Please help with configuration of a server

The Comcast router needs to forward that public IP address to a priavte Static IP address through static routes within the comast router settings.

Make sure the server is serving DHCP and not the router. This will cause you no end of grief if the DHCP is served by the router.
Make sure your internal IP range is 192.168.6.0/24 and higher. That is: 192.168.7.0/24 ... .8.0/24+ so as to not cause problems with VPN connections from home based users.

Put a switch in between the SMC and the second NIC of the server. Plug both the WAN port of the router and the second NIC into that switch. Plug your Comcast modem into the switch to enable both to grab an IP from Comcast.

Then you will be able to properly bind the external IP address to the server's second NIC.

Philip

u guys miss understood the question or maybe i didnt say it right.

if the smc gateway from comcast has a public ip of 75.xxx.xxx.48 subnet mask 255.255.255.0 and i have a range of ip's from 75.xxx.xxx.47-43. Now i want the server to have 75.xxx.xxx.43. How do i set up the Nic so i have that ip as a public ip for server.

as i said i set up a nic with ip 75.xxx.xxx.43 subnet mask 255.255.255.248 and gatway ip 75.xxx.xxx.48.
But it doesn't work.

The NIC of the server? You would need to keep the server as a private ip address then forward the public IP address to the private ip address.

yeah but if i do that i will have a 75.xxx.xxx.48 as public ip. I want to have 75.xxx.xxx.43 as public ip.

Dexter,

Using the above configuration as I indicated with the switch, you would then bring up the properties for the second NIC and input the IP address, subnet, gateway, point the DNS settings BACK to the SBS server and disable File and Printer Sharing along with the first line item on the NIC (Windows Networking I think).

Both the server and the router would then sit separately and pull their Internet IP from Comcast.

Philip

ok ,  if i have 2 NIC's on the server , both of them i need to connect to gateway ? if so , witch one i configure with 75.xxx.xxx.43 as public ip. So when i setup again the server witch nic i will assign to the public ip. thanks

Dexter ...

For clarification I attached a drawing as words cannot express ...

Philip
08-07-21-NW-Diag-SBS-Switch-Rout.png

Note ... that I forgot to put the line between the switch and the ComCast modem! :P
Philip

and what ip will this pull ?

ok this is the config i have , and this config pulls the gateway ip 75.xxx.xxx.48
but i want to assign 75.xxx.xxx.43 to the sbs 2003 server and leave the 75.xxx.xxx.48 for a separate Lan witch i will add later on.
setup.PNG

We are on the same page! ;)
Philip

ok i still need some clarification ... that Comcast gateway that i draw is a Modem type Gateway that has a built in Dhcp.

So if i leave the tcp/ip options of the nic's as default , NIC 1 that's connected to the SMC gateway pulls a ip of the dhcp range. which is 10.1.10.58

IC.
So, the SMC is a combo unit that has the DSL modem AND gateway router installed?

Presents a bit of a pickle ... but not too major. Can you ask Comcast to send you an ADSL stand-alone modem? Then the above configuration will work. If not, then does the SMC have the ability to bind the extra IPs given you by Comcast? If not, that is a bit silly since they are giving you the IPs with your service!

In any event, a stand-alone modem is the best route to get to the above.

Otherwise, you will need to plug in NIC 2 from the server to the SMC making sure the DHCP IP range on the SMC for NIC 2 is DIFFERENT than the internal IP range for your SBS clients. Then you port forward SMTP 25, RWW 4125, HTTP(S) 80 & 443, and VPN (1723?) to the IP of SBS NIC 2 which will still be set statically.

Philip

The basic RRAS firewall will not allow any of the clients connected to the SMC to connect to internal resources without them first using the Remote Web Workplace or VPN for authentication. Works ... but not a perfect scenario.
Philip

here are some screenshots from the Comcast's SMC Gateway
1.PNG
2.PNG
3.PNG
4.PNG

and i talked to with Comcast's Techincal service and they said it should work perfect , but i need so set up the server corectly with a subnet address. I tried all the subnets possible but the server has no connection.
If i leave the NIC 1 with default settings , it will pick up an ip from the SMC's Dhcp and works but will have a public ip of 75.xxx.xxx.48.

