3 interfaces, 3 dhcp



  • Hello everyone,
    i've got 3 interfaces and dhcp is activated on each
    1 interface (wan)is connected to 2 isp routers and accept guest wifi access
    the other 2 are configured with static mapping for the clients.
    The 3 interfaces and the clients are linked to a switch.

    The problem is that when a client ask for an address it seems to get randomly from interfaces (could be from the guest interface or from the IP linked to its MAC or from the only free IP of the other interface).
    Is there a way to force a dhcp interface to MAC address are give a priority to an interface to resolv dhcp requests?

    Many thanks in advance if you can give me any tips.



  • @nujiel:

    i've got 3 interfaces and dhcp is activated on each

    I presume you mean you have DHCP Server enabled on all three interfaces.

    @nujiel:

    The 3 interfaces and the clients are linked to a switch.

    The problem is that when a client ask for an address it seems to get randomly from interfaces

    That is because your switch (unless there s something you haven't told us) will deliver the DHCP DISCOVER to all three interfaces and hence all three DHCP servers.

    This is an unusual configuration. Why have you chosen it?



  • because we wanted to have 2 diferent LANs sharing the internet connection with the few hardware we have. And also we wanted a guest network for people connecting to the WAP of the ISP routers.


  • LAYER 8 Global Moderator

    you are just going to have issues trying to run multiple networks over the same physical wire.

    If you have need of 2 lans, then get a switch that supports vlan - they can be had for cheap to be honest.  $100 for example for 8 port gig smart switch with vlan support.

    Or just get multiple dumb switches and multiple interfaces on the pfsense box and do a actual physical segments with dumb switches on each segment.

    I'm a bit confused about this

    "1 interface (wan)is connected to 2 isp routers and accept guest wifi access"

    So you connect into your pfsense wan interface for wifi?  This is a wireless interface?  And then your 2 isp routers are wireless connections?  Confused.

    How do you connect 2 different isp routers to 1 interface?  if you have more than 1 isp connection you would normally use multiple interfaces in pfsense as wan connections.

    with dumb switches you would do wan interface to your isp connection.

    Then for how many segments you want on the lan side you would have interfaces in pfsense connected to dumb switch.  With the clients you want on that segment connected to that switch.  And then on segment you want wireless connect AP.

    You can then control access between your segments, and internet (wan) access.  This can be done with $20 switches and $20 wireless router used as AP.  And $5 nics in your pfsense box.



  • @johnpoz:

    I'm a bit confused about this

    "1 interface (wan)is connected to 2 isp routers and accept guest wifi access"

    My guess about that was that the pfSense WAN interface AND the two ISP routers were connected to the switch (along with everything else!) and that the ISP routers were also APs that were used by "guests" and consequently the guests effectively bypassed pfSense.


  • LAYER 8 Global Moderator

    so everything was connected to the same dumb switch - both wan and lan of pfsense.

    Thats just crazy ;)



  • yes, to solve my problem i installed dhcp on a server, it has more feature than pfsense's dhcp and exactly fits my needs


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