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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Hi
We have Ruckus wireless network and I have 2 working  SSID.
SSID-A is on VLAN 81
SSID-B is on VLAN 82

My predecessors had setup a NEW SSID which is on VLAN 83  and it is not working.
When I connect my laptop to SSID-A or SSID-B it gives the IP address from that particular subnet.

If I connect my laptop to the NEWSSID, it says limited activity with yellow exclamation mark and gives APIPA 169.254.65.204 IP address.
There is a trouble shooting option with the Ruckus wireless controller using a mac address of the laptop and when testing the DHCP request fails and It looks like the NEW SSID is not set up properly to reach the DHCP server.

So our edge switches are POE Cisco switches and I would like to see the edge switches if they are set with DHCP helper address for VLAN 83
Please let me know the cisco command to view the VLAN configuration of VLAN 83 .
Or let me know if there is any better way of trouble shooting this issue.

Thanks and any help will be great.
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SCCM 2012, PXE boot stops working. I have SCCM version 1806.
The contact with DHCP gets the IP address, next download WDSNBP from my SCCM server.  Everything looks working fine until I got the line "Press F12 for network service boot".
 if I press F12 I got this error: " The Windows Boot Configuration Data (BCD) file from the PXE server does not contain a valid operating system entry. Ensure that the server has boot images installed for this architecture. Error code:0x0000098"
Else the computer skips the image mode and goes to Windows.
WDS has this error "The PXE server processed a request from a client of architecture x86x64.  However, there were no boot images installed for this architecture.  PXE clients of this architecture will not be able to complete the boot process successfully.  To resolve this problem, add at least one boot image for this architecture."
If I use a DVD with the boot image the image process goes through without problems.
Things that I tested:
1-Disable PXE support on Distribution points waits for the server to remove the files, reboot and re-enable PXE again.
2-Create a new boot image.
3-Create a new task sequence.
4-Remove support for unknown computers.
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Hello :-)

I have only one DHCP scope with the following settings, it was executed by the previous IT staff:

001.PNG
I need to create a new scope with these settings:

Network: 10.61.10.0
Mask: 255.255.255.0
Gateway: 10.61.10.1
Range: 10.61.10.1 -> 10.61.10.254
Name: Vlan_Wifi

But I receive this error:

002.PNG
What is wrong?? :-(
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The DHCP service failed to see a directory server for authorization.
Windows Server 2008 and Windows Server 2016
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Windows 2008 server migration to Windows standard 2016.  Im having an issue here after a migration to a new 2016 domain controller.  The DC holds all the FSMO roles, is the global catalog server, DHCP, DNS points to it and the client desktop do too.  yet I want to DCPromo to demote the 2008 server but before I do that I wanted to make sure everything is healthy and working.  If I disconnect or power down the 2008 server all the sudden the client stations lose the internal network name and then shows up as "network 3" or 4...etc.. and not the local domain name.

Then I check on the 2016 server and when I go to open AD its giving me errors that no domain controller can be contacted.  

At a command prompt I will run the netdom query fsmo and Ill get the error that  the domain either does not exist or could not be contacted.  

I will run a DCDiag and most tests come back passed except for:

1) Netlogon test - user credentials does not have permission to permission to perform this operation (yet I am sign on at the primary administrator)
2) replication attempt failed between the 2 servers  (error 1256)
3) could not open NTDS service on the 2016 server (error x5, access is denied)
4) unable to connect to NETLOGON share  - error 6, network name cannot be found  (yet this is being shared?)
5) when the 2008 server was down it also showed:

Starting test: LocatorCheck
         Warning: DcGetDcName(GC_SERVER_REQUIRED) call failed, error 1355
         A Global Catalog …
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Im facing very weird issue in my network. Out of the sudden 2 windows 10 PC doesn't have internet, it has valid IP address and can't even ping default gateway or anything else on the network.

But while I was searching around for the fix, I found article where it specified to change MAC address under the network properties to make it work and as soon as I changed the MAC address I got the internet back.

Now could someone, please let me know what could be the issue with original MAC address ?? Or this something ???

I have tried everything I can, update the drivers for network adapter, uninstall and installed the adapter etc

BTW, we are using the meraki MX  84 as my firewall/Default Gateway and I did opened case with them and they were unable to solve it to. One unmanaged switch between PC and Firewall, no AD or DC. PC are on workgroup. NO traffic shaping policy on firewall.

