I am sysadmin in an internet/gaming-café. The setup until recently (before i started) was a hardware router connecting the computers to the internet. There wasn't really any firewall solution. My plan was to exchange the hardware router with a linux-server which did the routing and firewall, dhcp, dns-server etc. We have global IP-adresses for all computers. There is a "linknet" between the router and the ISP.

I did the setup, but problem is the performance isn't good. In games (such as World of Warcraft) the ping/latency is much higher than with the hardware router. Shouldn't the linux-server be able to manage this? Is there something I have configured wrong?

Dell Poweredge 840
Dual Core Intel Xeon
2GB DDR2 667MHz
RAID: Dell SAS5/iR
2 250GB 7200rpm SATA-drives
1 onboard Broadcom NetXtreme 5721 PCI-express
1 add-on Broadcom NetXtreme 5721 PCI-express
1 add-on Intel PRO 1000PT PCI-express

Any help or suggestions would be greatly appreciatet!
Is there a better solution for doing what I want to (with the equipment mentioned)?