I tried to set up Nic 1 with a ip of 75.xxx.xxx.43 , subnet mask of 255.255.255.248 and gatway ip of 75.xxx.xxx.48 , but has no connection . It doesnt work.

The reason it doesn't work is because you are behind the router which doesn't route public to public. The Comast router can only route one internal IP address range at a time. You are using the private 10.1.10.0 as your internal IP address range. Trust me I have the same setup as you do at one of my locations. The internal NIC doesn't recognize the public 75.xxx.xxx.48 IP address because the internal NIC\default gateway for the internal network is 10.1.10.1 which isn't on the same network address\subnet as 75.xxx.xxx.48.

and what should i do ? call comcast to disable that dhcp option on the smc ? and then i can use that smc as a modem , and have my ip's assigned manually ?

If you can do that you are good to go ... the Comcast stuff is beyond me as our ISPs up here with the exception of one use a dedicated ADSL modem ... and we don't use that one.
Philip

What the issue is that the SMC is a router. With a Cable Modem you don't have two network cards one internal and one external.

Static Routing Setup
Users can manually add static routes to routers connected to the gateway LAN to create specific
paths to a destination.
Setting a static route allows devices routed by the Comcast commercial gateway to communicate
with the separate subnet of a router connected to the commercial gateway.
For example, a stand-alone router (IP subnet address 10.1.10.33) is connected to the Comcast
commercial gateway (IP address 10.1.10.1). The stand-alone router is configured with a static
route rule to route the subnet 111.222.33.0, subnet mask 255.255.255.0. By adding a static
route called My Router and configuring the destination IP to 111.222.33.0, the subnet mask to
255.255.255.0 and the gateway IP to 10.1.10.33, all PCs on the router subnet 111.222.33.0
will be able to communicate with the PCs on Comcast commercial gateways subnet 10.1.10.0.
A maximum of eight static routes may be added. To set up a static route rule, you must first know
the destination IP address, the subnet mask of the destination IP address, and your LAN IP
assigned to the router by the Comcast commercial gateway.
To create a static routing rule:
1. Enter a Name for the router that will make the route easier to remember (has no effect on
the static routing function).
2. Enter the Destination IP.
3. Enter the Subnet Mask of the destination IP.
4. Enter your local LAN Gateway IP address (The LAN IP assigned to the router connected
to the Comcast commercial gateway).
9
5. Click add. The new static route will be added to the static routing table.
6. Repeat steps 1 through 5 to add additional static routes.
7. Click apply to activate the static routes.
An example of setting a static route rule is shown in Appendix A.
To remove a static routing setting:
Click the Remove link on the static routing table to remove the route. The entire route
is removed.

yes i know that , but all that setup its having a public ip address of 75.xxx.xxx.48 . i have 5 avilable static ip's. If i want to assign a public one of 75.xxx.xxx.43 thru that SMC to one of my servers how do i add it ?
because when i ping 75.xxx.xxx.48 , i get a ping because thats the public address of the smc gateway, but if i ping 75.xxx.xxx.43 doesnt go anywhere ...

What Comcast SMC Gateway model number do you have?

I have configured many of their all-in-ones and each one usually has very screwed up BIOS settings applied in them, especially when it comes to port forwarding and IP address utilization.

When you are in the setup it asks for the Gateway IP address which is one of the other public IP addresses. There is another way to do this by going to the firewall settings and setting the 1 to 1 NAT.

yeah i tried to go into that with the Gateway ip address but doesnt work

Can you please do a screenshot of the config you are doing?

the model # is SMC 8014

Here is a link to a copy of the Comcast Business IP Gateway User Guide:
http://www.mwecomputers.com/EE/Comcast_Business_IP_Gateway_User_Guide.pdf

Finally got it working, called Comcast to disable the DHCP future , and i was able to pull the static ip's for all my devices.

Thanks for that! :)
Philip