

                                It means "sloppy state" and "disabling pf" should never be necessary.  I am not going to try to decipher that text, do the work, and make a diagram for you.

                                Look at the diagram in my sig to see the information necessary and make one and post it.

                                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)

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