Bridge with filter to control broadcast

  • Hi Guys,

    I'm trying to use pfsense as a "broadcast filter" in a routed Network. It seems to work, but after a time I get some problems I can't really explain.
    If searched in the forum for a similar problem, but didn't find anything.

    Friends and co-workers which also use pfsense couldn't help me. Maybe someone from the forum could help me.

    But let's start from the beginning:

    I have managed Layer 2 switch with 3 VLANS behind a Cisco Router tagged in the 3 VLANS which routes the 3 subnets.
    Now let's say, User1 in subnet1 creates a GameServer which listen on UDP Port 5555 and User2 in subnet2 starts the ingame browser and try to find the gameserver.
    This fails because the broadcast ( DPORT 5555) isn't routed over the Cisco router.

    So I installed pfsense 2.0 disabled the WAN interface, created 3 Vlans on fxp0, connected this to the switch, enabeld filtering on bridge, disabled filtering on bridge members and created a RULE on bridge0 which allows UDP traffic from src an to dst on Port 5555. After that User2 in subnetz2 could find the gameserver in Subnet1.

    Here a short diagram for a better understanding.

          .-------+------.      VLAN2
          |  Cisco Router |    VLAN3
          '-------+------'    VLAN4
                    | tagged VLAN 2,3,4 
          |   Switch     +-----------------------+--------- 10.0.0.x/22 VLAN2 ------ User 1 Gameserver (
          '------+-------'                       |
                   |                             +--------- 10.0.10.x/24 VLAN3 ----- User 2 Game Client (
                   |                             |
                   |                             +--------- 10.0.20.x/24 VLAN4
                   | tagged VLAN 2,3,4
          |   pfSense    | <--bridge0 over fxp0_vlan2,3,4

    Now the problem: After a while (couldn't fix when) all traffic (even IP) from VLAN2 ,3, 4 want to flow over the bridge instead the router. Unplugging and plugging the FW fixes the problem for a time, but then after a time the problem appears again.

    Is this a BUG or an error in configuration? Hope somebody could help me. If you need more informations, please let me know.

    Best regards,

  • I solved the problem. Disabling CDP on the VLAN interfaces at the Cisco Router fixed the problem.

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