DHCP

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The Dynamic Host Configuration Protocol (DHCP) is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol. DHCP allows for computers to be configured automatically to communicate with each other over an IP network without the need for manual setup by a network administrator. The implementation of DHCP relies on a DHCP server to hand out network configuration information to DHCP-capable clients that request an IP address (and other information required or useful in communicating with other devices on an IP network). In addition to an IP address, common configuration information served over DHCP includes a default gateway, subnet mask and DNS sever(s).

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I am trying to remove the DHCP and Cert Auth Services from Windows 2008 Enterprise. When I use the remove wizard, it hangs on Initializing Removal. Ive waited and waited, and it never moves off of that. I have tried cmd prompt as well. hangs there as well....Any ideas on what is going on with the remove?
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I currently have my printers with a static IP address, which is the way I want to keep them.  I had a consultant advise me to also enter every printer IP in my DHCP as a reserved IP address, so I've done that a while back.  I just bought 7 new printers I need to configure and I'm thinking do they really need to be added in DHCP and reserve a static IP, which makes no sense, since a static IP is not part of the DHCP range, do I still need to add them in my DHCP scope?

Any thoughts, direction, appreciated.
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adding a device to the stores network drops another device not currently being used. Cant see the DHCP address table but suspect it is at the limit and needs to be bigger agree?
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I did some research on this and didn't come up with a good answer.  So, with the broader experience of EE folks, I'll ask it here:

Assume that there is a single DHCP server of some kind, really any kind, being used.
Assume that there will be some devices that have STATIC IP address settings configured in the host - so these are naturally outside the DHCP range, right?
Assume that there will be some devices that will operate on the network and will have ASSIGNED IP addresses according to their MAC addresses.

The questions are:
Relative to the DHCP server itself (and not your idea of what "should be"):
1) Can the ASSIGNED IP addresses fall outside the scope of dynamic DHCP addresses?
2) Must the ASSIGNED IP addresses fall outside the range of dynamic DHCP addresses?
3) Must the ASSIGNED IP addresses fall inside the range of DHCP addresses (where I dropped "dynamic" because it no longer really applies here).
I figure that the answers may well vary according to the DHCP server (manufacturer or firmware) and I think I've run into that but my memory is fuzzy on the details.

So, answers may vary.
1) Yes, No, sometimes
2) Yes, No, sometimes
3) Yes, No, sometimes

Some things I have learned in the past:
With some Netgear routers, DHCP address allocations become, or may become, ASSIGNED automatically.  This rather assures IP address stability.  
But that's a variation that isn't so important to me right now.

Is there a definition or RFC or...?
Is there a rule…
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How to configure windows DHCP server as a cluster?
I mean, I know how to setup DHCP server, but how to configure it as a cluster?
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Hi,
 
 I am migrating Windows 2012 R2 network to Windows 2019 network. So far I have migrated Active Directory from W2012R2 to 2019 and I need to decide on what to do with DHCP server whether to migrate DHCP server currently running on W2012R2 to W2019 or simply create a new DHCP server on W2019 and uninstall DHCP server from W2012R2.
 
 There are only 6 desktop PCs, several mobiles phones & tablet devices registered in Address Leases.
 Everything else is straight forward in terms of Address Pool: 192.168.10.100 thru 199, Lease duration: 1 day, Scope Options: Router is 192.168.10.1  DNS Servers: 192.168.10.2 .. etc.

 I don't have experience in migrating existing DHCP server to a new server, so I am wondering if it would be wise to create new DHCP server in W2019 and have everyone restart their computers, mobile phones and mobile devices.

 Thanks.
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Win 7 64-bit DHCP client not receiving IP address on WiFi adapter on two separate networks.  If connected to the LAN port it does receive an IP address.  Have tried the built-in WiFi and an external adapter.  

