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Updating/changing DNS on Server 2008 R2

We recently received our updated ip, dns settings from our service provider to update on our server etc. I have a few questions however.

- Can I just change this on the adapter settings, and then the advanced/dns tab to add in new settings? Or do I have to fully reconfigure DNS on the server?

Things are setup like this currently:

Cable Modem > Router > Switches.

Router is 192.168.0.1
Server is 192.168.0.2 and handles DHCP for the office building etc.
Server subnet: 255.255.255.0
Server DNS: 24.223.0.16 and 192.168.0.2 and under advanced dns tab also 24.223.0.2

The new information that has been given to me is a static ip. But not sure if that is based on our ISP box but I assume it is. And then a different gateway, and two different dns.

So I suppose it all goes back to my questions of, can these changes just be made on the adapter or do I need to do more work and include any of it on the router? (currently router is just basically default settings so I don't think I need do anything there as I haven't in the past)

Thanks!
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ZephyrM
Asked:
ZephyrM
1 Solution
 
Axis52401Security AnalystCommented:
Because the cable modem plugs into the router (which it should) you'll actually want to make sure you router is configured with the new DNS information, not the server. Also, you don't actually need to enter an external dns entry on your server because that's what the default gateway (router) is for. Anything that the server can't locate in its dns table (which is anything on the internet) it will ask the default gateway to find. So you can freely update the dns settings on your server but it's not actually necessary. The router is what needs updated and most likely the WAN interface on the router is set to DHCP so it will get the correct information by default. 192.168.0.1 is just how you access it internally. So really you shouldn't have to do anything.
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Garry MastersCommented:
wow,  not sure I have enough info here but my thoughts are somewhat the opposite of what you seem to be expecting to do.

It seems like your ISP is changing you from a dynamic wan to a static wan  (usually a good thing).  If true and they own the cable modem  and you own the router then they will do what they need to with the modem and you need to change the router's WAN config from dynamic to static and put the ip address(es) that they gave you in the WAN interface config page of the routers WAN settings  (at the time of the cuttover).  Usually they will also give you a subnet mask for here too. If the assumptions above are correct, you have no internal network DNS or DHCP changes needed, only Router WAN/DNS changes.  (if assumptions are not correct then this answer is wrong and more info is needed, or maybe someone else interpreted this better (you said all they gave you was new static IP address's).  By the way-  if THEY own both the modem and the router,  then usually THEY will change all these IP changes for you and you have nothing to do except know what the info is in case you need it for remote access or other things.  Basically,  your DHCP tells the PC's where INTERNALLY to go for DNS (often in a small network like at home  the router also does the DNS/DHCP).  If that DNS is a Server then the server can provide 'unique-to-you' DNS resolutions  (like Cname or A-list records you want internally addressed like if you have a web server you host internally via NAT your unique DNS might say go to its internal address rather than a public one)  and anything not called out on that server will then check the external DNS you are putting in the router. (when the router was dynamic it got this info automatically,  as a static one it needs to be entered by you or the ISP)

The info you provide on the adaptor settings also seems to be wrong per my understanding of best practices- DNS addreses here should be internal DNS not external- (so you resolve locally before externally),  then if no match the router or a 'forwarder'  setting tells traffic bound for the internet where to go for the big dns guys external to your intranet.  (so those public DNS settings don't normally go on the adapter,  they go in the router and/or in forwarder settings.)  Sorry if this confuses anything- may be best to get a local tech support or even your ISP to help.
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DrDave242Commented:
If you have an Active Directory domain in place, everything in the domain should be using only internal DNS servers. If your only internal DNS server is 192.168.0.2, that should be the only DNS server listed on all of your domain-joined machines (including 192.168.0.2 itself).

For external (Internet) name resolution, you can configure forwarders on the DNS server (right-click the server's name in the DNS console and select Properties, then click the Forwarders tab), which will typically be your ISP's DNS servers, or you can leave the forwarders list blank and use root hints.

In any case, the IP addresses given to you won't affect your internal IP scheme at all. If you need to make any changes at all, they'll be on your router. You should check with your ISP to determine whether you need to set the static IP on your router's WAN interface or leave it as DHCP. Many ISPs use DHCP reservations to assign static IP addresses, as it makes administration a little easier on their end.
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ZephyrMAuthor Commented:
Thanks I will check with the ISP on that. The reason for the whole upgrading is because we are moving away from a Cable Modem setup and into a fiber/T setup so a whole new box I have to plug the router into. They said update the settings on the server with new dns etc so that is why I figured I'd have to do it there and not on the actual router.
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ZephyrMAuthor Commented:
And yes, we are using Active Directory on the 2008 R2 server. I wasn't using any forwarders etc however.
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footechCommented:
DrDave242's advice is correct.  None of the NIC settings should reference external (like your ISP's) DNS servers.  So if you're saying that you currently have the DNS setting for the NIC on the server set to use 24.223.0.16, 192.168.0.2, and  24.223.0.2, you should remove the 24.223.0.16 and 24.223.0.2, and then configure the forwarders in the DNS server to use those IPs.
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ZephyrMAuthor Commented:
Great, I'll work on that this weekend when no one is in the office so connectivity won't be an issue during the day. Since the gateway and ip have changed as well, should I update them on the router however? I have nothing from ISP on the router with our current setup but then again we are moving from Cable to Fiber. (Pry the question that needs to be asked with the ISP I suppose.
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DrDave242Commented:
Since the gateway and ip have changed as well, should I update them on the router however?
Most likely yes, although you should check with the ISP to be sure.
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