0

We have a Windows Server 2003 server. We will install a new Windows Server 2012 R2 Essentials soon.

Right now when the server is down, clients can't go on the internet. Is there a way, for the new setup, to set this up so they still could go on the internet even if the server would go down?

We only have one server. It's a small business. We have a separate router that could act as the DHCP server.

I'm the one who'll do the installation of our new 2012 server Essentials. It will be my first install. I already manage a windows 2003 and a windows 2008 server. My server skills are pretty basic. I'm used to configure simple routers.

Edit: Did some editing to the original question (which was confusing). Sorry if the comments sometimes don't match with the question anymore.

Jim_Lafleur
  • 1
  • 5
  • 1
    The question at this point is _why_ can they not go on the internet? What happens when they try? Is it just DNS that's failing, for example, or are you actually running a proxy on the server or anything like that? – Rob Moir Jun 16 '15 at 17:05
  • The server acts as the DNS and DHCP server. Normally, are clients supposed to still be able to go on the internet when the these 2 are down with the server? – Jim_Lafleur Jun 16 '15 at 17:08
  • 4
    Start by getting a rudimentary understanding of DHCP and DNS and how they work to give clients network connectivity and name resolution. This is pretty basic stuff. I'm not trying to be harsh, but if you're managing this network you should already know this stuff. If your DNS server is down how would you expect the clients to be able to resolve external (internet) names? – joeqwerty Jun 16 '15 at 17:10
  • I know what DNS and DHCP do. And, I know they are on the Windows Server 2012 R2 Essentials. That's why I'm asking : Is there a way to set everything up (router/network/server/etc) in a way that people could still go on the internet, even when the server would be down? – Jim_Lafleur Jun 16 '15 at 17:24
  • Sure. Give the clients a secondary DNS server to use that isn't the Essentials server. You could also set up DHCP services on the router and enable that if the server is down. Note that clients would only need to use the router for DHCP if 87.5% of their DHCP lease time has expired and they're unable to communicate with the server to renew their DHCP lease, at which point they'll go into the rebinding phase and seek out any available DHCP server. Also, I'm assuming this isn't an AD domain and that you have only the one server. – joeqwerty Jun 16 '15 at 17:28
  • How do you give the clients a secondary DNS server? You set this on the DHCP server? That DHCP server could be in the router right? – Jim_Lafleur Jun 16 '15 at 18:06
  • @Jim_Lafleur Did you do the original configuration of the DHCP service on your Windows server? If not, is the person who did that configuration available to help you change it? I recommend continuing to use the Windows DHCP service over changing to setting up DHCP on the router. I find the Windows service more powerful and easier to use than any other router or firewall based services. – Todd Wilcox Jun 16 '15 at 18:12
  • I'm sorry the initial question was confusing. Edited it to me more clear. If I want the clients to be able to use a secondary (public) DNS server when the server is down, do I need to configure the DHCP in the router? Or can I simply tell the Windows Server's DHCP the secondary DNS? (Will the client be able to connect to that secondary DNS if the server is down? – Jim_Lafleur Jun 16 '15 at 18:30

2 Answers2

0

What @joeqwerty said about basic networking knowledge is important. That said, to simply answer the question, the way to give access for clients when your DHCP and DNS server is down is to provide a backup DHCP and DNS server.

However if your WS is also the router/NAT gateway you'll need to provide a backup router too, at which point you may as well just use a standalone router/gateway and selectively offload tasks to the Windows Server.

noitsbecky
  • 606
  • 3
  • 13
0

Assuming you are running a Windows domain on the 2012 R2 Essentials server, then you can't do this without adding another server. You have to host DNS exclusively on your domain and your domain joined computers have to use a Active Directory integrated DNS servers only. If the AD integrated DNS servers for your domain are all down (and it sounds like you just have one), then none of your clients can get DNS resolution and they won't be able to resolve names for servers on the Internet either.

You can provide some resilience by building another 2012 R2 server, joining it to the domain, and installing DNS on it. If the essentials license lets you do this, it would also be good to make the additional server another domain controller so you have an additional copy of your active directory.

