Removing DHCP failover removes DNS A records
We are running a windows 2012 r2 domain with 4 DCs all configured as DNS servers. One of the DCs is also our DHCP server. We configured a second dhcp server in January and joined it in failover mode. It was fine for a couple weeks, but then we got spammed
with 20291 and 20292 errors. We decided to remove the failover relationship and unauthorize the second dhcp server which we did without any errors. However when we rebooted the original dhcp server, we immediately lost over 30 A records in dns, mostly printers,
and we found that the dns server ip addresses on the nics of the dhcp server were changed to invalid addresses. Is there anything known that could explain this behavior? Otherwise the server seems to be working fine, and diagnostics (dcdiag, repadmin, event
log) are not showing any errors.
Hi,
Was the second DHCP server also a DC? Which kind of DHCP Failover Modes did you used?
Based on my experience, a DHCP server can register and update DNS PTR and address A resource records on behalf of its DHCP-enabled clients. I assume the lost A
records may be due to the IP address of the DNS server was changed. Did you configure a static DNS server in the DNS settings on the DHCP server? I assume that you select "Obtain DNS server address automatically" as if you define a DNS
server, it won't be changed after reboot.
In general, it would be better to point the preferred/secondary DNS server to the DC instead of obtaining the DNS server address automatically.
Besides, for event ID 20291, you can refer to the KB below:
http://support.microsoft.com/kb/2955135
Best regards,
Susie
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Similar Messages
-
DHCP Reservation Sync and DNS Host record sync etc shown in IPAM GUI
Hello all,
I am aware of the scripts in the TechNet script center to sync DHCP leases etc to IPAM, however my question is about something else -
If you highlight an IP address (IP address inventory->select an IP), You can see fields that say: "DHCP reservation sync", "DNS PTR record sync" and "DNS host record sync" as below:
I was curious as to what these are for. Is there some built-in sync functionality for these that I perhaps have not enabled? (Don't see such options any where..)
thanks,
-RaviHi Ravi ,
The three columns tell us the information of the synchronization between IPAM server and DNS server (or DHCP server) .
Here is the detailed guide for using IPAM :
Using the IPAM Client Console :
https://technet.microsoft.com/en-us/library/jj878351.aspx#inventory
IPAM can sync DNS and DHCP records .
The IPAM database is separate from DHCP and DNS servers on our network ,and full synchronization of hosts and IP addresses between IPAM and managed DNS or DHCP servers does not occur automatically
unless we have configured automated tasks to perform this synchronization .
For detailed information ,see
DNS and DHCP record synchronization chapter in the following link :
Multi-server Management :
https://technet.microsoft.com/en-us/library/jj878329.aspx
Best Regards,
Leo
Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact [email protected] -
DHCP Name Protection & DNS Records
How correlates DHCP Name protection & DNS records for domain PC? We found a lot of old records from PC's in DNS, and I'm just wondering, does DNS (or DHCP) removes records about PC, which were removed from AD (not gracefully, just deleted computer
account)?Hi,
If you want the DHCP server to register the DNS records for the DHCP clients, you need to configure the DNS configuration and options settings on DHCP server. In addition, it seems that Windows DHCP clients cannot update their records with the DNS server themselves,
but DHCP server can be configured to perform updates for both Windows DHCP clients and non-Windows DHCP clients. The links below may be helpful to you:
[Forum FAQ] DNS Dynamic Update Troubleshooting Guide
DHCP and DNS
Best regards,
Susie -
Procedure to remove DHCP service off a Windows 2008R2 Cluster.
I cannot seem to find a procedure to remove DHCP off the Windows 2008 R2 Cluster.
I am not sure which comes first Delete the DHCP cluster service or uninstalling the role.
Thank you.Hi,
Based on my exprience, it would be better to removal of the DHCP failover relationship firstly. Because if you remove the DHCP server role firstly, then you cannot communicate with the partner server. In addition, deleting a failover relationship that has
DHCP scopes associated with it will remove those scopes from the partner DHCP server, and the scopes will remain on the DHCP server where the failover relationship was deleted. So you can do that on the DHCP server that you want to keep. For detailed
information, please refer to the article below:
https://technet.microsoft.com/en-au/library/dn338986.aspx#delete
Then after you renew leases on the clients and make sure that only one server is responding to DHCP requests. After that, you can uninstall the role.
