Cable Modem - Router - Server

I have a cable modem for my internet connection. The IP address is assigned Dynamically (it hardly ever changes but it does on occassion and it IS dynamic - the ISP is running a DHCP server). I am setting up a network at home with 2 workstations and 1 server running MS Small Business Server (SBS). SBS uses a DHCP server as well, BUT (here is the gotcha) it has a rogue detection that will shut down the SBS DHCP server if another DHCP server is detected on the network. For internet sharing (SBS comes with Proxy Server) it is expecting a Static IP address. What I am wondering is will a router like the Linksys BEFSR11 1-Port Etherfast Cable/DSL Router be able to resolve my ISP IP address to a static one for my own network? This is the way I see things set up:

ISP DHCP server - Router acting as a DHCP client to obtain IP address from ISP and pass a static IP address to - local server

My only other option (that I can see) is to disable my DHCP server locally and try to get my second NIC to obtain the IP address dynamically from my ISP. This option will reduce some of the features available to me via the SBS package.

Thanks in advance!
9 answers Last reply
More about cable modem router server
  1. I use a D-link router. It has one global ethernet port that hooks up with the cable modem. It has one local ethernet port that hooks up to my hub. The ISP is a DHCP server. The router gets IP addresses dynamically from the ISP and an internal address assigned by me. The router does DHCP to my LAN or I can set the IP addresses statically to my PC's. I do not use any modem sharing software and do not do any proxy server. I simply point the NIC's to a default gateway (the router internal IP address) and give the NIC's a preferred DNS suffix in the TCP/IP properties (provided by the ISP). The LAN is seperated from the Internet by the router. I also use firewall software. In IE 5.01 I tell the browser to get the connection over the LAN and to automatically detect settings. 24/7 reliability.
  2. I forgot to mention, yes you can use 2 NIC's as well. One NIC goes to the ISP and the second NIC goes to your LAN. Use the IP address of the NIC to the ISP for your default gateway setting of your LAN NIC(s) and give the LAN NIC(s) a DNS suffix provided by the ISP. Then install your firewall software. Setup your server to DHCP your LAN or just assign the addresses statically; just 2 other pc's. This method works well and is cheaper than the router. But like I said in the previous post, I use a D-link router. I did this because I did not want to use my extra system for a gateway or server. I use it for a test lab system. Also, the router uses less power, cheaper to run.
  3. I just purchased and installed a linksys 4 port router/switch. I will work as you want. It will resolve the DHCP address from the ISP on the WAN side and has a static IP address on the LAN side. It also has a DHCP server built in so you could use that as well. I absolutly love this unit so far. I haven't found anything that it does not work with. I have a local net setup with 2 W98 pc's and a linix machine. I think it will do the trick for you. Also there is a $30 rebate going on until th emiddle of march. This thing is a bargain for $100!!

    Good luck,

  4. Check into the SMC cablemodem router. $99 gets you four 10/100 switched ports and a parallel port print sever.

    The print server is the catch for me, I absolutely HATE being the sucker with the printer on his desktop... bogs me down spooling everyone's jobs.
  5. I just saw that lists a $20 rebate on the SMC... looking better and better...
  6. Just having read your post, and only very briefly skimming over the responses an error in your logic comes to mind. Regardless of all your respondents talking about buying a hardware based router solution, i don't see this as necessary. SBS has rogue detection. Fine. Realize however that the DHCP server you are planning on using would be a DHCP server for your INTERNAL PRIVATE network, not your cable ISPs network. Your DHCP server would only assign IPs to your private subnet. Therefore, your Internet side NIC would have its MAC associated with an IP given to it by your cable ISPs DHCP server. Your private subnet NIC you would assign a static IP to yourself, and then create a range of IPs to allow your DHCP server to assign to computers requesting an IP on your network. Bottom line is that you certainly don't need to blow a couple hundred bucks on a hardware router. THere is really no problem to your proposed setup.
  7. Carteach mentions the same thing in his second post. Sorry for not having read it in full ahead of time :) That being said, he suggests a D-Link router for specific reasons, which do not really apply to you since you are planning to have a computer setup as a server.
  8. Thanks for all the advice. I did end up picking up the router since my initial problem is that I needed a static ip address to setup my server and my ISP only supplied dynamic ones. Instead of paying the big monthly fees for a static IP address I used the router to resolve the dynamic IP address to a static IP address that I can use in my internal network. It is also some added security that never hurts (and reduces the chance of my ISP finding out that I am running a server!!).

    Thanks again.
  9. With a multihomed computer your internal network NIC would have a static IP anyway. That's really a moot point now though.
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