I am getting the following events:

Log Name:      Microsoft-Windows-Dhcp-Client/Operational
Source:        Microsoft-Windows-Dhcp-Client
Date:          5/20/2019 2:56:35 PM
Event ID:      50023
Task Category: Protocol State Event
Level:         Warning
Keywords:      
User:          LOCAL SERVICE
Computer:      I5000.MedicalTeleCommunications.local
Description:
Offer Receive Timeout has happened in the Interface Id 29
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Dhcp-Client" Guid="{15A7A4F8-0072-4EAB-ABAD-F98A4D666AED}" />
    <EventID>50023</EventID>
    <Version>0</Version>
    <Level>3</Level>
    <Task>2</Task>
    <Opcode>31</Opcode>
    <Keywords>0x8000000000000000</Keywords>
    <TimeCreated SystemTime="2019-05-20T20:56:35.915046200Z" />
    <EventRecordID>640</EventRecordID>
    <Correlation />
    <Execution ProcessID="1036" ThreadID="4392" />
    <Channel>Microsoft-Windows-Dhcp-Client/Operational</Channel>
    <Computer>I5000.MedicalTeleCommunications.local</Computer>
    <Security UserID="S-1-5-19" />
  </System>
  <EventData>
    <Data Name="InterfaceId">29</Data>
  </EventData>
</Event>

Log Name:      …
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On windows 2012 R2 servers we have setup the DHCP cluster in the "Hot Stanby" mode to provide redundancy.
But we have noticed that the DHCP reservations do not sync across to the other server.
When I perform a sync for a scope only following tasks are performed and syncing reservations is one of the tasks.

Replicate.JPG
Does it sync only 1 way i.e. from Active member to Passive?
If someone creates a reservation on Passive member will it replicate to Active member?

On one of the posts on internet I read that reservations not replicating is a known problem with DHCP cluster setup and to schedule a task with following command to ensure everything is replicated:-
Invoke-DhcpServerv4FailoverReplication -ComputerName "dhcpserver.contoso.com" -Name "SFO-SIN-Failover" -force

SO I ran this command from powershell on the Active server before scheduling it.
It resulted in the scope going offline and deleted a few reservations. I had to bring it online again manually after the command finished.

Why would the scope go offline?
And why did it delete a few reservation entries. Should I be running that command from Passive member of the cluster?
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We have a Windows domain that operates at the W2K12 functional level.  We recently fixed a mistake of our own making with respect to Dynamic DNS updates from our DHCP server.  We now have A & PTR dns records with the proper permissions (owned by the domain account associated with the DHCP server) in our AD integrated DNS zones.  The problem now is we're left with an unknown number records that are still owned by the computers themselves.  I've done enough spot checking to know there are plenty of these records still out there.

Is there a way to list DNS records that do not have a specific domain account in the ACL for that record?  I want to find every record that domain\dhcpuser does NOT have permissions to.

I need to find these records so I can delete them so they'll be recreated with the proper permissions the next time the computers request an IP from our DHCP server.

My second question is can I directly assign permissions (in DNS mgmt console) for the proper dns zones for my domain\dhcpuser account so it will be able to overwrite any older A & PTR records that were not created with the proper permissions?
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I have a testbed for Domain Controller integration testing with 2 subnets/sites represented.
(The subnets are interconnected and can fairly well communicate).
It's all up and running with a single DC.
Now I'm introducing a 2nd DC which will live on the other subnet/site.
The idea is twofold:
1) local subnet service
2) Dual subnet service should one of the DCs go down.
So far, so good I believe.

In the actual production environment, there is no DHCP server - but I figured I might work with DHCP a bit using the DCs.
But, I can't imagine having two DHCP servers, even on different subnets, if the subnets are interconnected as they are.
Can a single DC perform as a pair of DHCP servers - one for each subnet?
How does it know where a computer resides when interacting (re: site/subnet)?
I have my doubts but figured I'd just ask.....
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DHCP serverHi,
The DHCP server in Windows Server 2008R2 (in SBS2011) stopped working all of a sudden.
I can't expand beyond domain name.
The only  thing I can think of is the fact that I was trying to run DHCP server export command in command prompt.

netsh dhcpserver export E:\user\user_name\DHCP\dhcpdb /all

It could be co-incidental too.
I rebooted SBS2011, but to no avail.
I have backups to restore from if I need to restore files & folders into C:\Windows\System32\dhcp.

