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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"There are currently no logon servers available to service the logon request" when trying to log on to domain from member server via a RODC in perimeter/dmz network.

I can see SRV records in DNS for the RODC (in _msdcs and primary zone).
The member server is a member of "Allowed RODC Password Replication Group".
I added firewall rules on the RODC for the dynamic port range (49152-65535), TCP and UDP. But it didn't make a difference.
TCP/IPv4 dns settings for member server point to RODC as primary dns server. Assigned IP address is static. There's no dhcp in this dmz network.

nslookup's from member server list the RWDC's when looking for SRV or NS records. It's returning the closest RWDC for the "primary name server" when you look for SRV records.

I tried changing the RegisterSiteSpecificDnsRecordsOnly registry key on the RODC from 1 to 0, and granted write permissions to the RODC for the _msdcs and primary dns zones. I didn't wait long for replication of this change. It didn't work. Should I have waited longer?
Reference : http://blogs.technet.com/instan/archive/2009/03/24/troubleshooting-rodc-s-troubleshooting-rodc-location-in-the-dmz.aspx

I tried each of these changes one at a time. Is it possible a combination of the changes is required?
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I have configured local domain e.g test.co.ke thesame domain is hosted externally with a website. On thesame server i have configured DNS and DHCP. My issue is within the LAN i cannot reach to the website hosted externally instead it loads default IIS page. My Server Runs Windows server 2012.

Kindly assist so the users on the LAN can acess in this case www.test.co.ke

Thanks in Advance
Server 2008 r2 environment. DHCP server is filling up with IP's that have the IP listed as the name, DHCP/BOOTP type's and a 29 character length Unique ID. Im not sure what is causing this, The IP's that do this are not pingable, I can delete the entry's but they will return, Also If I do a reconcile, those IP's are listed. I also have some showing as BAD ADDRESS, they have an 8 character ID and are also not pingable.
esxi1 -dhcp and 3xNICs   vmnic0,vmnic1,vmnic2

on HP 3400cl Switch configured:

Vlan 1 -   DEFAULT                
vlan 10-   ISCSI                        
vlan20-    MS DHCP Server  

TRK1 port 22-24   all are member  VLAN 1,10,20

at the Moment only vmnic0 connected to TRK1 port 24 and work all.
if i Connect  second Network Card( vmnic1) to TRK1 port 23 ,then i loose all Connections , i cant Connect nothing till i plug out vmnic1 .

any help?
Hello.  My Windows Server 2012 installation will not send out DHCP leases.  I have reinstalled the Role/Services.  I have made sure its Authorized.  I have setup a new Scope with 125 addresses.  I have made sure the Server/Scope Options point to the correct Router IP address, the correct DNS addresses and is populated with the right Domain Name.

I'm not sure what to try next.  The event logs from the clients say what you would expect, that they are unable to receive a DHCP address.

What steps should I try?

we have a zebra printer 110 iii plus. we set dhcp and a fix ip address. now we cannot see any network option at the zebra display. and cannot communicate in network. what can we do ?
Hello Experts,
I have a MikroTik CCR1072 router. I would like to use this router as PPPoE Server, DHCP Server, and as bandwidth limiting device in my ISP network. My number of users is 2000+. Now, I use Cisco 7201 and Freeradius server (Open Source), but I would like to exchange Cisco and Freeradius combo for MikroTik CCR1072 and MikroTik User Manager Radius, because I would like to use 10Gbps network. How can I test the PPPoE server load and the bandwidth limit without having to experiment with my live network?

How can I generate a lot of pppoe session with load?

Thank you!!!
DHCP Lease Update

I have inherited a DHCP server that has assigned clients with a 365 day lease.    As I am changing Internal DNS servers and lease information, I need clients to renew their DHCP lease.

Further, I wish to perform this at the OU level or subnet level.
I have an old Dell 6224 switch that was being used in an offsite co-location.  We now no longer use it for that.  I am trying to reset it back to the factory defaults (option 10) and it appears to be working until I go into setup to set up an IP address.  Instead of assigning an IP, I am entering DHCP as instructed.  The switch is not picking up an address from my DHCP server.  If I plug a PC into that cable, it picks up DHCP just fine but if I plug the cable into port 1 of the switch, it gets nothing.  If I plug the PC into the switch, it gets nothing.

