Switch DHCP server from the router to the Windows Server 2008

We have been using our SonicWALL router as the DHCP server. I have been thinking to use our Windows Server 2008 as the DHCP server instead. The major reason is that the IP Address Lease Table in SonicWALL only lists the IP address and its corresponding computer's MAC address, not the computer's name. Recently, we had a two day power outage. Once the power was back, we noticed that many computer's IP addresses were changed. So this becomes another big reason we would like to make the switch.

1. Do you use your router or your Windows Server as the DHCP server?
2. If I do the switch, is there anything I should be aware of?

Y YconsultantAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Nick RhodeIT DirectorCommented:
Pretty simple actually.  I would setup and install DHCP service on the server and configure it 1st before switching over.  Make sure your DNS settings are correct on setup then turn the DHCP off on the sonicwall and turn it on, on the server.

Computers might act a little funny but a simple reboot should fix that or open command line and do a ipconfig /release and then ipconfig /renew.
Y YconsultantAuthor Commented:
You said that "Make sure your DNS settings are correct..."
- Please kindly advise what DNS settings should be taken care of.
Mal OsborneAlpha GeekCommented:
All sounds pretty simple.

DHCP leases have a time associated with them. On Windows, it defaults to 8 days. Machines renew their lease when it is half expired.  The lease time is a compromise. Set to a high value, like 6 months, IP changes would be rare, however a lot of IPs would be wasted and not reassigned. If a laptop is connected to the LAN for 5 mins, it will be given a lease, and that IP remains unusable until the lease ends.

Usually, changing IPs happens  more when the DHCP scope is close to full. Best to ensure you have a heap of extra IPs and set a long lease time if you don't want IP changes.
Cloud as a Security Delivery Platform for MSSPs

Every Managed Security Service Provider (MSSP) needs a platform to deliver effective and efficient security-as-a-service to their customers. Scale, elasticity and profitability are a few of the many features that a Cloud platform offers. View our on-demand webinar to learn more!

yo_beeDirector of Information TechnologyCommented:
How many devices on your network? If it is a small environment you can try what I am recommending. No reboots or ipconfig commands

What you can do is setup a scope that is outside the range that is currently given. Setup your new DHCP server with a range of ip-addresses outside the current scope of max issued ip-address.
Say your sonic wall issues to 192.168.254, but only to is being used. Change your sonic wall max range to what has been issued. The set your new DHCP to start at max of sonic wall +1 more. 192.168.151 to Once configured the shut down your DHCP service on the sonic wall. This will have no interruption to your network
Y YconsultantAuthor Commented:
So I assume there will be nothing to do with DNS server, correct?
yo_beeDirector of Information TechnologyCommented:
You need to set DNS options, gateway in your need server. It has been awhile, but I think the wizard during setting ask these questions.

Here is a video:
If you were happy with your router's DHCP service so far, but for the problem you mentioned, it will be pretty easy:

- Install DHCP Service on your Win2008 server
- If you have an AD domain, your Win2008 server must be authorized in the AD domain. As such it must be a domain member or domain controller.  If you do not have an AD domain (which I suppose is your case), your Win2008 server is a standalone server and nothing particular needs to be done AFAIR. Check https://technet.microsoft.com/fr-fr/library/dd296633%28v=ws.10%29.aspx .
- Configure your DHCP scope so that it does NOT overlap with the current scope of your router (you will be able to extend that later on). The subnet mask is very likely to be
- Set the DNS to be what they were in your router's DHCP config (if you need a second DNS and don't know what to use, use one of your ISP or google's
- Set the router (default gateway) of in DHCP's options to be the IP address of your router
- Set any other option that was set in your router's network and, potentially, other usefull options if you need some
- Start the DHCP service. You can use the services applet to start it manually. It can take a little time. Make sure it starts. Even if it not authorized, it should start as long as there is no authorized DHCP server in your physical subnet.
- When it has started OK, turn off the dhcp service in your router
- Start one client and check that it gets IP addresses OK
- You may now extend your dhcp scope if you want

Some step-by-step details :

Install DHCP and create a scope for the network

    On your server, using Server Manager, select Roles, and the select Add Roles.
    On the Before You Begin page, select the Skip this page by default checkbox, and click Next.
    In the Select Server Roles list, select DHCP Server and click Next.
    On the DCHP Server page, click Next.
    On the Select Network Connection Bindings page, accept the default settings and click Next.
    On the Specify IPv4 DNS Server Settings page, in the parent domain: textbox, type in whatever DNS Suffix you want to use, I used mynet.home, and then click Next.
    On the Specify IPv4 WINS Server Settings page, accept the default settings and click Next.
    On the Add or Edit DHCP Scopes page, click Add. Use the following settings.

    Scope Name: (or whatever your scope is)
    Starting IP address: (or whatever your scope is, not overlapping the current dhcp scope)
    Ending IP address: (or whatever your scope is, not overlapping the current dhcp scope)
    Subnet Type: Wired (lease duration will be 8 days). You may change that to 1 day or whatever you want
    Activate this scope: Selected
    Subnet Mask:
    Default Gateway (optional): (your Router IP address on your subnet)
    Click OK, and then click Next.
    On the Configure DHCPv6 Stateless Mode page, accept the default settings and click Next.
    On the Specify IPv6 DNS Server Settings page, in the parent domain: textbox, type in whatever DNS Suffix you want to use, I used mynet.home, and click Next.
    On the Confirm Installation Selections page, click Install.
    On the Installation Results page, click Close.

For more details, check

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Blue Street TechLast KnightCommented:
Hi TechCity,

I don't see the point or reason for needing/wanting to switch DHCP Servers or at least not a technical one.

A) if the IP addresses just disappeared due to corruption a backup of the settings would rectify this in less than 30 seconds in either case Windows or SonicWALL.

B) if this was due to a power anomaly you need to protect all devices from power anomalies especially servers and NCPI (Network-Critical Physical Infrastructure) - in this case you're lucky the SonicWALL was not fried. At the very least it should have an APC or computer-rated surge arrester if not a small battery backups like an APC BackUPS 350 or 500. All of them are cheap insurance... less than $21 per year (they last on ave. 3 years).
Generally, if you have more than 30 users I'd recommend Windows to manage DHCP because it works so well with DNS and AD DS. In environments 30 or below you can go either way SonicWALL or Windows. In practice I also go with Windows but I actually prefer SonicWALL's concepts of dynamics, statics, the role of the scope and the ability to annotate everything over Windows but that is just preference.
Blue Street TechLast KnightCommented:

Any update on this? Please let us know so we can help!
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.