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

    Basic Routing Question

    Scheduled Pinned Locked Moved Routing and Multi WAN
    18 Posts 4 Posters 2.0k 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 Offline
      Derelict LAYER 8 Netgate
      last edited by

      I have noticed no difference in 2.2.4.

      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
      • T Offline
        tomwaller
        last edited by

        So given my config above, you don't think this is the asym. routing issue I've been seen mentioned on the forums? I only ask as the problem seems similar to others.

        1 Reply Last reply Reply Quote 0
        • KOMK Offline
          KOM
          last edited by

          I also run ssh and scp sessions that can last for days.  No issues at all with dropped connections.  I didn't need to twiddle any app-specific settings either.  Check your firewall logs around the time when a connection drops to see if there's anything going on.

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

            You have to be dealing with two routers to have an asymmetric routing problem.  As long as pfSense is the default gateway on both segments you should be fine.

            I haven't had to twiddle any settings in ssh/sshd either. At least not for several years.

            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
            • C Offline
              cmb
              last edited by

              From the looks of that, the 110.4 host is probably dual homed on both networks, leaving the host itself creating an asymmetric path.

              1 Reply Last reply Reply Quote 0
              • T Offline
                tomwaller
                last edited by

                Ahh, that may well be it. Yes the 110.4 host is dual homed.

                It is another FreeBSD box (NAS4Free). It has eth0 connected to VLAN110 and eth1 connected to VLAN100. It is configured to use 192.168.110.254 as it's default gateway. I suspect that is wrong then?

                1 Reply Last reply Reply Quote 0
                • T Offline
                  tomwaller
                  last edited by

                  Am I right in assuming that I don't need to have any trunked ports on my switch as I have a interface from pfSense directly connected into each VLAN segment?

                  I'm reading up about VLAN routing and most of the guides are for pfSense with single LAN interfaces.

                  1 Reply Last reply Reply Quote 0
                  • T Offline
                    tomwaller
                    last edited by

                    OK - so it definitely looks like asymmetrical routing is the issue here.

                    If I disable the second NIC attached to VLAN100 on the server I am trying to SSH to, it removes the route on that server for 192.168.100.0/24 and I no longer have an issue with SSH. Works perfectly. I can see the packets going from 192.168.100.50 (my PC) > 192.168.110.254 > 192.168.110.4 and then back along the same path as the primary NIC in the server is on the 110 VLAN with 192.168.110.254 as the default gateway.

                    Am I doing something fundamentally wrong here. I thought the packet would come back the way it entered but I guess not. Is there any way I can achieve this without losing the ability to keep both NICs on the server I want to SSH to? Ideally I want to keep them for dedicated jail usage on the seperate subnets.

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

                      In general you can use the other interfaces for same-subnet traffic but anything outside a subnet that your NAS thinks is "connected" is going to go to the default gateway unless there is a specific route for it in the NAS.

                      Your jails might be able to have a different default gateway from the main NAS routing table.  I'm not sure.

                      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
                      • C Offline
                        cmb
                        last edited by

                        @tomwaller:

                        Am I doing something fundamentally wrong here. I thought the packet would come back the way it entered but I guess not.

                        No, return traffic follows the system routing table, which means it sends it out the directly-connected network in that circumstance.

                        If you dual home a system like that, don't connect cross-subnet to it. Strictly connect to its IP on the same subnet as the source machine, or the IP of the interface where the default gateway resides if it's sourced from a network where the destination system isn't directly connected. That'll ensure no issues along those lines.

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