Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I've done a search here and wasn't able to find anything relevant to my situation. I apologize in advance if I've missed an existing post on the topic.

Our ISP has provided us with 6 static IP addresses. We are currently using two of them (plus one for the Comcast-provided router). One of the static addresses routes to our internal network, and the other goes to our VOIP phone system. Unfortunately, the Comcast machine doesn't support QoS, so our VOIP calls have been choppy.

We plan to put the Comcast-provided router into bridge mode and replace it with an ASUS RT-N16 running DD-WRT. However, I'm unsure how to set up DD-WRT to function similarly to our existing Comcast router. The Comcast router's WAN IP is the first of our static IP addresses. We did not need to provide an internal LAN IP address — simply connecting machines that use our other public addresses to the LAN ports on the Comcast router is enough for it to route between the connected machines and our internet connection.

Is there a way to do a similar setup through the DD-WRT?

Thanks in advance.

share|improve this question

I am not sure how to do it on dd-wrt, but that is Linux-based so this should certainly be possible. See if you can go with a proxy arp. Basically you will be putting your /29 subnet on both the inside and outside adapters.

share|improve this answer

Do you or do you not want private addressing? The simple solution here is to use a switch, instead of a router. Be sure each host is properly firewalled. I myself would rather use a proper hardware firewall to protect my network, have it proxy ARP the other addresses and setup static NATs to each host. DD-WRT may be able to do this, not sure.

share|improve this answer
No private addressing, if at all possible. We would like the machines with public addresses to actually have the public addresses. We need a router instead of a switch here, because we need to prioritize VOIP traffic from one of the public machines with QoS. – Stephen Touset Mar 14 '11 at 20:11
Seems to be on the DD-WRT wiki that setting QoS is pretty simple, but you're also after what setting to put this device in to basically bridge the outside to the inside. I believe it can do this and still meet your requirements, you'd have to test it. – SpacemanSpiff Mar 14 '11 at 23:00

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.