John R Pierce wrote: > On 04/24/11 11:15 AM, Timothy Murphy wrote: >>>> Without any information on what the purpose of such a setup would be, >>>> it's close to impossible to give you any recommendations. Is it >>>> because you want to use your CentOS system as a firewall? a router? a >>>> HTTP proxy? a network sniffer? >> I don't actually think my motives are relevant. >> In case I didn't described the situation clearly, >> my CentOS server is connected to an ADSL modem by ethernet (eth0). >> The modem's IP address is 192.168.1.254 . > > your goal is very relevant if youj are expecting us to suggest a > workable solution. > > but ouch, sounds like your modem is ALSO a NAT router, and is probably > running DHCP already. what IP is eth0 of this linux PC ? > > you want to avoid 'double nat' where there's multiple layers of address > translation as its just ugly as heck to troubleshoot, and adds > complexity without any additional value.. > > assuming I'm right, and your modem is in fact doing NAT routing too, > then I'd put DD-WRT or Tomato opensource firmware on the WRT54GL, > configure it for LAN only use, so all 5 ports are LAN, plug it into the > modem, plug your computer(s) into the WRT's switch also, and configure > the WRT"s wireless. now all your systems will be on that 192.168.1.xxx > subnet. He wants to pass all traffic through CentOS box so he can monitor traffic, run bandwidth shaping, etc.. As for double-NAT, it's not so horrible. I now people using even triple-NAT without issues. Not recommended, but much easier for noob's then learning how to route properly. 7 years of experience speaking. Ljubomir