Confused and frustrated over network setup

[incharge1976]

Notice this is in the wrong forum, sorry!

Thank you before hand for taking the time to read this and respond. I may sound a little silly by saying things you probably know, but I want to make sure I get everything out right.

Here is my current setup:

1 smc gateway through comcast
1 linksys wireless router
5 static ip addresses (I probably only plan on using three, but that is neither here nor there)
1 computer running 2 operating systems that connect wirelessly (Windows 7 is the main OS and the Ubuntu 12.04 Server in Linux is accessed through VirtualBox)
3 additional computers that connect wirelessly

My original setup was to have the gateway connected directly into port 3 of the router. The gateway address was 10.1.10.1. The gateway would give out an address ranging from 10.1.10.102/200 to the computers on the network so they could access the internet through comcast's public ip of 50.xxx.xxx.30. I then set up a 1:1 NAT on the gateway to tell it to take the private ip of 10.1.10.115 (linux server) and point it to my static ip address of 50.xxx.xxx.25. The result was to give my windows 7 and the other computers an ip address of 50.xxx.xxx.30 (comcast's) and my linux server 50.xxx.xxx.25 when checking it on the internet.

Everything seemed to be working well. I then ran into a huge problem with the server when trying to enter in my static ip address 50.xxx.xxx.25, comcast's mask 255.255.255.248, and the gateway of 50.xxx.xxx.30. The server is able to access other sites, ping other sites, and ping comcast's ip of 50.xxx.xxx.30 only when I was using 10.1.10.115 as the ip, 255.255.255.0 as the mask, and 10.1.10.1 as the gateway. As soon as I moved it to my static ip address 50.xxx.xxx.25, comcast's mask 255.255.255.248, and the gateway of 50.xxx.xxx.30 it stopped working completely.

I decided to reset the router and Comcast reset the gateway for me as I obviously had it configured wrong. So now I'm back to square one.

I would like to know how to set up the router and gateway to allow my server to be able to access the internet and the internet access it. I'd appreciate if you could give my a somewhat detailed response as I can't find anything on the internet and Comcast not helping much either. Thanks again!!

[Philip]

Your "gateway" has two IPs, an external public one (50.x.x.30) and a private/internal one at 10.1.10.1 (not routable to the internet, this is for local intranets). All IPs assigned by it via DHCP in the 10.1.10.x range are private as well. You can not use its external public IP as a gateway unless it is reconfigured from NAT routing to bridge mode (not sure if it is worth the effort or allowable by your ISP).

As far as the wireless router, the easiest thing would be to use it only as an access point (by ignoring its WAN/Internet port), there are detailed instructions here: http://www.speedguide.net/articles/h...ess-point-2556

Whatever you do, remember it is easiest to have only one device that has NAT routing and DHCP server enabled.

I hope this gives you some pointers..

[YeOldeStonecat]

What services do you need available from the internet.....on this Linux server?

[incharge1976]

What services do you need available from the internet.....on this Linux server?

Strictly email....We have been sending out about 40,000 emails a day for various investment banks and colleges for the last 6 years. The emails go out to physicians and investment bankers. We were using an outside service but the customer service wasn't the best. We decided to move it in-house. I don't have an issue with programming in linux and have the box almost set up. All I need to do is get the networking right so the box with the static ip, mask, dns, broadcast, and network ip addresses can communicate with the rest of the network as well as reach the internet to be able to sent the mail as well as receive mail. I have an issue with networking as I have never set one up.


Thanks for the help...

[YeOldeStonecat]

If you do a search in the forums for Comcast SMC..you'll see a few posts of mine going into detail on how to setup your own router behind the Comcast provided SMC gateway...using the static public IP address on your own routers WAN interface. The SMC has a checkbox to disable firewall for true IP static subnet. I'm typing from behind one right now...on a Comcast 50 meg pipe and a linux based firewall with several public IPs..but I gotta pack up and head out of here to the next onsite.

Do port forwarding if necessary on your own router, although sending outbound e-mail doesn't require port 25...that's only needed for inbound.

FYI..sending out 25k mails per day....you're going to have to do a LOT of legwork to keep yourself off of blacklists and bad reputation lists.....that spam filters use to block spammers. It really is easier to use services like Constant Contact or other mail marketing services.