Out of available IP addresses on one DHCP server, will other DHCP servers field the request?

I have three WinServer 2012 R2 domain controllers that also act as DNS and DHCP servers.
I have a guest wireless network that has its own subnect, 10.121.176.0/20
We have our DHCP scopes split this way across the three domain controllers with a DHCP lease time of 1 day
Domain controller 1, 10.121.176.11 - 10.121.181.255 for a total of 1,525 addresses
Domain controller 2, 10.121.182.0 - 10.121.186.255 for a total of 1,280 addresses
Domain controller 3, 10.121.187.0 - 10.121.191.254 for a total of 1,279 addresses
This gives us a total of 4,084 addresses to hand out on our guest wireless network which is plenty. I just looked at each servers stats and this is what I see
Domain controller 1 - 717 addresses in use, 808 available
Domain controller 2 - 900 addresses in use, 380 available
Domain controller 3 - 1280 address in use, 0 available
On domain controller 3 I am seeing lots of DHCP events
Event ID 1063 - There are no IP addresses available for lease in the scope or superscope "GuestWireless-176
Event ID 20287 - DHCP client request from 28E14CE87EFB was dropped since the applicable IP address ranges in scope/superscope GuestWireless-176 are out of available IP addresses
Two questions:
Once Domain Controller 3 rejects the DHCP request since it is out of addresses, will this request be fulfilled by one of my other two domain controllers?
Is there any way to even out the leases on these DHCP servers? Not sure the mechanism behind a client choosing one DHCP server over another

1 yes, the dhcp server who's scope is full will not do a dhcp
'offer'
2 dhcp that answers fastest with a 'offer' will win. A delay is configurable (but changes nothing
about the root scenario were the fastest will win)
Note that if the scopes overlap on the servers, they might not lease out all the addresses in the scope.
I would enlarge the scope as you will want to fence against unavailability of one of the servers (or a network connection for that matter). you currently have more addresses leased out than any set of two of your servers can offer.
MCP/MCSA/MCTS/MCITP

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Windows DHCP Server and Linux DHCP Relay Agent

We are trying to organize a VLAN (say VLAN 1) for guests who must be assigned IP addresses from a DHCP server in a different VLAN (VLAN 2). This DHCP server is configured with two scopes - 172.16.0.0/24 (for VLAN 2) and 172.16.4.0/24 (for the Guests
VLAN 1). The DHCP server successfully distributes addresses to clients in its VLAN (it has the IP address 172.16.0.2). For the clients in the other VLAN a DHCP Relay Agent has been setup on the router. It is DHCRELAY running on Linux (CentOS) which has
been configured to accept the DHCPDISCOVER broadcasts coming on the VLAN1 interface of the router and forward these to the DHCP server. The IP address of the VLAN1 interface of the router is 172.16.4.254 and on the VLAN2 interface - 172.16.0.254
The problem is that the DHCP server won't respond with a DHCPOFFER message to the relay agent. I have traced the frames on the router and on the DHCP server. They arrive on the DHCP server with the correct GIADDR of the relay agent. According to all documentation,
if a scope has been configured on the DHCP server and it receives a unicast message with the GIADDR set by a relay agent that matches one of the configured scopes, the DHCP server must send a unicast DHCPOFFER to the relay agent. But it doesn't.
Here is what Wireshark reports (ignore the Destination port unreachable messages, the DHCP service was stopped at the time Wireshark was running)
When the service is running, there are just DHCPDISCOVERs - no OFFER. You can see that the server has the two scopes configured:
The relay agent seems to work normally - it forwards the DHCPDISCOVERs to the server continuously (tried many times with ipconfig /renew on the client).
I read many posts about this problem. Some users had other services running on the DHCP server that used the DHCP port, but I don't have such an issue (you see that when the service is stopped, an ICMP port unreachable is sent which is correct). Others however
did not find a solution. Am I missing something? Is there something specific when using the DHCRELAY agent from DHCPD? Can I turn on some verbose logging to track this down? Thanks in advance.