Please share your thoughts..... Thanks !!!
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All expert, I need help to setup ACL for two VLANs, vlan 1 and vlan 20 (guest). DHCP is on vlan 1 that i need vlan 20 to access but block all other traffic. I just want vlan 20 to access Internet connection such as port 80 and 443.  Can you helps me on this? Thank you on advance.
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I have a Draytek 2960 router and two servers; one SBS2011 (192.168.10.5) and one Windows 2016 Essentials (192.168.5.5).
I'm in the process of migrating from SBS2011 to Windows 2016 after which the SBS2011 server will be retired.
During the migration I would like both servers online. The SBS2011 is running DNS and DHCP and the Windows 2016 is just running DNS (DHCP is not installed yet).

I am attempting to configure VLANS on the Draytek, and although all seems sort of OK I'm getting dropouts and poor response when the Windows 2016 server is connected and ports 2,3 and 4 are enabled so I conclude there must be some traffic conflict going on.
My Draytek settings are:
Switch.png
General.png
My intention is that I'm using port 1 for the SBS2011 server and ports 2,3 and 4 for the Windows 2016 (iDRAC, Windows NIC and a single PC on the new domain) so I'm not intending to use VLAN Tagging - I want it all to be physical port based config.
I've achieved a similar configuration on another site but that was using a Draytek 2862N and that worked fine.

Not sure what's going on with this.
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It is a SBS-2011 Server. I will create a new DHCP reservation and set the reservation name to "GSMPC-11 N". Then it looks like when it goes active Windows changes the name to the computername.domain i.e. gsmpc-11.gsmetalinc.com

   Well..... what is the point in even creating a reservation name when Windows changes it to computername.domain automatically? Is there any way to stop it from changing the reservation name?
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Hello,
I have DHCP failover cluster configured (hot standby mode) and its not functioning good.
Sometimes workstations need to restart to pick up IP address.
So,I plan to remove second(standby)dhcp host and remain only one dhcp server
Is this what I need to do?Delete dhcp failover and unauthorize stand by dhcp host?Scope remains?
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Hello Experts,

I want to test DC site failure between 2 sites connected via a leased line. Both sites have 2 dcs each on Win server 2008. Both sites can communicate with each through our leased line.
Both sites have their own DNS and DHCP servers.  

The plan is to unplug both DC on one site and see if those on the other site take over and vice versa. This will simulate a complete DC site failure.

As I understand we will have to move our fsmo's role over to the active dcs when the others are taken down and also DHCP and DNS. If we did have a complete site DC failure on site1 I can I setup a DHCP and DNS in a disabled state in site2 ready to take over in case of an emergency.
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One of our client has a strange issue with migrated DHCP. They are getting BAD_IP address issued by DHCP.
Basically they exported the old DHCP and imported to new DHCP server.
Any help would be appreciated.
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Is it Enough to configure DHCP Snooping without ARP Inspection

I would like to know if it is efficient to configure just DHCP Snooping and do not configure ARP Inspection.
 I thought DHCP snooping is enough to avoid having Rogue DHCP in the Network. So what  else that ARP Inspection adds to the DHCP Snooping ?

Thank you
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I recently split our DHCP addresses between to DHCP servers.  One server has a scope of the first 127 addresses (1-127) of a network, and the other server has the remainder (128-253).  Things appeared to be working well.  Both servers lease addresses in the proper ranges, and I can ping them.  However, on two clients that host web interfaces for various programs, the web interface will not open.  They do open on the localhost.  Are there any ideas about what could be causing this?  I believe both of the clients in question have the proper DNS entries.  However, one client is set to get its address by DHCP and is assigned a reservation.  The other client has a static address.  I have added A and PTR records for both.
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Had to reboot a ESXi 5.5 server.  It decided that it wanted to pull an DHCP ipv4 address.  When trying to set it back to static. it tosses out an error that it cant save it because of iPv6.  We have that disabled.  It can pull a DHCP address no issue.  Never seen this before.  Where do i start?  

