I have a Linksys WRTL54GL running the opensource firmware DD-WRT and have been quite happy with this up until recently. A short while back I upgraded my Internet connection to a 50/50 mbit and then the problems started. It turned out that the Linksys WRTL54GL can’t route much more than 30/30 mbit on the WAN side.
This means that even though the computers on the LAN side could easily talk to each other with 100/100 mbit through the internal switch I could not connect to the Internet with more than 30/30 through the router. As I researched the marked I discovered two things: firstly, it was hard to find information on the WAN side speedlimit on the product spec sheets and secondly that the few that I found was capable was expensive (>1500 DKK). This page does actually list the WAN side speeds:Router Charts [smallnetbuilder.com]
At my work I had the option to buy a old retired Thinkpad T42 cheaply and I had and an old PCMCIA netcard lying around, so I figured I might as well put a router together myself using CentOs. I am aware that there are many router distributions available, see en.wikipedia.org/wiki/List_of_router_or_firewall_distributions, but I work with RHEL and CentOS daily and would like the freedom of not using a dedicated distribution.
I have a picture of the services that the new router should be able to do manage. This is really not very demanding as I already have another server running NFS, CIFS, SSH, WWW any many other services. This could of course also have been done on my existing server but I found it more pleasing to have the router separated from sever that hosts data.
- Route WAN side with 100/100 mbit.
- Provide NAT (IP masquerading) for the clients on the LAN side.
- Serve as a local caching DNS server.
- Serve as a local DHCP server.
- Serve as a statefull firewall for my LAN.