Best regards,
Susie
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Removing background "noise" from an interview recording
Hello!
I was wondering if it was possible on Soundtrack Pro to remove continuous background "noise" from a recorded interview? An example would be someone clicking a pen or a tapping his foot during the duration of the interview. Any advice would be extremely helpful.
Thanks so much!
TedIt can, but what you are describing are not continuous, but points of sound. Continuous refers more to hums and vibrations, things like air conditioner noise or the sound of traffic. That said you can still give it a try. You can also try running the click and pop filter and see what you get.
Regarding these point sources I have better luck removing them with Adobe's Soundbooth. Their cascading frequency display allows you to draw irregular shapes around sounds like these and then extract them without disturbing the other sounds around them.
Take a look at the manual.
Good luck -
DNS on Server 2008 R2: DNS A records strangely disappear
Hello,
I am experiencing very strange problems with my DNS (Server 2008 R2, AD integrated). Several A records for Windows clients are missing, and even if I register them as static they somehow disappear again. However, the AAAA records are still around (IPv6 is
running in default configuration, I haven't touched that at all), but another strange thing here is, most of them are listed as STATIC records.
At present, the DHCP server is set to NOT register the clients with DNS. DNS accepts only secure updates, scavenging is disabled. (I am somewhat reluctant to disable dynamic updates on the DNS server completely because I think the DCs register and update
lots of records dynamically). When I register all missing A records, most affected clients loose it again within an hour or so but some seem be fine. It seems to me that about 20 % of the clients are affected.
I have enabled Directory Service Changes auditing, and its in fact the machine account which appears to be responsible. Clients with A records generate 10 entries (ID 5136) in the DC's security log while the problematic clients generate only the
first 5 events. So it appears to me that they can delete the record but not create a new one. All clients are set to register themselves with DNS.
As far as I remember I had Windows clients with missing A records in the past once in a while but the problem became really serious only about one and half weeks ago.
Does anyone have an idea of what might be going on here? Can I safely disable DNS dynamic updates without adversely affecting AD/DC functionality? Generally, we don't actually need dynamic updates.
Cheers, Georg.What operating system are the clients?
I would like to first point out how registration works with static and DHCP, and the differences depending on how DHCP is configured.
=====================================================
1. By default, Windows 2000 and newer statically configured machines will
register their own A record (hostname) and PTR (reverse entry) into DNS.
2. If set to DHCP, a Windows 2000, 2003 or XP machine, will request DHCP to allow
the machine itself to register its own A (forward entry) record, but DHCP will register its PTR
(reverse entry) record.
3. If Windows 2008/Vista, or newer, the DHCP server always registers and updates client information in DNS.
Note: "This is a modified configuration supported for DHCP servers
running Windows Server 2008 and DHCP clients. In this mode,
the DHCP server always performs updates of the client's FQDN,
leased IP address information, and both its host (A) and
pointer (PTR) resource records, regardless of whether the
client has requested to perform its own updates."
Quoted from, and more info on this, see:
http://technet.microsoft.com/en-us/library/dd145315(v=WS.10).aspx
4. The entity that registers the record in DNS, owns the record.
Note "With secure dynamic update, only the computers and users you specify
in an ACL can create or modify dnsNode objects within the zone.
By default, the ACL gives Create permission to all members of the
Authenticated User group, the group of all authenticated computers
and users in an Active Directory forest. This means that any
authenticated user or computer can create a new object in the zone.
Also by default, the creator owns the new object and is given full control of it."
Quoted from, and more info on this:
http://technet.microsoft.com/en-us/library/cc961412.aspx
=====================================================
Therefore, based on that, even if you have DHCP set to not register, and the clients are 2008/Vista and newer, then DHCP is doing it. That explains why you see the system account doing it.
Now, I think it will actually help you if you configure DHCP to register everything, configure credentials, and add the DHCP server computer object to the DnsUpdateProxy group. Don't add anything else to this group.
This way DHCP controls everything and it's easier to track AND more importantly, DHCP can update already registered records.
====================================================
In summary:
DHCP DNS Update summary:
- Configure DHCP Credentials.
The credentials only need to be a plain-Jane, non-administrator, user account.
But give it a really strong password.
- Set DHCP to update everything, whether the clients can or cannot.
