Reconfigure Comcast Business IP Gateway so can use own router
I currently have a Comcast Business IP Gateway, SMC8014, connected to a switch with multiple PCs. I want to add wireless so I want to add my own wireless router (using a Netgear WPN824). Thus I need to reconfigure the Comcast Cable Modem/Router to act just as a Cable modem. I have accessed the Comcast SMC8014 and have all the current settings. Then I need to configure my router. So here are my questions:
1.) What do I need to all turn off or disable in the Comcast Modem/Router?
2.) What IP address do I need to use to configure my new router? The modem and router each have to have their own IP address correct? I'm assuming I got a Static IP from Comcast, the IP address to access the Comcast Gateway is 10.1.10.1. But what is my static IP (how do I tell)? Which page in the config area do I need to look at, eg. they list under Internet Settings: WAN DHCP IP Address, WAN Internet IP Address, Static IP Block, and under Local Settings: Gateway IP Address, IP Range Start, etc.
3.) What is a public static IP address? They talk about public static routable IP addresses vs. private static IP address.
Thanks,
Joe B.
1.) What do I need to all turn off or disable in the Comcast Modem/Router?
2.) What IP address do I need to use to configure my new router? The modem and router each have to have their own IP address correct? I'm assuming I got a Static IP from Comcast, the IP address to access the Comcast Gateway is 10.1.10.1. But what is my static IP (how do I tell)? Which page in the config area do I need to look at, eg. they list under Internet Settings: WAN DHCP IP Address, WAN Internet IP Address, Static IP Block, and under Local Settings: Gateway IP Address, IP Range Start, etc.
3.) What is a public static IP address? They talk about public static routable IP addresses vs. private static IP address.
Thanks,
Joe B.
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APC_NOC: Between the SMC and the switch, you could put your own firewall up as an option. I have done this before using the Untangle Application server (in bridged mode) to act as an IDS in between the SMC modem and network switch. You can also allow the Untangle appliance to dole out the DHCP addresses or even one of the internal servers (i.e. SBS 2003) as well if you don't want the wireless router to do so. Works like a charm.
ASKER
Thanks both of you for you help! I think I just about have it setup now. Your explanations helped. I did find out from Comcast that I don't have a Static IP - the SMC set as modem/router gets a dynamic IP from Comcast. Here's what I did and I have a follow up question please
1.) I left the SMC set up as the modem/router (DHCP enabled and all the other settings set as was)
2.) Left the Netgear router set as it came out of the box, DHCP enabled, etc.
3.) Connected patch cable from the SMC, Port 1 (a LAN port) to the "Internet" connection on the Netgear Router.
4.) Connected a patch cable from a port on my 16 port switch (where all my PCs are connected to) to Port 1 (LAN port) on the Netgear router, so all PCs are connected to it.
4.) Rebooted all PCs and they all got new IP addresses from the router and on the 3 PCs I tested I have good internet connection.
MY QUESTION:
Do I need to disable the DHCP, or anything else, in the SMC cable modem/router? Everything seems to be working as is and since the only thing connected to the SMC is the router I wouldn't think I'd have to??? But I'm not sure.
Thanks
Joe
1.) I left the SMC set up as the modem/router (DHCP enabled and all the other settings set as was)
2.) Left the Netgear router set as it came out of the box, DHCP enabled, etc.
3.) Connected patch cable from the SMC, Port 1 (a LAN port) to the "Internet" connection on the Netgear Router.
4.) Connected a patch cable from a port on my 16 port switch (where all my PCs are connected to) to Port 1 (LAN port) on the Netgear router, so all PCs are connected to it.
4.) Rebooted all PCs and they all got new IP addresses from the router and on the 3 PCs I tested I have good internet connection.
MY QUESTION:
Do I need to disable the DHCP, or anything else, in the SMC cable modem/router? Everything seems to be working as is and since the only thing connected to the SMC is the router I wouldn't think I'd have to??? But I'm not sure.
Thanks
Joe
You do not have to disable DHCP. It is fine the way you have it set up. Note that by not changing anything on the SMC will help you whenever there is a service call that goes into Comcast. They will (should) have a record of your trouble calls, and make notes of what was changed. This way, you can save time on the phone with them. So if it ain't broke, then don't try and fix it.
One additional note as to why you should leave it as is. Suppose you lose your internet connection (from behind the Netgear). You could then take a PC and connect it to the SMC, thus bypassing the Netgear. If you can browse, then you know the issue is with your Netgear. If you cannot, then you know that there's an issue with the circuit/connection or with the SMC. In this scenario, it would be on Comcast to address the issue.
Honestly, in my opinion, I wouldn't have two DHCPs running as it could cause headaches down the road. I would disable the DHCP on the SMC and give it an internal static IP address (along with the other LAN ports that it houses), then allow the Netgear router to connect to just that one static IP address (i.e. it's gateway) and dole out DHCP IPs for the switch that is connected to it.
The only other thing I would note is that if you plan on running some sort of 'server' from behind the Netgear, you really won't be able to as the SMC nor the NetGear don't have a setting for 1-to-1 NAT routing. The work around would be to just hook up the 'server' to one of the extra LAN ports on the SMC, give it a static IP address and use port forwarding from the SMC to the server for whatever your needs are.
The only other thing I would note is that if you plan on running some sort of 'server' from behind the Netgear, you really won't be able to as the SMC nor the NetGear don't have a setting for 1-to-1 NAT routing. The work around would be to just hook up the 'server' to one of the extra LAN ports on the SMC, give it a static IP address and use port forwarding from the SMC to the server for whatever your needs are.
ASKER
Thanks both of you. You both helped a lot so it was hard deciding on which answer to pick entriely. I think API NOC did a better job in my case helping me with the more direct solution, but mwecomputers also helped in my learning more about all this stuff. Thanks again.
Comcast just installed a business class line for me with 5 static IP's and a SMC8014 modem. I wound up finding this thread as I also was wondering how to get to my static IP's given the router was doing NAT. On a whim I just tried assigning my computer one of the static IP's (along with the specified gateway, etc) and it worked!
So, it looks like at least the current versions of the router are set up to provide a NATed address if you use DHCP as well as routing the static IP's if you assign them manually.
So, it looks like at least the current versions of the router are set up to provide a NATed address if you use DHCP as well as routing the static IP's if you assign them manually.
With that kind of configuration, why have a "firewall" at all? My recommendation is more sound to address this request.