Problem...Graph Shows Traffic Crossing VLANs



  • I'm not sure what's going on here, but it appears that I have traffic from one VLAN going over into another when I have rules in place to segregate them. It seems to do this every once in a while. I can restart the system and it goes back to normal.

    LAN1 vs LAN3.jpg

    VLAN1 is my management VLAN. It only has switches, access points, etc on it. Here are the rules I have in place, blocking any protocol from LAN1 to LAN3.

    LAN1 RULES.jpg

    VLAN3 is my security VLAN. It has one computer running Blue Iris and multiple cameras. Here are the rules I have in place for LAN3, but I also have block any protocol from LAN3 to LAN1.

    LAN3 RULES.jpg

    There's no physical connection between the VLANs other than a POE switch that I'm using for the cameras has a VLAN1 address for it's management interface. Any idea what's going on?



  • @ARAMP1 said in Problem...Graph Shows Traffic Crossing VLANs:

    There's no physical connection between the VLANs other than a POE switch that I'm using

    Any chance it's a TP-Link switch?


  • LAYER 8 Global Moderator

    What specific interfaces are those rules on? Your 2nd pic shows a rule with vlan5 as source and rule with vlan3 as source - how would that ever happen? Is that interface a transit network? Then why would pfsense know about the vlans - it would just be aliases you could use for the downstream networks. But those are nets, so that means pfsense has interfaces in those networks.

    How about you actually draw up how you have this setup and what would be routing between networks here... Because those rules make no sense. If pfsense was just a transit for downstream networks (vlans).. Why would it be routing between them, etc..

    If pfsense is connected to these vlans and routing between them... It would be impossible to vlan 5 and vlan 3 as source networks on an interface for rules..

    Rules are evaluated as traffic enters an interface from the network the interface is connected to, top down, first rule that trigger wins and no other rules are evaluated..

    If that is Lan3 interface - how in the world would ever see source of vlan5?



  • @JKnott said in Problem...Graph Shows Traffic Crossing VLANs:

    @ARAMP1 said in Problem...Graph Shows Traffic Crossing VLANs:

    There's no physical connection between the VLANs other than a POE switch that I'm using

    Any chance it's a TP-Link switch?

    It's a Netgear GS728TP and the only port they share is the tagged trunk port.

    Switch VLAN.jpg



  • @johnpoz said in Problem...Graph Shows Traffic Crossing VLANs:

    What specific interfaces are those rules on?

    The first picture is the rules for VLAN1 and the last is for VLAN3.

    Your 2nd pic shows a rule with vlan5 as source and rule with vlan3 as source - how would that ever happen? Is that interface a transit network? Then why would pfsense know about the vlans - it would just be aliases you could use for the downstream networks. But those are nets, so that means pfsense has interfaces in those networks.

    How about you actually draw up how you have this setup and what would be routing between networks here... Because those rules make no sense. If pfsense was just a transit for downstream networks (vlans).. Why would it be routing between them, etc..

    If pfsense is connected to these vlans and routing between them... It would be impossible to vlan 5 and vlan 3 as source networks on an interface for rules..

    Rules are evaluated as traffic enters an interface from the network the interface is connected to, top down, first rule that trigger wins and no other rules are evaluated..

    If that is Lan3 interface - how in the world would ever see source of vlan5?

    VLAN5 is my main home network (desktops, laptops, etc). That rule is there to allow all traffic from VLAN5 to access VLAN3. I have that in place so I can access cameras and clip storage on my Blue Iris computer from my main network computers.

    Now that you point it out and I just checked, I have the same rule under VLAN5, so I just deleted it.

    But either way, it's VLAN1 that I'm wondering about and why it every so often will randomly mirror VLAN3 in the traffic graph. I just reset pfSense and it's back to normal.


  • LAYER 8 Global Moderator

    @ARAMP1 said in Problem...Graph Shows Traffic Crossing VLANs:

    That rule is there to allow all traffic from VLAN5 to access VLAN3

    Doesn't work that way!!! If you want vlan 3 to talk to vlan 5, then the rule would be on vlan 3 interface with vlan 5 ad the dest.. Vlan 5 could never be a source into vlan 3 interface.


  • LAYER 8 Netgate

    And what are you trying to do with the pass rules for ! CAMERAS?

    Put the reject rule for source CAMERAS above those and just pass to any after that.

    But either way, it's VLAN1 that I'm wondering about and why it every so often will randomly mirror VLAN3 in the traffic graph. I just reset pfSense and it's back to normal.

    Something on LAN3 sending to something on LAN1? If the port matches the Allowed_OUT_Ports_WAN alias, it will be passed to LAN1 destinations because you are not blocking those.



  • how can put this .



  • @johnpoz said in Problem...Graph Shows Traffic Crossing VLANs:

    @ARAMP1 said in Problem...Graph Shows Traffic Crossing VLANs:

    That rule is there to allow all traffic from VLAN5 to access VLAN3

    Doesn't work that way!!! If you want vlan 3 to talk to vlan 5, then the rule would be on vlan 3 interface with vlan 5 ad the dest.. Vlan 5 could never be a source into vlan 3 interface.

    Yeah. I actually had the same rule over in VLAN5's rules. I went ahead and deleted it under VLAN3. Appreciate you pointing it out.



  • @Derelict said in Problem...Graph Shows Traffic Crossing VLANs:

    And what are you trying to do with the pass rules for ! CAMERAS?

    All the pass rules for for invert match CAMERAS, so it should pass those rules for everything but the cameras, correct? Basically, I want to allow my Blue Iris computer to access to WAN and DNS without allowing the cameras.

    The only pass rule I have for the whole net is for port 123 to allow the cameras to have access to NTP.

    Put the reject rule for source CAMERAS above those and just pass to any after that.

    I'll rewrite.

    But either way, it's VLAN1 that I'm wondering about and why it every so often will randomly mirror VLAN3 in the traffic graph. I just reset pfSense and it's back to normal.

    Something on LAN3 sending to something on LAN1? If the port matches the Allowed_OUT_Ports_WAN alias, it will be passed to LAN1 destinations because you are not blocking those.

    Looking at my Allowed_OUT_Ports_WAN alias list now. Thanks.


  • LAYER 8 Global Moderator

    Its real simple to figure out what will pass and what will not..

    You know the source, you know the dest and port..

    Walk down your rules from the top on the interface the source is going to first hit pfsense on.. So vlan 3 device, on vlan 3, if vlan 1 device then vlan 1..

    To down walk through your rules.. First rule to trigger wins, no other rules are evaluted.. If you get through all the rules - and nothing passed it then the the default deny will block it.

    Your inverse camera rules, the top 3 have zero hits on them..

    Seems odd to be honest that you let cameras do anything your 5th rule, but non cameras can only go use specific ports and dns?



  • @Derelict said in Problem...Graph Shows Traffic Crossing VLANs:

    Put the reject rule for source CAMERAS above those and just pass to any after that.

    Maybe I'm not looking at this right. Will this work for my first rule? Block cameras from all except port 123.

    Camera Rules.jpg

    Might need to set this aside for a bit and then come back to it.


  • LAYER 8 Netgate

    Don't check invert match. That checkbox is, in my opinion, almost never the proper solution and there is almost always a more positive, easier to understand rule set that can be created.



  • How do I block everything except NTP? Use two separate rules?


  • LAYER 8 Netgate

    pass NTP. Block everything else.


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