Server 2008 dns help

By rlynch@lockhartcadillac. ·
Im looking for a little dns help. I have done a lot of research, but didn???t really find what I was looking for specifically. I have a basic network of 30 clients sitting on a T1 behind a sonicwall nsa. I also have a windows server 2008 domain controller with two nics that also serves as the dns server. DHCP is coming from the sonicwall nsa. There are only basic switches that run no vlans or anything like that. My question??? When you setup the windows 2008 domain controller to serve as the dns server, do both nics(or both of the nics ip addresses) need to be put in the client dns settings? For example, one nic with private ip other nic 92.49. On the client settings, do I need to input both of those address in the dn1 and dns2? Also, on the sonicwall nsa???. On the dhcp setup I have those two ip???s from above setup to go out to clients that receive dhcp. However there is also a dns setting on the sonicwall nsa for itself. Should I be using my ips dns address or the two ip addresses from my local dns server above? I appreciated any help, thanks in advance.

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All Answers

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actually, disable one of the NICs

by CG IT In reply to Server 2008 dns help

Since DHCP is not handled by the server and you don't want to route all traffic through the server, disable one of th network cards. just ensure that the first DNS entry on workstations is the W2008 server and your ISP DNS servers are listed 2nd and 3rd by the options for DHCP. That way, queries will first go to it and if not resolved, will go to root hints. If your server goes offline for any reason users can still get to the internet.

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Request for Clarification

Thanks for the quick response. From what ive read its best practice to have the server the dhcp source anyway. If I configure the server for dhcp as well, would I want both nics still up and running? Also a question on the side of that, would disabling one of the nics decrease the speed of any of the jobs the domain controller does? Didnt know if taking one of the nics down from 2 to 1 would slow any of the work down. Thanks again.

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no need for 2 NICs unless you want to route all traffic through the server

by CG IT In reply to Server 2008 dns help

If you are going to use the server to route traffic [not really recommened, it's a server not a router], then you need two NICs. one WAN and one LAN.

side note: Network cards don't speed up any services the server provides.

Suggest a course on networking, routing and switching...

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If the 2k8 server is your DNS server

by seanferd In reply to Server 2008 dns help

then the clients should have the LAN address assigned to the DNS server.

If the Sonicwall is effectively the public DNS server, put the LAN address of the Sonicwall in the 2k8 forwarders. If you expect 2k8 server to directy serve public DNS, put the public resolver addresses (your ISP's or another service's) in the 2k8 forwarders.

The number of NICs isn't really a factor in speed on this server either way.

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NICs = Cooks in the kitchen

by nwallette In reply to Server 2008 dns help

Having two interfaces on the same subnet will only cause you trouble. There isn't any good reason to do this, and it will confuse the routing tables on the server. If you were hoping to get 2Gbps speed by doubling the physical connectivity, you need to look into NIC teaming, EtherChannel, etc. You don't get automatic redundancy and speed boosts by just plugging in two cables, I'm afraid. :-)

As far as DNS and DHCP, there are advantages to using, and not using, the server.

Using your network gear (the SonicWall in your case) is good because, statistically your server is more likely to be down than your router. (Do you regularly reboot your router for updates? How many applications do you run on your router? And well.. it's Windows.)

Using the server, management is maybe a little easier. You can save your leases across reboots and power outages, DHCP integrates with DNS so your hosts can register their hostnames with DNS upon leasing an IP from DHCP, etc..

At the size of your shop, I would just pick whichever one you're most comfortable configuring. You only need to worry about optimization if the services will be heavily loaded, and at 30 clients, they won't be.

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What about teaming?

by CIO at Alphabetas In reply to Server 2008 dns help

I think he may want to use both NICs if he wants to use teaming of the adapters- different subject though...

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I'm surprised the whole "2 NICs are better" than one keeps coming up

by CG IT In reply to Server 2008 dns help

even with 2, seperate, DSL services, not going to see an appreciable increase in Internet "speed" of uploading and downloading from the Internet.

Even dual WAN routers will ask how much to spread across each one, with the maximum of 50% of traffic on one, 50% of traffic on another...and if both are 768k up, you'll get 768k up. if both are 7mbps down, you get 7 mbps down not 14.

the only way to get 14 mbps down is to buy a service that's 14 mbps down.

So 2 NICs are not better than one. 2 NICs end up being a pain because one isn't sure which one is the problem.

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Reponse To Answer

i probably didnt explain that part of my question very well, i certainly never thought dual nics would increase internet speed. Just wasnt sure if dual nics has any impact on the domain controller jobs. such as sending install files to clients when gpo calls for it, or any local traffic for that matter. i disabled the 2nd nic and good to go. thanks again for the quick response.

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No dual NICs don't help lan traffic

by CG IT In reply to Server 2008 dns help

it can actually cause problems for lan traffic. While it's probably not going to cause loops, it will create a configuration that workstations might experience loss of contact with the server because there are 2 physical paths to the same place with 2 different addresses and unless you change it, both network cards have the same metric of 1. Thus confusion of which physical path to use. If you change the metric on one of the interfaces that is less than the other, then it will not be used until the first is not available.

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