What does Disable NAT & Firewall actually do?

Posts: 533 · Posted: Fri Nov 04, 2005 1:21 pm Post subject:

enodo wrote:

But you begin to see the method to my madness! The only device downstream of the RTP300 in my setup is another router! So my thought was - let's let that router pull its WAN IP directly from the ISP, and have the RTP300 just act as a passthrough. The weird thing is that you'd think that if I click Disable Firewall and NAT, the RTP300 would be smart enough to disable its DHCP as well and just pass that request up to the ISP. It doesn't. When I also turn off the local DHCP the second router still couldn't get an IP from the ISP.

And my other question is: assuming I got all this to work, does the SIP require the RTP300 to pull an IP number from the ISP? If so, that could explain why it all isn't working.

Of course, the documentation from Linksys/Vonage of all of this is minimal to nonexistent.

Ok, let's try again, I think you're better off leaving the RPT300 alone. Can you disable the DHCP server on your wireless router? If so, you can just connect the LAN port of the wireless router to a LAN port of the RPT300 and the WGR can be your passthrough. You'll probably need an ethernet crossover cable to do that. That will still allow you to use QoS on the RPT300 and you'll only have one NAT point. What do you think?

Posts: 44 · Full Forum Member Joined: Nov 01, 2005 Posts: 44

You're right - I tried to do that, except that some damned bugs in the Netgear router firmware cause it to fail to route DHCP from the RTP traffic over the wireless. The other thing I tried was to make the Netgear the DHCP server, and plug the RTP into the LAN side of the Netgear (rather than the WAN side). The problem with that configuration is that there's no way to set the gateway on the Netgear's DHCP server. I.e. in that configuration the gateway for all the machines on the network should be the RTP, even though the WGR is the DHCP server.

Looks like I'm stuck with the double NAT.

Posts: 132 · Vonage Forum Senior Joined: Aug 16, 2005 Posts: 132

enodo,

Double NAT works (reported problems with VPN) at some (negligible?) speed cost. You might want to reserve IPs, and instead of auto getting the DNS from your ISP, enter primary and secondary DNS addresses in your router. That has helped my config tremendously.

Posts: 44 · Full Forum Member Joined: Nov 01, 2005 Posts: 44

You're right. It's mostly a matter of trying to understand...