Can you help?

Thanks.
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Hello Team,

I want to know the configuration details for the below requirements.

I want to setup a Radius server on Windows Server 2012 R2 STD configured with AD, DNS, DHCP, NPS, CA, IIS etc. to connect Ubiquity (AC Pro)Wireless SSID on non-domain laptop and mobile devices (android and Iphone) using an External certificate.  but the condition is the mobile users or laptop users should not have any authority to copy/export  this certificate to another devices.

please help me on this case. thanks in advance
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We recently provisioned a new Windows Server 2016 VM on a network with an existing Windows Server 2012 R2 VM that is the current DC and DHCP server. The intention was to transition all of the roles to the new VM. The question here is with regards to the DHCP portion.

We successfully set up the new VM as a DHCP failover partner and verified it was serving DCHP requests. We then decommissioned the old DC and now the new server is running DHCP with its partner (the old server) as down/failed.

The question is this: how do I change the config so that there is no longer a replication/failover partner with DHCP?

Thanks in advance!
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Earlier this week I started setting up an RDP Gateway on a Windows 2016 Essentials Server so a few employees could remote in.  I did this by going to “Add Roles”…., which I’ve since found out I should have done via the Dashboard.  OK.  

Anyway, this morning the office called and said nobody could access the server, and several didn’t have Internet access.  I was able to remote into the server and looking at the logs I could see there were problems with the DHCP.  We got the DHCP Server to start (removed the role and re-added it) but can’t get the DHCP Client service to start as we always end up with the error “Error 5: Access is Denied”.  

We started looking at the permissions in the registry and comparing them to another server of the same specs, and they were all screwed up.  So I started adding back things like “System”, “Network Service”, etc.  Still end up with the “access denied” error.  In the Server Manager Dashboard, there are 8 services that aren’t running.  They are:  Diagnostic Policy Service, Network Location Awareness, DHCP Client, IP Helper, Base Filtering Engine, Downloaded Maps Manager, and Windows Firewall.  Several of them give me the “access denied” error when trying to start, while others (like Network Location Awareness” won’t start because their dependency service or group failed to start.

One of the errors that I’m seeing in the logs is " The DHCP service is not servicing any DHCPv4 clients because none of the active network interfaces have …
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Greetings.
We are currently carrying out server virtualization and consolidation project of our domain controllers. We have;
    one domain we could call security.local with 3 domain controllers for the security department, Domain functional level is currently on server 2008 and Forest functional level is on server 2003.
      4 domains we could call;
             
        aci.local( 2 DCs, Forest function = 2003, Domain Function = 2012R2)
                [list=2][/list]aci2.local(2 DCs, Forest function = 2003, Domain function = 2003)
                [list=3][/list]aci3.local( 2 DCs, Forest function = 2003, Domain function = 2012R2)
                [list=4][/list]aci4.local( 1 DC, Forest function = 2003, Domain function = 2012R2)
        For the Engineering department

        There are no DHCP servers in any of the domains, but all domain controllers have DNS service.

        Our requirement is to migrate and consolidate the above design using the newly set up VMWare datacenter and highlighting on security and segregation of the 2 departments, so please advice on how we should approach this. We thought about setting up a new Root domain with 2 domain controllers and creating 2 child domains for both departments and creating an active directory design that consolidates engineering domains into OUs and using the Active Directory Migration Tool to do an inter\cross forest migration of computer and user accounts.
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        After upgrading our Cisco Communications Manager to 12.5.1, we have SOME phones that are unable to get an IP address from the publisher or subscriber.  Additionally, with some other models we needed to power cycle the phones.  The model most affected is the 7841, but not all of them are problematic.  We have factory reset a bunch, set static ip addresses, all to no avail.  I am interested in what could be the issue with DHCP and any steps I should take to fix it.  The phones in question are typically stuck at "verify your network settings" screen or some other network message.