Todd Wilcox
  • 2,831
  • 2
  • 19
  • 31
  • 1
    We only have one server. It's a small business. We have a separate router that could act as the DHCP server. We don't have the budget to install a second server/domain controller – Jim_Lafleur Jun 16 '15 at 17:48
  • 1
    Then add more DNS servers to your DHCP options. You can do a web search for public DNS servers and include those. When your local DNS server is down, your clients will go straight to the internet DNS servers. – Todd Wilcox Jun 16 '15 at 17:50
  • 1
    Like in the router I could say : First DNS server : IP of the Windows server. Second DNS server : IP of the google DNS (8.8.8.8). Would that work? – Jim_Lafleur Jun 16 '15 at 18:02
  • 1
    If the router is your DHCP server, then yes. You wrote in a comment that your 2012 server is providing DHCP, so you would instead put these two DNS servers into the DHCP options in the DHCP console on the server. – Todd Wilcox Jun 16 '15 at 18:07
  • 1
    So, beside loosing the Advanced DHCP control of WS, there's no problem using the router as the DHCP right? I mean we just have 10 users and maybe 10 devices. We don't do anything fancy with the DHCP. – Jim_Lafleur Jun 17 '15 at 18:18
  • As said before will only have one 2012 r2 server. So if I understand well I can configure the DHCP of 2012 r2 server to have DNS 1 as itself and DNS 2 as google DNS (8.8.8.8). If my 2012 r2 server goes down, it's clients will go straight to google DNS (8.8.8.8), Right? If the down time lasts 2 days, for example (worst case scenario), will the clients still keep their original IP address and be able to connect to google DNS? (Even if they restart their computers?) – Jim_Lafleur Jul 06 '15 at 22:45
  • The problem is that even when the 2012 server is up some DNS requests will go to Google also, which won't work for local domain records like resource records. Just put only your local DNS server as a DHCP option and that's it. Just one DNS server. – Todd Wilcox Jul 07 '15 at 01:32
  • OK, so I'll put 192.168.5.254 (IP of the server) as the only DNS server in : DHCP : MyServer.MyDomain.local: Scope: Scope Options: DNS Servers. Then, how is it exactly that the clients will be able to know how to go on the internet? When the server's DNS server doesn't know how to resolve a domain name then it forwards it to the gateway? – Jim_Lafleur Jul 07 '15 at 12:13
  • Your Windows DNS server will use root hints that are set in it by default, and if there are specific upstream DNS servers you would prefer it to query then you can add them as forwarders. – Todd Wilcox Jul 07 '15 at 12:15
  • OK. Would you please indicate what are the steps to add a forwarder? Is it in the DNS Management console? Let's say I'd like to have 8.8.8.8 – Jim_Lafleur Jul 07 '15 at 14:03
  • I don't recommend adding a forwarder unless you have some specific DNS services provided by your ISP that require getting next level DNS service from their server(s). 8.8.8.8 wouldn't fit that scenario. Technically how to add forwarders is a separate question but it's easy to add them by right-clicking on the server name in the DNS MMC and choosing "Properties". – Todd Wilcox Jul 07 '15 at 14:41
  • With all possible respect, Jim, I think you have a lot of research to do about Windows networks, AD, and DNS services and it can't all be done in a StackExchange question. – Todd Wilcox Jul 07 '15 at 14:42
  • 1
    Thanks for the advice Todd. Found the answer myself before I've read you answer. For the next newbie that comes here. Here's how to add a Forwarder in Windows 2012 R2 : "A forwarder is a Domain Name System (DNS) server on a network that is used to forward DNS queries for external DNS names to DNS servers outside that network. " https://technet.microsoft.com/en-us/library/cc754941.aspx – Jim_Lafleur Jul 07 '15 at 16:42
  • 1
    After you've done that here's how to check if your clents do use the public DNS of your choice (in my case google 8.8.8.8) : www.dnsleaktest.com. In my case it didn't return 8.8.8.8 but a bunch of Google servers. That ok. I now knew I was using google servers for public DNS. – Jim_Lafleur Jul 07 '15 at 16:43
  • 8.8.8.8 is basically a bunch of google servers. https://xkcd.com/1361/ – Todd Wilcox Jul 07 '15 at 17:03