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Dear Experts
Installed windows 2016 standard and configured it to function as domain controller, DNS server and DHCP.  It is observed the after promoting the server to AD domain controller the IP of the serer in the primary dns changed to local host I mean pointing to 127.0.0.1, manually changed to the actual IP.
While creating the forward and reverse zone had selected “do not update dynamic updates”
Following are the issues faced
1.      While joining the client system that is windows 10 pro to domain it accepted to join but message shown “preferred dns could not be changed” and then after reboot able to login with domain user. Please let me know where I am going wrong
2.      When the user logon and click on network browse the domain controller can see netlogon directory but does not show the user home directory, please let me know what I have missed.
3.      I made the normal user a member of domain administrator group in the server and then logon to the client system with this user but he does not get admin privileges when click on network to change IP address it prompts for logon and password but it does not allow administrator login to client system nor it does not consider this user as administrator who is actually member of domain admin group  
4.      Before joining the client system to the domain controller is required to create A and PTR records manually and then after join the system to domain
Please help me understand and suggest the steps to resolve the above 1 to 4, this…
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We have be experiencing issues with the DNS servers that are being setup on DHCP clients. We have recently setup and configured Cisco Umbrella. The VA's have been setup and all DHCP scopes have been updated to use the VA's for DNS. All was working well or so it seemed but we started noticing DNS issues. ipconfig sometimes shows the correct DNS servers (the VA's) and sometimes shows the internal DNS server. The DNS servers change in between lease changes. Any advice on troubleshooting would be greatly appreciated.

Regards,
ABBEadmin
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I've setup a Server2016 test environment. Contains a VPN server, NPS Server and a DC. I connect to the VPN fine. Pulls an IP from the defined DHCP scope. I can ping any internal resource, but i cannot navigate to any shares. I've gone as far as completely shutting off the windows firewall on the  server and workstation(Win10) sides, still cannot navigate to a any shared folders on any of the 3 servers. Ive made sure the DNS entries are there. Any ideas as to why i cannot browse to the server by IP?

EX. from an external network connected to the VPN
ping 192.168.17.50 - get 4 responses
ping testdomain (DC server name) - Could not find host testdomain
nslookup 192.168.17.50 - Server: testdomain.test.local
                                           Address:  192.168.17.50
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I installed a domain controller with DHCP. The DHCP configuration was exported from old server and imported to new windows 2012 DC.
The DC NIC was checked for IPV6 and IP4. We are not using IPv6. DG is not enabled for IP v6.
The DHCP is not binding to the ip version 4 nic. The error with event id 10020
" This computer has al least one dynamically assigned ip v6 address. For reliable operation you should only user static ip ver 6 address"
If i uncheck the IP v6 on the NIC then DHCP works.
Any suggestions?
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We have H3C layer 3 switch. I find sometimes staff will bring their laptop / mobile to connect our network through our DHCP on server 2008.

We know their MAC address. Is it possible to deny any network on a particular MAC address on H3C switch?
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Wired users getting 192.168.1.x IP address.  Instead of 10.10.x.x
Not sure what happened.   Not all the users tho.  Any ideas?
ipconfig /renew /release not helping.  
Need some help troubleshooting.
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DHCP shows red arrow, see pic, what does this mean?
dhcp.png
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Get-DhcpServerV4Scope | Where-Object -FilterScript { $_.State -Eq "Inactive" } | Remove-DhcpServerv4Scope -Force -Passthru

1.Kindly provide equivalent NETSH DHCP command as like as PS CMD mentioned above

2. equivalent  power shell command  to run windows 2008 r2 server above command not running 2008 R2
Or

3. My requirement is to delete all inactive DHCP scopes  using netsh or PS(2008 R2) by excluding active one
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A fist time experience for me happened yesterday. My environment is using static IP Addresses for everything; no DHCP. A client was mistakenly assigned the same IP as our primary DNS server and everything in the environment went haywire. There has to be a way to prevent that other than the obvious. Any knowledgeable folks have an idea?
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Cisco 8851 phone not detected into the network. When I plug the phone directly into the switch in registers just fine in call network. Back at my work station. I plug the computer into the corresponding port and it works fine. Plug the phone in, and it get PoE just fine, but cann't see the network. I have cleared port-security on the switch. The phone is set to recieve DHCP just fine. The settings seem to be correct as I can plug the phone directly into the switch and the phone registers in Call Manager just fine. Plug it into the corresponding port back at the work station, and no go.
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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).