  When we have a WIndows server with DHCP server running, you can make it to give out IP addresses to computers on the network.  Say from
  But if your network has, let's say, 350 desktops, 50 network printers and 250 IP phones, somehow you need to make DHCP server give out 650 IP addresses and you wan them to be on the same IP network.
  How do you accomplish that?

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I have DHCP registering DNS names on behalf of the clients and I am seeing those DNS entries in my active directory integrated DNS zones.

Below is a typical scenario I'm seeing a lot of in my DhcpSrvLog File:

30,02/08/18,00:25:59,DNS Update Request,,TESTNAME.acct.local,,,0,6,,,,,,,,,0
31,02/08/18,00:25:59,DNS Update Failed,,TESTNAME.acct.local,,,0,6,,,,,,,,,9004

I look at code 9004 and I see this:

9004 (0x232C)
DNS request not supported by name server.

I am not sure what exactly is going on and any insight is much appreciated.

Thank you
Best way to provide a users read only access for below
AD Groups
DNS entries
DHCP scopes
Hi. On my dns server i will build several IPv6 registries for clients that did not already exist. Of course I do not have IPv6 scopes on DHCP. Please help me thanks for you.
Have an issue with one server that says  "no log on servers ,specified domain cannot be found or contacted" after being online for 12 hours.. A simple reboot of the server fixes the problem but rebooting everyday is no a solution. Reading an article says there could be problems with with DNS, everything seems fine to me but i could be mistaken . I have a single domain controller, that runs dns, DHCP and A/D. I ran DCdiag and came back with errors. I have attached a dc log file. Started going through event logs and noticed  domain controller that has netlogon error that occur every few hours and not really sure how to fix it..  I am attaching the error  in log file
Clients continuously Server 2012 DHCP get new ips from server.  I can release and renew and get a new ip every time.  I am also not able to configure reservations for the same machines.  I have considered the possibility of a DHCP consumption attack but not sure that's the case.  

Any ideas would be greatly appreciated!
HI, I need help how to approach domain migration from one domain.com to domain.local.

I have the current infrastructure set up in one domain.com but because there are a lot of outdated records that was never removed from the domain controller I would like to start fresh and create new domain domain.local create new users and reconnet all devices from one domain to another. Obviously, there will be a time when new devices will exist next to new one so I will need to build some trust. How I can approach that task. Can I create second domain controllers on the same network subnet and just one-day flip switch for DHCP or setting up a new domain in the new subnet will be a better idea?
We have an ATT Arris 5268AC gateway that had dynamic IP internet service and was passing traffic flawlessly to a Sonicwall TZ400.  Last night traffic stopped being passed.  When connected directly to the gateway with an independent client (desktop) we can get WAN access and see our public IP no issues.  ATT convinced us to buy a block of static IPs to fix the problem but no luck.  I need to 5267AC to pass all WAN traffic to the TZ400 as no user behind the firewall have any WAN access at the moment.  We are on our failover comcast circuit at the moment but need to resolve this.  The Sonciwall provides DHCP and inherits DNS from the WAN.
I have a windows 2012 server, running DHCP service, with MAC whitelisting (the "Allow" list)

whitelist functions correctly, unauthorized MAC are ignored

logging is fine I can see it in windows\system32\dhcp,

DHCP requests from MAC not on whitelist, they get ignored, but Im *not* seeing a log entry documenting these unauthorized MAC address dhcp requests.

is there some switch/setting to log these?
Fresh install server 2008 r2, created password, set static ip to nic, {broadband router, lan dhcp diabled, firewall off, ip range set to 1 ip, nic ip settings ip, subnet mask, gateway (routers ip), dns set to dc ip - or left blank, IPV6 unchecked, computer name changed to : Server,  System restart, Updates set to auto download, remote desktop enabled (more secure), add roles checked active directory services, popup to install .net so ok then next does the role install, restart after then run dcpromo from start menu search, create forest name FQDN: JRSS.NET (no errors after checking) function level 2008 r2, database, logfile, SYSVOL all left at default, set restore admin password, nic dns 1 now set to so changed it to, dns opened and forwarders set to,,,, interface set to only listed ip, dhcp role installed, dns entered, clear that and enter then verify and all is fine, next, ipv4 list, next scope add, name home, def, home, start ip end ip, gateway (optional) (routers ip), next no WINS, disabled IPV6, restart and device ie router, dc. next i create a PROFILES partition with Users Folder created and shared with setting set as everyone with full access, share name \\SERVER\Users, next i create an OU: Home Users and Guest Users, in Users I Copy Administrator …
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I had this question after viewing Cisco ASA 5505 and Microsoft DHCP superscope.

