LAN Alias Addresses



  • I am trying to place a hosting cluster behind pfSense, I am not using NAT. The problem I am having is, the cluster has 3 subnets assigned to it, they cannot be consolidated and VLANing definately will not work since any given server may have IPs from one or more of the subnets. What I really need to do is add alias IP's for the LAN interface so it responds as the the three gateways (this is how the VLAN on our 3550's handle it now, a VLAN interface has the three gateway IP's and routing is handled by EIGRP).

    Is there some way to mimic this behaviour or to insert a config script  into pfSense so that the aliases are not lost durring a reboot?  I tested the setup using ssh to add the alias, and firewall rules work just fine.

    My intended setup:
    Public WAN IP where all public LAN subnets are routed to.
    Three public LAN subnets (two /23's and one /22) on one shared VLAN used by 26 servers.
    Most of the web servers have their primary IP in one subnet with additional IP's from another subnet.

    WAN x.x.107.2/27  -> pfSense -> LAN x.x.120.1/22, x.x.118.1/23, x.x.116.1/23 -> Server Cluster

    I am running version 0.94.10 of pfSense.



  • I played with it and found a simple solution.  I added a script to /usr/local/etc/rc.d named lan_alias.sh, did chmod to 755 on the script, and rebooted.

    Script contents:
    #!/bin/sh

    case "$1" in
    start)
          ifconfig em0 inet x.x.118.1 netmask 255.255.254.0 alias
          ifconfig em0 inet x.x.116.1 netmask 255.255.254.0 alias
          ;;
    stop)
          ;;
    esac


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