- Set the zone for Secure & Unsecure Updates. Do not leave it Unsecure Only.
- Add the DHCP server(s) computer account to the Active Directory, Built-In DnsUpdateProxy security group.
Make sure ALL other non-DHCP servers are NOT in the DnsUpdateProxy group.
For example, some folks believe that the DNS servers or other DCs not be
running DHCP should be in it.
They must be removed or it won't work.
Make sure that NO user accounts are in that group, either.
(I hope that's crystal clear - you would be surprised how many
will respond asking if the DHCP credentials should be in this group.)
- On Windows 2008 R2 or newer, DISABLE Name Protection.
- If DHCP is co-located on a Windows 2008 R2, Windows 2012, Windows 2012 R2,
or NEWER DC, you can and must secure the DnsUpdateProxy group by running
the following command:
dnscmd /config /OpenAclOnProxyUpdates 0
- Configure Scavenging on ONLY one DNS server. What it scavenges will replicate to others anyway.
- Set the scavenging NOREFRESH and REFRESH values combined to be equal or greater than the DHCP Lease length.
References:
This blog covers the following:
DHCP Service Configuration, Dynamic DNS Updates, Scavenging, Static Entries, Timestamps, DnsUpdateProxy Group, DHCP Credentials, prevent duplicate DNS records, DHCP has a "pen" icon, and more...
Published by Ace Fekay, MCT, MVP DS on Aug 20, 2009 at 10:36 AM 3758 2
http://msmvps.com/blogs/acefekay/archive/2009/08/20/dhcp-dynamic-dns-updates-scavenging-static-entries-amp-timestamps-and-the-dnsproxyupdate-group.aspx
Good summary
How Dynamic DNS behaves with multiple DHCP servers on the same Domain?
http://social.technet.microsoft.com/Forums/en-US/winserverNIS/thread/e9d13327-ee75-4622-a3c7-459554319a27
Another good Summary:
Thread: "DNS problem" December 18, 2013
http://social.technet.microsoft.com/Forums/windowsserver/en-US/37b8b6b3-6cb1-496c-8492-09ded13bab18/dns-problem?forum=winserverNIS
Another good discussion that Microsoft support concurred with my settings for a poster that called in to Support, which verified my configuration suggestions in my blog are correct:
DHCP Server Not Registering A Records for Windows Clients
http://social.technet.microsoft.com/Forums/en-US/winserverNIS/thread/e4b285d6-5795-4045-83ff-3a3c793b2cfc/
Ace Fekay
MVP, MCT, MCSE 2012, MCITP EA & MCTS Windows 2008/R2, Exchange 2013, 2010 EA & 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services
Complete List of Technical Blogs: http://www.delawarecountycomputerconsulting.com/technicalblogs.php
This posting is provided AS-IS with no warranties or guarantees and confers no rights. -
Hi,
We are having an issue where DNS Host records seem to be missing, a user logs on and they don't get their group policies. They can logon again and get their group policies. However the DNS Host record is still not created on the DNS Servers.
If we reboot the PC the DNS record is created. What is going on.
We have 2 DC's running DNS, and one of them runs DHCP.Hi,
According to your description, my understanding is that client does not registry record in DNS server when user logon. And the DNS record will be created after rebooting the client.
DNS updates can be sent for any of the following reasons or events:
1. An IP address is added, removed, or modified in the TCP/IP properties configuration for any one of the installed network connections.
2. An IP address lease changes or renews with the DHCP server any one of the installed network connections. For example, when the computer is started or if the
ipconfig /renew command is used.
3. The ipconfig /registerdns command is used to manually force a refresh of the client name registration in DNS.
4. At startup time, when the computer is turned on.
5. A member server is promoted to a domain controller.
A user logon behavior will not trigger DNS update/registry. You may Open CMD on client and type
ipconfig /registerdns command to manually force a refresh of the client name registration in DNS.
If I have any misunderstanding about your question, please correct.
Best Regards,
Eve Wang
Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact [email protected] -
Just implemented 2012 DHCP Failover using the Hot-Standy model. I set the Maximum Client Lead Time to 1 hour.