        We have a case open with TAC, but I wanted to get real live end user suggestions.  Thank you for any assistance you can provide EE!
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        In several of our WSE 2012 R2 networks, one or more of the workstations are laptops, which serve dual purposes.  They function as a network workstation on the Essentials domain office network.  In that environment, the laptops are set up with the standard Essentials configuration (e.g., DNS service provided by the Essentials server, which has a fixed IP address, etc.).  That works fine until the second laptop purpose is invoked.

        The management personnel that have laptop workstations also need to use them when they travel.  When used this way, they primarily connect to wireless networks.  Unlike the office Essentials domain network, when traveling, the laptops obtain everything (including DNS) from the wireless router in each location.  The first problem we encountered was that the traveling laptop could not access the Internet, although it was connected to the wireless network with strong signal strength.  Apparently the laptop was trying to reach the fixed IP address of the domain server, which of course was nowhere to be found.  Without working DNS, the laptop was unable to reach any destination on the Internet (such as google.com, msn.com, etc.).  The only way we were able to work around this was to manually change the DNS source setting from "always obtain DNS" from the server to having DNS automatically assigned by the wireless router.

        On the flip side, when the laptops returned home to the WSE domain office network, they experienced frequent problems with mapped …
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        Hello IT people 😁
        I need to build a data center. from servers point of view, how to do or what is the best practice for the followings:
        1- for the DHCP I Need the setup to be HA or Cluster.
        2-for WSUS I Need the setup to be Cluster.
        3-for  SMTP I Need the setup to be HA.
        4- for MYSQL DB I Need the setup to HA with Sync.
        5-For NTP I Need the setup to be HA or Cluster.
        6-For AD please note that's required to moving FSMO, maybe TLS needed, trust configuration between Server Farm and DMZ domains if used and GPO for all Systems.


        feel free to ask any questions to help me 😅
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        I work in a corporate environment. I am based in the USA, corporate IT is in Germany. They image all of our computers via Matrix42. We have received a batch of new HP Elitebook 850 G5 laptops. I have them on our network and powered on. I have accessed the BIOS via F10 and have found that the PXE boot is enabled, but Germany does not see it. When the laptop boot, normally I would see the startup screen indicating IP addresses, DHCP info, etc. With the new batch, all I see is 'Protected by HP Secure Start'. I have access to the internet, so I know I am on the network. I can run IPCONFIG /all and see all my network info.

        How do I configure this laptop for Network PXE boot?

        Thanks in advance.
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        DHCP Logging Question:  I am running DHCP services on a Windows Server 2016.  I would like to know how I can capture all of the DHCP log activity for an indefinite amount of time in a format that humans can read.  Any suggestions are appreciated.
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        Could someone please help me understand what needs to be done transitioning from Cisco VOIP to Avaya?  Specifically, Option 242 that needs to be configured on DHCP Voice Pool? The client claims that the phones are staying in Data Vlan (Vlan 1) and not going over to Voice Vlan (Vlan 900).

        The setup is pretty straight forward. There is one building (3 closets total) and only 2 Vlans: Data and Voice.  

        Vlan 1 10.12.0.0/16 Data
        Vlan 900 10.13.0.0/16 Voice

        The Cisco 2921 Router is configured for Voice DHCP like this:
        !
        ip dhcp pool VOIP
         network 10.13.0.0 255.255.0.0
         default-router 10.13.0.1
         option 150 ip 10.13.0.10
         dns-server 4.2.2.2

        10.13.0.10 is the Call Manager IP.

        I believe there is an Avaya server (controller) onsite that will be acting as DHCP for the new Avaya phones.

        What needs to be done for the Avaya phones to obtain 10.13.x.x IP addresses and not 10.12.x.x ? I've read about Options 242 (or 176) that need to be configured but I'm not sure how to go about it. I haven't really worked with Avaya phones before.