Hello everyone, i am new to this forum and i have a question similar to this one.

i have a Microsoft Sever 2008 R2 which is the DNS and DHCP . IP Scope is -
its sonnected to a switch and then to an ASA5505 that goes outside to the internet. its all working and fine. but then the users using WIFI and cable to connect and the IP range is all but used up so i want to extend. i created a supercope in microsoft sever 2008 r2 and its range is - also on the ASA i created an interface name inside1 and assinged it an ip of /24

how can i get this to work using the ASA?

Hi - i need help setting up a guest wireless network on a different subnet from the work wireless network.
We have 2 D Link AP's that have the ability to have up to 4 SSID's with different VLAN's, DHCP is coming off a Windows 2008 server and all are connected to a Netgear switch that has VLAN capability.
Please can someone help me with this setup - is it even possible to have a separate guest subnet with this setup?
I'm helping a small school with limited resources set up some Cisco APs in their network. We want to keep the wireless devices outside of our internal network via a separate VLAN. I've had difficulty setting up this environment and could use some help.

Some older Cisco 720i APs A handful of old Cisco Catalyst 2960 Switches An APU2C4 appliance running pfSense acting as our Router/Firewall

What I tried:
I don't have much experience with the Cisco CLI, so I've been trying to set up as much as possible on the APs themselves via their web interface. APs have VLANs set up with an open SSID. I tried associating the ports these APs are connected to on the Catalyst 2960 switches with the VLAN we want to use. Also tried to use DHCP Relay (or "IP Helpers" in Cisco-speak) on the pfSense appliance and setup IP helpers on the APs, but I really have no idea what I'm doing at that point.

Any advice on how to actually get this done? Commands and step by step guidance would be greatly appreciated.
We have observed that from time to time when a scope is disabled on server A, other scopes on server B are disabled. I guess because scopes go through a disable-enable operation, however some scopes are not reactivated.

How do we tackle this ? Any way to prevent this from happening ? Is it a known bug ? Is a hotfix available ? Anyone else has experienced this issue ?

i.ve scom 2016 and need to specify some service that i need to show using the visio to make dashboard. so if i need to check health of the DNS service in my 3 domains how can i do that and shall i choose. also if  i need to check the status of my DHCP subnets can i do that?
i'm using visio 2013 and the scom addin installed but it's for system centre 2012 does it make any effect?
also if i need to just click on the service from the visio should it gives me the status of this object only?
I had this question after viewing UUID for OEM Bios no embedded Ethernet mac address , after vista II OS , is it protecting or abnormal ?.


This topic case can be closed as:

UUID is modifiable feature as many as no limited with motherboard changed .  Vista II DUID with IPv6 can not be changed followed rules of NIC and IANA.

Question recreated as:
Vista II DUID ahead of dhcpv6 valid from my ISP Apr. 2014 , broadcasting to the networks, taken away authentication  and rollback me as its client of "server" .  ISP prolonging for treating this since 2012 with dhcpv4 only to later it having had dhpv6 .  The Modem.ISP only can release an fe80:: layer IPv6 to the gateway and as dns.ipv6 by the ipcfg /all command reported.

Whose DHCPv6 broadcasting DUID embedded OEM motherboard.mac replaced off and lost ?
ipcfg modem dns
Gateway assigned fe80:: local layer IPv6 from the stranger upper device , unauthenticated "Server"  device / platform?
modem gateway IPv6 fe80::

Your writing  back are expected on  how to modify this and calculate the mass caused inside the complexity .  Let have a valid IPv6 directly from ISP.   ISP routering service not relied these years by 1996 , because the poor firewall and account Username duplicated in high/low case. While the local wireless …






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).