My clients are getting the initial lease with an expiration of 1 hour. Then after the hour, they disappear from DHCP and DNS but they still have the address. Any ideas?I am also having a similar issue after implementing DHCP Failover. I configured it with default settings (1 our MCLT, 8 day leases, %5 IP reserve). I tested the fail over and it worked. Clients received new addresses from the standby. I then started the
DHCP service on the primary and all seemed well. However, a short time later about a dozen hosts seem to have lost their DNS A records.
These machines have DHCP leases that began before the failover was tested and expire days after. They did not actually ever attempt to renew DHCP at this time (to my knowledge). I think this may be a bug or somehow related to the DNS configuration on the
scope. It is currently set to "Always update" and I may change to Dynamically update if requested, and test failover again. -
DHCP Failover in Windows 2008 R2 and Windows 2012 R2 Environment
Hi Everyone,
We are trying to implement DHCP failover in our environment. Our IT Infrastructure consists of 4 – windows server 2008 R2 servers and 7 – Windows Server 2012 servers; 1 Main Office with 2 – DC’s and 9 branch/remote offices with one DNS server in every remote
office. All the DNS servers have 2 scopes defined on them for VOICE and Data with different Subnets.
What would be the best method to implement failover in 2008 R2 – Windows Failover Cluster or Split scope? And how to implement DHCP Failover in Windows Server 2012 R2?
Please let me know if you need more information.
Thank you for your help!
-kNHi,
if you can choose between 2008 R2 and 2012 R2 than go with 2012 R2 it is easy to create a DHCP failover there. Actually that is one of the new features of Windows 2012.
With Server 2012 you setup your fist DHCP server with the scopes you want to setup. Than you install the second 2012 server with DHCP role and authorized. If you have done this you going back to your first server, where you already configured your scopes.
Now right click onto the scope you want to setup for failover and select 'Configure Failover'. You can than set it up as kind of split scope (Load balance Mode) or as real fail over setup (Hot Standby). In Load balance Mode you can configure the balance of
IP addresses between the both servers, like primary has 60% IP addresses and secondary has 40%.
With Server 2008 R2 the easiest configuration is split scope. But here it depends how many IP leases you will max have and if you can absorb if one of the server is going down. Lets say you have 50 DHCP leases max, than sure, set it up as split scope. But
if you have 200 DHCP clients, than I would go with failover cluster. At the end it depends on your environment.
Sven -
I am attempting to implement DHCP failover using load balancing with an Essentials and a Standard server. I have everything configured and working but I am facing an issue.
If I try to start the DHCP services on the Essentials server and the DHCP services on the Standard server are already started it will not start and I get error 1053 The DHCP/BINL service has encountered another server on this network with IP Address, 192.168.1.3,
belonging to the domain: . in the event log on the Essentials serve.
Any ideas why this is?In a network of this size there is little need for multiple or failover DHCP servers. With a lease time in the one week category the chances that the server will be off line at the same time that clients need to renew are pretty slim. Should
the server simply be unavailable you can turn the DHCP on the router, or, as you intend, on the second server.
Larry Struckmeyer[SBS-MVP]
Larry, I am not sure I find this to be the case -- that rarely will the server be off at the same time clients need to renew. I volunteer support to a local non profit. Sadly, it's not uncommon for the Essentials server to not come up cleanly
after a Microsoft Update or a power outage. With DHCP not available on the WSE2012 server, employees who come in and fire up their laptops will in some cases hit the lease expiration. I'll get a phone call, and now there will be two frustrated
people. :-)
I *could* return to letting the router handle DHCP, but I've read too many times on technet and social forums the rather forceful recommendations by microsoft people that an Essentials served network should have DHCP running on the server.
I feel I'm stuck between a rock and a hard place. The strong recommendation from microsoft is to always serve BOTH DHCP and DNS from a WSE server. However, there appears to be no DHCP failover option for WSE, which will make my users unhappy
(and strain my volunteerism!).
Thoughts?
I've tried to research whether WSE will allow a router to act as a failover in hot standby mode, but haven't succeeded. (I'll then need to find a router that supports hot standby in a WSE environment.)
(I realize I am quite late to this thread. Hopefully that's not a problem.)
Steve -
Windows 2012 DHCP Failover "Lost contact with partner"
We have stood up a pair of Windows 2012 DHCP servers and configured DHCP failover (in Load Balancing mode) as per the Microsoft Technet article. The two servers are on the same subnet, and time is in sync between them. Almost immediately after
configuring scopes to failover, one node loses contact with the other, and the alternate node goes to failover mode "Recover".
