Hey Laurent, On Thu, Apr 21, 2016 at 3:27 AM, Laurent Dumont <admin@coldnorthadmin.com> wrote:

Hi,

We are running a small-ish LAN event in Toronto where we have to use a single IP address to NAT between 250-350 players. I have been made aware of possible issues with different services like Steam, Origin and Twitch who can run into issues when a large number of connections seem to originate from a single IP address. I just wanted to poke the list to see if anyone can chime him on their experiences with NATing customers and the impact it might have on public services. I am usually using public IP address space for players when designing most large LAN events. Dealing with NAT for a medium-ish amount of customers is not something I am used to do.

My $Dayjob run big LAN party events in the UK. We mostly run public v4/v6 to players for the issues you identified, however we have previously NATed our exhibitions and selected chunks of machines for various reasons and have never really come across any issues. I would say that the most I have NATed is around 50 machines, so I can't say for certain that 250-300 will be OK, but in my experience I've not seen any issues with Steam / Origin. Things I would watch out for are specific games, things like LOL and Runescape tend to have their own numbers of players per public v4. Is it only a single IP you have? If you could get any more you could NAT overload chunks of people to different IP addresses limiting your login pool size? The main issue we see with these big CDN services is bandwidth - lots of people getting to the LAN and updating all their games! Not sure how much you struggle with this, but if you do, check out - https://github.com/multiplay/lancache. Hope this helps! Tom

I do the network for a few lan parties. Last year we had 400+ people on 3 IPs and didn't have any issues. I don't think those services are that picky anymore since the rise of CGN. Just a side thing, but my advice is to look into setting up a lancache server for Steam. -----Original Message----- From: NANOG [mailto:nanog-bounces+steve.mikulasik=civeo.com@nanog.org] On Behalf Of Laurent Dumont Sent: Wednesday, April 20, 2016 8:28 PM To: nanog@nanog.org Subject: CDN, Steam, Origin and NAT. Hi, We are running a small-ish LAN event in Toronto where we have to use a single IP address to NAT between 250-350 players. I have been made aware of possible issues with different services like Steam, Origin and Twitch who can run into issues when a large number of connections seem to originate from a single IP address. I just wanted to poke the list to see if anyone can chime him on their experiences with NATing customers and the impact it might have on public services. I am usually using public IP address space for players when designing most large LAN events. Dealing with NAT for a medium-ish amount of customers is not something I am used to do. It feels silly to worry about that when you assume that WISP sometimes(mostly?) use CGN when providing internet to customers. The same could be said of most large office buildings around the world. I appreciate any input on the matter! Thanks Laurent