Dynamic Host Configuration Protocol (DHCP)

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How could I fix “No subnet declaration for restart (0.0.0.0)”?

I have a DHCP service installed on my distribution, Backtrack 5 R2 (ubuntu 10.04) and it was working fine, but when I began to configure DNS it suddenly stoped working, how can I make it work again?? ...
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3answers
1k views

Secondary DHCP server won't start on Centos 6.2

I'm trying to create a backup DHCP server. Server times are in sync. Primary server starts fine. Secondary server won't start. Error from /var/log/messages is: Sep 15 14:47:45 stream dhcpd: ...
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19 views

How to disable or turn off DHCPv6 on Cisco 3939B router?

I am trying to set up a Windows Server 2012 R2 Essentials server properly. I would assume it could also apply to non-Essentials also. i.e. Standard. DHCP for BOTH IPv4 and IPv6 MUST be turned off or ...
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Sharing an internet connection with 3rd party DHCP server on Windows (other than default ICS) [on hold]

I am writing a script that would install software packages on 150+ devices that runs Open-wrt Linux. I will be running software installation scripts on 8 devices at a time via ssh. Since I do not have ...
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1answer
22 views

Error when configuring a failover DHCP: “The following scopes already exist on the partner server”

Server 2012 R2 I get that error message when clicking next in the Failover Wizard after specifying the partner server, but I don't understand it. In trying to research how to setup a failover DHCP ...
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1answer
3k views

Windows Server DHCP import/export scopes using netsh.exe

We have Windows Server 2008R2 as domain controller with DHCP Server functionality. Task was to make reserve server on remote site in case of failure of main one. The reserve one will be running ...
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2answers
33 views

Can ping server one from client 1, but can't ping client 1 from server

I set up a router on my linux machine as described here. Now I can ping the server/router from my windows client. I can also ping my linux client from my windows client. But I can not ping the windows ...
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3answers
1k views

Fixed dhcp host to automatically expire any lease

I have the following situation: Multiple offices with multiple firewall/dhcp servers. Every time the IT team of some office plugs a new network printer i need to create a fixed-address entry, and ...
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24 views

Server 2008R2 DHCP Server not responding to Windows Clients

I have a Windows 2008R2 Server running DHCP Server, configured with a custom dll to assign IP addresses based on circuit IDs. Linux clients and pxe boots (using ipxe) recieve IP addresses from the ...
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4answers
2k views

How to configure TFTPD32 to ignore non PXE DHCP requests?

I want to give our Windows guy a way of easily PXE booting machines for deployment by plugging his laptop into one of our site networks. I've set up a TFTPD32 configuration which does just that, and ...
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1answer
23 views

DHCP post-install configuration error

Server 2012 R2 I moved my DHCP operation out of my Cisco router and into the server. In this case I used the domain server as I have a small system. DHCP seems to be working fine. However, Server ...
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2answers
208 views

How to “segregate” non-domain DHCP clients with Windows 2012 R2?

I search a way to prevent network access to devices not belonging to our corporate Active Directory domain. Some people connect their personnal laptops to our corporate network, and some of them ...
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79 views

Different subnet mask on router and DHCP server

ran into something funny today and am still scratching my head on why this happened. I was trying to increase the number of ip addresses available from my dhcp server by changing the netmask from /24 ...
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1answer
16 views

Obtaining the running config for dhcpd

Is it possible to obtain the current running config for dhcpd? I inadvertently wiped dhcpd.conf but have not yet restarted the service. It is currently assigning the correct IPs to my test ...
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1answer
53 views

Workstations connected to SBS 2011 can not connect to “http://connect/” and are getting frequently disconnected or kicked off of the shared drives

Small Office, there are 7 computers and a server running SBS 2011. 2 workstations are not currently bound to the server, because after recently reinstalling windows 7 on them, it was discovered that ...
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27 views

Polycom phone not requesting DHCP offer

My Polycom IP550 phone is not requesting the DHCP address that my windows 2012 server offered it. I have done a wireshark capture on a mirrored port on our switch and you can see that the phone is ...
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1answer
461 views

Windows Server 2012 DHCP and OSX Devices

I've recently put together a small office network (around 20 devices) with an attached machine running Windows Server 2012. Our gateway router provided by our ISP was pretty useless and started ...
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1answer
25 views

DHCP attribution without DHCP client

j'ai un serveur DHCP qui attribue des IP selon les adresses MAC des clients. J'ai un client qui n'a pas de client DHCP installé (pas que je sache). I have a DHCP server (on linux) which gives IP ...
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2answers
56 views

How to block DHCP traffic using iptables

First let me describe my environment: There is a VM (CentOS) acting as a gateway The gateway VM has to NICs, eth0 connects to public network, eth1 connects to private network eth0 get IP from public ...
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Windows DHCP server not discarding PTR records when an address is leased

Got the following setup regarding DHCP & DNS: Windows Server 2003 doing DHCP Windows DNS (different server)authoritative for the forward zone BIND DNS (on a UNIX server) authoritative for the ...
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1answer
67 views

Multi Vlans with one DHCP server [closed]

We have multiple vlans configured on Cisco 4506, two of them with dhcp enabled to serve living area inside our company and wireless. I installed a new DHCP on windows server 2008 r2 and planning to ...
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1answer
187 views

XenServer 6.2 DHCP Setup

I have a XenServer 6.2 running on a dedicated OVH Server. For this dedicated server I have 2 additional IP blocks. Whenever I setup a new VM (mostly CentOS 6.6) i have to skip the network ...
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1answer
48 views

DHCP with fixed IP hosts (Ubuntu)

I'm managing an office system that assigns IPs based on the MAC address. The fixed hosts are added in a dhcpd-hosts.conf file which is included in dhcpd.conf. There are some PCs that are not in the ...
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2answers
89 views

DHCP server on subinterfaces

I have created two subinterfaces on eth0 : eth0:0 with IP 192.168.10.1/24 eth0:1 with IP 192.168.11.1/24 Configured /etc/dhcp/dhcpd.conf like that: option domain-name-server 194.204.159.1; ...
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Windows 2012 DHCP ignores priority among server / range / class-policy / reservation options?

