Load balancing - round-robin / random

  • Is pfsense doing round-robin or random load balancing?

    Does it pass outgoing traffic on both interface ? If I am loadbalancing two T1 will a speed test give me 3mbit ?


  • Check the FAQ and wiki for pfSense.

    LoadBalancing will NOT double your speed. It will double your bandwidth.

    A simpler way to see it…
    You are adding more water pipes to your water tank, not making the water flow faster.

    This is useful if you have lots of clients on the LAN side with hefty bandwidth hogging
    applications. (Otherwise, you would use QoS to enforce how much they can consume).

  • It uses roundrobin.

    You can have 3 mbi/s with that but not with a single download. If your client downloads from multiple sites with multiple connections you'll get 3 mbit.

    Example: at the same client downloading pfsense embedded image from mirror 1 and live cd from mirror 2:

    1.5 mbit/s from download mirror 1 (wan1 maxed out)
    1.5 mbit/s from download mirror 2 (wan2 maxed out)
    =3 mbit/s over all

  • Thank you very much.

  • OK two more questions :)

    Can i use QoS on both interface. OPT and WAN?

    Traffic seems to go only on the OPT interface. I've tried downloading multiple file on different PC from different server but the traffic was sent only to OPT.


  • @charles.regan:

    Is pfsense doing round-robin or random load balancing?

    Round robin.


  • The trafficshaper currently only works at two interfaces, so the answer is no (atm).

    Are your WANs both static with static gateways? The loadbalancer needs static gateways. Did you create a gatewaypool and changed your rules to use the pool instead of one dedicated gateway?

  • Yes two different gateway. I've created a pool with both gateways. Firewall rules pointing to loadbalancing pool.

    WAN – T1 (IP Gateway:
    OPT1 --- Cable (IP Gateway:

    I have a big problem with load balancing and host on the same subnet as OPT1.
    All hosts that are with the same ISP and on the same subnet (OPT1 Cable) can't access my NATED server on my WAN T1 ?!?!
    I have a server (DNS server, WEB Server, FTP server) behind pfsense with NAT port forwarding rules

    I need to disable OPT1 and loadbalancing so these hosts can access my server.

    Here is the firewall log.....
    Dec 4 22:36:27 WAN TCP

    Why is it trying to access my server with it's internal ip address ?

    Can anybody help me figure this out
    Thanks alot.

  • Ok. Dual WAN Config:

    WAN: /29
    OPT: /26

    Client : /26
    Can't access NATed server on WAN . Blocked by firewall.

    Firewall is saying:

    What's wrong!

  • 170212 rule 10/0(match): block in on rl1: > ICMP echo request, id 512, seq 59649, length 40

    If I put OPT interface DHCP, IP address is /24, and it work.
    If I put OPT interface Static, IP address is /26, doesn't work.

    help me please