We have restarted both servers and services. Both DHCP servers show as available. Clicking "Replicate Failover Scopes" completes successfully with no errors, and the only two warnings in the Event Log are about credentials for Dynamic
DNS updates and a dynamic IPv6 address (which we don't use at all.)
How come they can replicate, but have "lost contact"; and how do we get the one out of "Recover" mode?You should see Recover state only if one of the DHCP server actually went down and came back up. In this case the server which comes back up would be in Recover state but will transition to Recover_Wait state and come back to Normal after it syncs it
leases. This should be relatively quickly. Did your servers continue to remain in the Lost Contact...\Recover state for long.
Did you see any events in the DHCP Server admin channel
Microsoft\Windows\DHCP Server\Admin.
You can also enable AuditLogs (Microsoft\Windows\DHCP
Server\AuditLogs) which logs all the server to server messages. You can enable the log by right clicking on
Microsoft\Windows\DHCP Server. View->Show Analytical and Debug Logs. This will show the
Microsoft\Windows\DHCP Server\AuditLogs in event viewer. You can then right click and enable the log and see if there are any failures
being logged there. -
Unable to run the application via DNS CName record.
I have Windows Server 2008R2 running an application that connects to a database via a DNS CNAME record. The application was working fine until after yesterday when it could no longer
connect to the database. The database server is up and running without any issues. You have verified remote connectivity to the database server from your workstation.
How would you troubleshoot the issue and what are the steps to resolve it?It might be that the application does not support using aliases for DNS resolution. You will need to contact your application developer/vendor for assistance.
To make sure that DNS resolution works properly from the infrastructure level, you can simply use
nslookup and make sure that the resolution is done properly.
This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.
Get Active Directory User Last Logon
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Reset Active Directory user password -
TCP connection for DHCP failover frequently are broken in Solaris 10
Hi
We have two dhcp servers which are installed in Solaris 10 and set to a failover pair. Currently, we can find that tcp connection for dhcp failover protocol are frequently broken. It looks like that primary dhcp server initiatively send FIN message to secondary one but in general, this tcp connection should always keep alive. On the other hand, the tcp connection can not completely be closed right now which FIN_WAIT_2 status in Primary one and CLOSE_WAIT status in secondary would last for a long time.
Will Solaris 10 cause this fault? Is it a known bug in OS?
OS info:
-bash-3.00$ cat /etc/release
Solaris 10 5/08 s10s_u5wos_10 SPARC
Copyright 2008 Sun Microsystems, Inc. All Rights Reserved.
Use is subject to license terms.
Assembled 24 March 2008
-bash-3.00$
-bash-3.00$
-bash-3.00$ uname -a
SunOS edns1 5.10 Generic_142900-03 sun4v sparc SUNW,Netra-T5220
TCP connection info:
Primary DHCP Server:
2012 08 29 03:41:43
PING 172.25.6.137: 56 data bytes 64 bytes from edns2 (172.25.6.137): icmp_seq=0. time=0.678 ms
remote refid st t when poll reach delay offset disp
==============================================================================
*idns1 195.26.151.151 3 u 45 1024 377 0.75 -0.071 0.05
+idns2 195.26.151.151 3 u 162 1024 377 0.93 0.169 0.08
clusternode1-pr 0.0.0.0 16 - - 1024 0 0.00 0.000 16000.0
+clusternode2-pr idns1 4 u 406 1024 376 0.49 -0.154 15.12
172.25.6.133.647 172.25.6.137.58107 49640 0 49640 0 ESTABLISHED
172.25.6.133.647 *.* 0 0 49152 0 LISTEN
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2012 08 29 03:41:47
PING 172.25.6.137: 56 data bytes 64 bytes from edns2 (172.25.6.137): icmp_seq=0. time=0.535 ms
remote refid st t when poll reach delay offset disp
==============================================================================
*idns1 195.26.151.151 3 u 49 1024 377 0.75 -0.071 0.05
+idns2 195.26.151.151 3 u 166 1024 377 0.93 0.169 0.08
clusternode1-pr 0.0.0.0 16 - - 1024 0 0.00 0.000 16000.0
+clusternode2-pr idns1 4 u 410 1024 376 0.49 -0.154 15.12
172.25.6.133.647 172.25.6.137.58107 49640 0 49640 0 FIN_WAIT_2