        What about LLDP? The switches are Cisco, 2960x. Switchport are configured to access vlan 1 and Voice vlan 900.

        Any help would be appreciated!
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        I have a Vlan set in one Layer3 Dell 6248 switch, this vlan purpose is to connect our PBX, I have two subnets, my Native has the scope 192.168.16.0/24 and the vlan 7 has 10.11.0.0/24 now if I have my facts right I created the vlan in the switch  and gave it IP 10.11.0.5 255.255.255.0 with IP Helper Address 192.168.16.40 that in it self should be able to route to my DHCP server where I created the 10.11.0.0 scope, I think that I have everything cover so I can plug phones into the switch and they will be able to reach the 10.11.0.0 subnet to get an IP from that scope but I connect the phones that are programmed to look for vlan 7 and they cannot reach, but some of my devices that are in 192.168.16.0 scope are reporting to the  10.11.0.0 scope, can anyone help me to understand what did I do wrong ?
        Switch.JPG
        DHCP.JPG
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        I want to document DFS within an organisation, whats best way to do this?

        I have good notes on AD, DHCP, DNS etc just looking for DFS

        Environment is 2012 r2 environment

        Found this

        https://gallery.technet.microsoft.com/List-Distributed-File-3f399d9d

        Any other ways appreciated
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        I'm still having issues getting my new server fully online. I created my new domain on Windows Server Essentials 2016, and migrated all the computers from the Windows Server 2012 domain onto the new domain.

        Everything seems to be working except for DNS/DHCP. I have to set a static IP as well as define an outside DNS server such as 1.1.1.1 in order to get internet on my devices.

        If I power back on the old server which no devices are connected to, I can connect to the internet without settings a static IP or DNS server.

        I'm thinking there's a problem with the DNS on my new server, though I'm not sure what it is. The server is brand new, on a new domain as the primary DC. I migrated the DHCP settings from the old server and adjusted them to remove references to the old server, and set references to the new server.

        When I run dcdiag /fix I get the following output:

        Starting test: SystemLog
                 An error event occurred.  EventID: 0x0000168F
                    Time Generated: 04/04/2019   22:05:16
                    Event String:
                    The dynamic deletion of the DNS record '_kerberos._tcp.dc._msdcs.ad.domain.com. 600 IN SRV 0 100 88 SVR-HVDC1.ad.domain.com.' failed on the following DNS server:
                 An error event occurred.  EventID: 0x0000168F
                    Time Generated: 04/04/2019   22:05:16
                    Event String:
                    The dynamic deletion of the DNS record '_kerberos._tcp.Default-First-Site-Name._sites.dc._msdcs.ad.domain.com. 600 IN SRV 0 100 88 
        

        Open in new window

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        a client has a Hyper V machine, server 2012 r2 standard.  this acts as their Domain Controller, recently they ran out of IP addresses and a new PC wouldn't get an IP address, so we expanded the scope from 1.1 - 1.200 to 1.1 - 1.254 so it gives them more IP's.  obviously they have servers with static IP's of .222 etc so we made sure all these would be put as reservations for those devices (i believe they were exclusions anyway).  when we did all of that the problematic PC got an IP and it was fine,  this morning the client has come in to say that the PC hasn't got an IP address again, in DHCP the lease is still valid for that machine, so i deleted it, got the PC rebooted and then it got an IP address, the same IP as it had the day before.

        can anyone shed some light on this issue and why it would do this?
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        DHCP

        10K

        Solutions

        15K

        Contributors

        The Dynamic Host Configuration Protocol (DHCP) is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol. DHCP allows for computers to be configured automatically to communicate with each other over an IP network without the need for manual setup by a network administrator. The implementation of DHCP relies on a DHCP server to hand out network configuration information to DHCP-capable clients that request an IP address (and other information required or useful in communicating with other devices on an IP network). In addition to an IP address, common configuration information served over DHCP includes a default gateway, subnet mask and DNS sever(s).