Game servers on one network with many VLANs:



  • Hello pfSense community.

    I am looking forward to extolling the virtues and capabilities of pfSense in a little over a month and a week at an annual LAN event, and have a couple kinks to work out before I get there.

    At the moment our LAN event is going to host several game servers, and the game servers are going to be in VLAN 3 which has the ip space of 192.168.3.0/24.

    The clients will be in many other VLANs (for monitoring purposes as well as visibility during the event), in this single example that I have I am part of the staff VLAN 6 so my IP address is 192.168.6.2 (in the 192.168.6.0/24 network).

    The hitch I have right now, is when someone opens up Steam and they look for LAN servers (lan tab if you're familiar with it), the application sends out a bunch of UDP packets to 255.255.255.255 (broadcast) looking for a server on its network…..

    ....so what I'm wondering is...how would I go about forwarding that traffic from VLAN {6 9 10 20 30 40 50 60 70 80 90 100 110 and 120} into VLAN 3 so that the server can seemingly reply back with its unicast traffic to the individual participants?

    If I can add any additional information, please let me know - I'd really like to be able to make this magic happen for the ease and entertainment of everyone at the party. :-)

    Thanks again.

    Quick reference of what happens on the same network/subnet/VLAN (client is 192.168.3.100, and server is 192.168.3.104):



  • isn't the point of VLAN to avoid broadcasts? definitely the point of routing though right?
    If you want auto discovery of the game, then you will probably just need to create a large single LAN (like 192.168.1.0/22 or something).
    Otherwise you are going to have to setup netcat listeners to forward broadcasts from one subnet to the other. Perhaps a bridge would do what you need … just don't know.

    would posting static IPs or utilizing DNS names work better than auto discovery when using VLANs with routing and FW?

    anyone else ... just my $0.02.


  • Rebel Alliance Global Moderator

    exactly - guess you could forward the broadcast via a proxy, there was something in the forum about a udp-proxy someone wrote.  There is the igmp proxy that is part of pfsense.  But have never needed to play with it, don't think it does standard broadcast??  Only multicast stuff??

    Vs searching for a LAN server, which your not really doing since the servers are not on your lan ;)  Wouldn't you want to connect to specific internet server via its IP on the 192.168.3?  Sure dns would help with this maybe nameofgame.domain.tld you could setup on pfsense to resolve..  This way users wouldn't have to use the IP.  You could post these on a website, etc.

    Here is that thread about the udp-proxy
    http://forum.pfsense.org/index.php/topic,15569.msg81508.html#msg81508



  • I think I'm in an okay position on that front. I'll look into the udp proxy. I was just hoping for something as simple as what iptables has in so far as a forwarding chain that would psuedo look like:

    (on all vlans) if destination is 255.255.255.255 and protocol is udp then forward those packets to the 192.168.3.0/24 network….

    We're going to have a captive portal setup, so that people understand a little about our setup, and then redirect to an internal website with all of the game servers and their IPs as well...but people are creatures of habit, and lazy, so having the servers appear in the LAN tab for steam based games would be a huge boon to the event.


Locked