WIth DHCP, there is really nothing to configure. If the Relay Agent/IP Helper is pointing to it, and the VLAN subnet exactly matches the scope subnet, then it should just work.
What I've seen in the VLAN config is either a static route back to the subnet the DHCP server itself is sitting on is not configured or incorrectly configured, or there are ports blocked (need UDP, too, since that's what DHCP uses to pass the OFFER), and
other necessary ports are opened, then it should just work.
Sometimes NIC teaming on the DHCP server will cause it. Not sure. Microsoft doesn't support teaming prior to Windwos 2012, but it doesn't mean that it doesn't work. Don't get me wrong, teaming works nicely, but they just don't support it because they never
certified the drivers, that's all.
The issues I've seen with DHCP relays and VLANs in the forums are usually based on misconfigs in the VLAN or ports blocked. Sometimes we'll refer to call Microsoft Support for specific, hands-on assistance. And searching the threads, from what
I've found that if they did call support, they've never posted back what the problem was based on or the resolution. I can post a couple of them for you to read through, but there were never any response with the actual resolution.
If you like, you also have the option to contact Microsoft Support. Here's a list of phone numbers if you choose this option:
http://support.microsoft.com/contactus/
Ace Fekay
MVP, MCT, MCITP/EA, MCTS Windows 2008/R2 & Exchange 2007, Exchange 2010 EA, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services
Technical Blogs & Videos: http://www.delawarecountycomputerconsulting.com/
This post is provided AS-IS with no warranties or guarantees and confers no rights.

Can I sync email between iPad mini, iPad, and MacBook so that if I delete email using one device, it will also be deleted from the other two?

Can I sync email between iPad mini, iPad, and MacBook so that if I delete email using one device, it will also be deleted from the other two?

You have to set up the email account using IMAP instead of POP.
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I've just moved from PC to Mac, with my PC i and using Vmware Player I used to work on 2 Virtual M/C both on 2 external drives, one Windows Server 2000 as operating system and the sec. WindowsXP, is their a way to open these m/c on my mac

I've just moved from PC to Mac, with my PC i and using Vmware Player I used to work on 2 Virtual M/C both on 2 external drives, one Windows Server 2000 as operating system and the sec. WindowsXP, is their a way to open these m/c on my mac

I am so glad to hear about your success. As you are new to the Mac environment, I will be glad to help you more.
You said: "I can't change the setup yet but i have access". I don't understand what you mean about changing the setup! Please let me know more about that.
I also recommend to use Boot Camp, which allows you to install windows on a partition of your internal hard drive. This has many benefits. First, you can restart your computer and start up in windows. This makes your Mac device a complete windows machine and you gain the most from your hardware when working in Windows. Second, if a problem occures to your Mac OS X, you can restart your machine in Windows and prevent your data from getting lost. Third, you can import the Windows installed on the boot camp partition in to the Mac OS X using VMWare Fusion and work with it as a virtual machine. In this situation, VMWare enables you to work directly with your Windows in the boot camp partition. So it does not create a file package for the virtual machine in OS X.
Regarding the data safety and reliablity, I strongly recommend using Time Machine. You can also set it up to back up your virtual machines or not. This is possible to set up in the Virtual Machine Preferences Page in VMWare Fusion, or in the Time Machine preferences page in the System Preferences app of OS X.
Please don't hesitate to ask any other question. I will be glad to help you.

New 2008 R2 DHCP server will not hand out IP addresses

We've recently migrated our Domain Controllers to 2008 R2, Virtual Machines. (DC3 & DC4).
DC2 is an older 2003 box, 32 bit, set for retirement. All former roles have been moved to DC3 & DC4, including FMSO roles, and the server (DC2) has been demoted. The only service that remains on DC2 is DHCP.
I've used NETSH to export / import the DHCP info to DC4. All reservations have transferred ( Printers) and the scope shows "active" on DC4 and authorized, and running, but whenever I shut DHCP down on DC2, DC4 doesn't start handing out
IP addresses to clients.
Even after rebooting a client multiple times, running ipconfig /release & /renew, it never finds the new DHCP server, nor does the server show any client information in the address leases. (other than reserves)
We have a Cisco ASDM deployed, but DHCP and DNS are both disabled on this device, so I'm not sure IP Helper would be an issue here.
Since both my new DC's are 2008R2, do I need to elevate active directory up to 2008 function before DHCP will work?