172.25.6.133.647 *.* 0 0 49152 0 LISTEN
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Secondary DHCP Server:
2012 08 29 03:41:41
PING 172.25.6.133: 56 data bytes 64 bytes from edns1 (172.25.6.133): icmp_seq=0. time=1.26 ms
remote refid st t when poll reach delay offset disp
==============================================================================
*idns1 195.26.151.151 3 u 450 1024 377 0.92 -0.067 0.06
+idns2 195.26.151.151 3 u 552 1024 377 0.96 0.237 0.08
+clusternode1-pr idns1 4 u 360 1024 377 1.85 -0.528 1.51
clusternode2-pr 0.0.0.0 16 - - 1024 0 0.00 0.000 16000.0
172.25.6.137.647 *.* 0 0 49152 0 LISTEN
172.25.6.137.58107 172.25.6.133.647 49640 0 49640 0 ESTABLISHED
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2012 08 29 03:41:45
PING 172.25.6.133: 56 data bytes 64 bytes from edns1 (172.25.6.133): icmp_seq=0. time=1.36 ms
remote refid st t when poll reach delay offset disp
==============================================================================
*idns1 195.26.151.151 3 u 454 1024 377 0.92 -0.067 0.06
+idns2 195.26.151.151 3 u 556 1024 377 0.96 0.237 0.08
+clusternode1-pr idns1 4 u 364 1024 377 1.85 -0.528 1.51
clusternode2-pr 0.0.0.0 16 - - 1024 0 0.00 0.000 16000.0
172.25.6.137.647 *.* 0 0 49152 0 LISTEN
172.25.6.137.58107 172.25.6.133.647 49640 0 49640 0 CLOSE_WAIT
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Thanks!Thanks, but had found a previous discussion with this hint and applied it.
svccfg -s sendmail listprop shows config /local_only = false
Yes, I would really love to fix the fault, but what I would really like is some hints as to how to debug ports under svc control. -
Unable to replicate reservation to DHCP failover cluster partner node
Hello.
After reading that whilst DHCP address leases are replicated automatically to DHCP failover cluster partner nodes, and that reservations aren't, I followed steps to right-click the scope from the server which features the specified reservation, and select
'Replicate Scope'. The status window detailing the progression of associated tasks shows that replication of reservations to my other node partner, failed. The error code returned was 20022, which states that the specified IP address is currently taken by
another client.
Why is this occurring? The other node I am trying to replicate to, is within the DHCP failover cluster, and so should be aware that the reservation I am trying to replicate is linked to the same device? Why am I unable to replicate the reservations?
Any help would be appreciated.
Many thanks.Hi,
Based on my research,
DHCP Failover automatically synchronizes leases between failover partners in Windows server 2012 and Windows Server 2012 R2. However, configuration changes on one server in the failover relationship do not automatically get replicated
to the partner, you need to manually replicate by choosing the “Replicate Scope…”
or “Replicate Relationship…” option in DHCP Server.
In addition, for DHCP failover to function correctly, time must be kept synchronized between the two servers in a failover relationship. Please check if the time is synchronized between the two servers.
Besides, you can check the event log to see if any other related information exists.
Best regards,
Susie -
How to test Windows 2012 R2 DHCP Failover without shutting down the service?
How can I test the Win2012R2 DHCP Failover?
There is a command or script, that i could use to test if DHCP failover is working properly?
How to monitor the sync of the objects?
How to make sure that it will do the job, if required?
Or i have to really stop DHCP server main server and see the failover?Hello,
you have to keep in mind that this has ONLY effect for machines that request during the downtime a lease. So if your lease time is for example 8 hours a computer will ask after 4 hours for the renewal of the lease.
Means there is no problem for running machines during the test. You just need a computer to start after the service is shutdown on the first DHCP server, should take only some minutes to check if the fail over works. Then you could already start the service
again if you see the lease on the new server.
Best regards
Meinolf Weber
MVP, MCP, MCTS
Microsoft MVP - Directory Services
My Blog: http://blogs.msmvps.com/MWeber
Disclaimer: This posting is provided AS IS with no warranties or guarantees and confers no rights.
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