1 server + 2 NICs + 2 IPs = problem

[detekt]

Hello. Im holding a game server. Recently the amount of connections became very big and I needed to upgrade my internet. Unfortunately my ISPs most expensive contract offers just 7mbit/s international upload. So I decided to do the following: Sign a new, second contract for a new IP with another 7mbit limit on it so I ended with 2 real static IPs with 7mbit bandwidth each.

My server application listens on IP 0.0.0.0 so I decided to do the following - forward half of the clients through IP1 and the other half through IP2, so both group of clients should connect to the very same gaming server and play together. After I configured the server everything went perfectly. The traffic was load balanced between the 2 IPs. That was great I had double capacity! 10 minutes later - mass lag and disconnects.

eth0 - IP: 77.70.124.69 Mask: /24
eth3 - IP: 77.70.120.121 Mask: /24

Routing Table:
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 77.70.124.1 0.0.0.0 UG 0 0 0 eth0
0.0.0.0 77.70.120.1 0.0.0.0 UG 0 0 0 eth3

When I contacted my ISP they said that my computer was spoofing addresses. With other words my server sent packet(s) via eth0 with source address 77.70.120.121 which caused my ISP router to drop the packets and cause a big mess.

Please help me I want my clients to have access to the same server application from both IPs to achieve load balancing so I will be able to host more users.



Thank you

[mzainal]

My suggestion, do load balance (UltraMonkey). That you can support huge user access your game server. Maybe you can do active/active cluster. Just use Centos server. Just my opinion.

Regards,
BaniE

[wszachau]

You haven't described how you achieve the load balancing. Do you use DNS round-robin? The obvious problem is that your machine now has two default gateways, which is never a good idea. And since both use the same metric, the routing engine can't decide which one to use.
I would seriously suggest changing ISP if they cannot offer more than 7MBit/s upload speed. You should be able to get 100MBit/s for very affordable money, even in Bulgaria. And if you can't find one, then maybe you need to host in another country or go to multiple servers.

[TaZMAniac]

Have you looked into a dual WAN router with load balancing?
Easiest way to achieve your goal.

[jayd512]

Have you looked into a dual WAN router with load balancing?
Easiest way to achieve your goal.

I agree.
While there are several methods you could employ, getting a decent dual-WAN is really going to be the simplest way, and they aren't priced to badly: Link.