Hi,
Is the issue resolved? As suggested by
Wyatt Miller, you can check if it was caused by IP helper.
In addition, is the new server authorized?
Here is a migration guide for you:
Migration of DHCP Server from Windows Server 2003 to Windows Server 2008
http://blogs.technet.com/b/teamdhcp/archive/2009/02/18/migration-of-dhcp-server-from-windows-server-2003-to-windows-server-2008.aspx
Hope this helps.

LAN was down ie Users are not getting ip from DHCP server after enabling DHCP snooping

Hi All ,
Enclosed file has network connectivity diagram.
1. L3 vlan's ie 2,3,4,5 and 6 are configured on ACC-CR1 and ACC-CR2.
2.Trunk is configured between Core switches ( CR1 and CR2) and access switches .VTP mode is transparent on all switches.L2 vlans are configured on all access switches.
3.DHCP is server is located at different location and is reachable over MPLS.
Without enabling dhcp snooping , users connected to access switches (Sw1,sw2,sw3 and Sw4 ) are getting ip address from DHCP server without any problem and everything is working fine.
But users connected to Sw3 and Sw4 are getting ip address from rouge DHCP server which is not pingable from any one of the switch.
So we have configured DHCP snooping for all vlan's on CR1 , CR2 , SW3 and SW4 and "trusted uplink ports" which are connected to WAN routers from CR1 and CR2 and also "trusted uplink ports " of Sw3 and Sw4 which are connected to CR1 and CR2.
As soon we have enabled DHCP snooping and trusted respective uplink ports , users are not getting ip address from remote DHCP server and even users connected to Sw1 and SW2 are facing same issue.
Note : DHCP snooping is not configured on SW1 and SW2.
Why users are not getting ip address from remote DHCP server as soon as we enabled dhcp snooping on Core switches and two access switches ie sw3 and sw4 ? what could have caused DHCP packets to be dropped ? Any idea would be appreciated .

Hi,
as you say: " HSRP is configured between CR1 and CR2 and Vlans are active on CR1" does it mean there are L3 intrefaces configured in each VLAN on your CR switches and ip hepler-address pointing to the remote DHCP server is configured on each of them?
I know it's difficult in a productive environment but IMHO you need to find out where are the DHCP offers dropped.
Either by enabling DHCP debugging or by capturing packets via Wireshark, e.g.
Best regards,
Milan

Two BW systems - one partition/server. How do you divide the resources?

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Running out of available ip addresses

I have a Windows 2012 domain controller on a /24 network. I currently have about 10 free ip addresses. No phones or portable devices on the network currently. Getting ready to automate our warehouse to expand network with 40 or more wireless
hand-held warehouse computers, running windows 8 for handhelds (mostly barcode readers and scanners) and tablet computers. 18 Access points will be installed in about 2 weeks. Need advice on how to update the ip address range of the server. Have
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You don't need to change to a 10. subnet. You could increase the subnet mask on the 192.168.1.0 network to a 23-bit mask. Or you could add a second 24-bit subnet and route between them, with say 4 switches in each subnet. That is the way I would go,
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Multiple ip addresses on one Mac Server

we have 2 ethrnet, 1GB network, on 2 separate switchers, diffierent IP range, what iam looking for is to set the primery eathrnet port on the server and client MAC PRO, only for internet traficing usage, the secondery port use for open directory traffic and file share traffice.
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I will attache an discreption drew concerning my OPEN DIRECTORY on MY SERVER.

By default, every service will listen on every interface, so you're going to need to jump through several hoops to secure your system.
For the most part your answer lies in ordering the interfaces and in routing.
Given a system with two ethernet ports, en0 = 10.1.1.1/255.255.255.0 and en1 = 192.168.1.1/255.255.255.0 with a public router at 192.168.1.254 you should set it up as:
en0:
IP Address 10.1.1.1
Subnet Mask 255.255.255.0
Router: -NONE-
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en1:
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Subnet Mask: 255.255.255.0
Router: 192.168.1.254
DNS: Your INTERNAL DNS servers
Additionally, en1 should be dragged to the top of the list of interfaces.
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Out of available IP addresses on one DHCP server, will other DHCP servers field the request?

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