Two LAN gateways on same subnet ?



  • What I'm trying to do:
    10.0.0.2/24 - phone gateway on EM1

    10.0.0.1/24 - data gateway on EM2

    Pfsense will not let me add 10.0.0.1 interface since it's in the same subnet as the other gateway.  What is the best resolution to this (virtual IP?)?  We are set to replace the original firewall at 10.0.0.1 with the new pfSense firewall and need to be able to have both these as gateways on the box.

    More notes that may or may not be useful.
    I am doing dual wan, but no fail over or loadbalancing.  I have the phones aliased in a rule to only go over the 'phone' gateway (cable modem). 
    The 10.0.0.1 interface will be going over the other internet connection.

    Thoughts, advice and observations are appreciated.


  • Banned

    Erm… Why should it be on the same subnet? How about

    10.0.1.0/24 - LAN
    10.0.2.0/24 - phones



  • I wish. 
    It's an existing VOIP environment getting a new / update VOIP system (Jive sip trunk).  The local admin is wanting the two gateways, one for each internet connection.  The simplicity of the design should make things work well, if we can get past this one hurdle.

    We could make two networks on the same wire, but I advised against it as we do not have VLAN abilities (a few dumb switches involved).


  • Banned

    Well, you can do policy routing for a separate DHCP scope used for the phones only. (Of course, separate network or VLAN would be much preferred here.)


  • Rebel Alliance Global Moderator

    So your pfsense wan network or transit is on 10.0.0/24 what is psfense IP??  You can for sure point to different gateways on this transit network that your calling your wan..  There was recently a thread about this..

    "Pfsense will not let me add 10.0.0.1 interface since it's in the same subnet as the other gateway"

    I think your confusing terms here.. If you have an INTERFACE on pfsense that has IP address 10.0.0.1, no pfsense is not going to allow you to create another interface with IP address 10.0.0.2..  That is not a GATEWAY..

    If your running the phones and data on the same network.. And you want phones to come in and hit pfsense on .2 vs .1 - then that would just be a VIP you create on that network..

    Why are you running data and voip on the same network.. That is a BAD idea.. Your data and voip should be on different vlans plan and simple..

    You should never use more than 1 network on the same wire.. If you can not do vlans – get some vlan capable switches and do it correctly!!!