I am observing that the priority of DHCP settings in Windows 2012 DHCP server server options range options class options reservation options among which the ones listed later always override ...
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DHCP Config for Server 2012 R2

This question may have been covered before, but it is rather complex and haven't found a similar post, so please be kind! I think my issue is rather unique, so I'll try to explain as best I can. I'm ...
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1answer
34 views

How to use Server2012 as DHCP and on the same time Ubuntu Server as Gateway for the client Machines? [closed]

I want to use Windows Server 2012 R2 as a DHCP for the client computers with Ubuntu server acting as gateway to the internet. I am using VMWare WorkStation. Both machines are installed on it. Windows ...
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1answer
487 views

configure a dhcp server to serve two different scope on the same subnet with multiple interfaces

Ok, so here I am with a pretty complicated problem on a Debian Wheezy server I have three interfaces : eth0, eth1 and wlan0 on a single server, eth0 will act as a gateway for eth1 and wlan0, I have a ...
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1answer
67 views

Why are DHCP leases not included in DHCP Log?

Running Windows Server 2008r2. DHCP Logging is enabled (Server Manager, Roles, DHCP Server, , IPv4, Properties, General, Enable DHCP Audit Logging). In the DHCP event log (Event Viewer, Custom ...
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1answer
48 views

Is it possible to bring down a network with DHCP discover?

When a DHCP server receives a DHCP discover message it broadcasts the offer across the entire network. If a malicious machine joined a network and somehow began spamming DHCP discover messages, would ...
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66 views

calculate reserved ip address based on mac address

Is it possible to calculate ip address based on mac address for isc-dhcp server? For example: 'aa:aa:aa:aa:aa:x' => '10.10.10.x' I have following in dhcpd.conf: subnet 10.10.10.0 netmask ...
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127 views

2008R2 DHCP Server Becomes Unresponsive

At the end of 2013, our single Windows Server 2008R2 DHCP server started becoming unresponsive once every week or so. The server itself was up, but the DHCP server was unresponsive. Attempts to ...
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700 views

SCCM 2012 R2 OSD pxe-32 : tftp open timeout

I have SCCM 2012 R2 standalone primary site on windows server 2012 and i have Cisco dhcp server i configured the distribution point for pxe boot to work with osd i added boot images and configured ...
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3answers
1k views

Why does a DHCP server need a static IP address?

I'm experimenting various network setups using VMs. When I setup the DHCP role on Windows Server, it requires a static IP. I am having trouble understanding why this is necessary from a technical ...
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73 views

How to configure DHCPD server to bind static IPv6 address by DUID?

how can i configure the server to make static record DUID - IPv6 ? For example i have such DHCPv6 request: Client Identifier Option: Client Identifier (1) Length: 7 Value: 31303030303133 ...
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CentOS DHCP server supporting multiple subnets on a single NIC

I understand that what I am asking has been asked a million times already. I think I have read just about every post I can find on the subject yet I still cannot get this to work. I have a DHCP ...
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1answer
37 views

1-dhcp server for 2 separate network

Debian Server Setup (wheezy) 1 - eth0 - Connected to INTERNET 1 - eth1 - LAN 1 (Network 1 : 192.168.100.0/24) 1 - wlan0 - Access Point (Network 2 : 192.168.200.0/24) /etc/network/interfaces auto ...
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14 views

Change DHCP on server 2k3

Ok I am trying to mess with our dhcp settings on our domain server because at this point we kinda have competing dhcp servers between the router and the server. (Long predates me and I have finally ...
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54 views

dhcp relay with failover to local service

I'd like to set up a dhcp server which normally relays to a central site, but has a pool of addresses to hand out if the link to the central site goes down. I'm using isc dhcp server on Debian, but ...
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2answers
649 views

dhcpd pool exhaustion - What's the result?

I have a DHCP server that serves leases to several houndred, maybe up to a thousand, different clients on an average day. The pool consists of 242 IPs, and due to the highly dynamic nature of the ...
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1answer
18 views

DHCP server with 2 NICd

I have windows 2012 r2 x64 standard server. That server has 2 NIC nic1 gather IP from LAN1 nic2 - here i need run dhcp for LAN2 (black network) This server will have firewall which will be use ...
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2answers
95 views

Duplicate MAC address, can be blocked?

Let's say we have DHCP server and provided MAC filtering system. Can we blocked the next spoofed MAC address? The next device will not be leased any IP address. Or normally it is already blocked by ...
3
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1answer
215 views

GPO to Configure DHCP Options

Our environment has approximately 15 Domain Controllers that also provide DHCP functionality to their networks. We have discovered several to have incorrect DNS settings. Their are providing incorrect ...
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1answer
94 views

Multiple DNS mappings for a host via DDNS

I have a network in which DNS is automatically updated with a record for hosts when they get an address via DHCP (isc-dhcp-server & Bind configured with DDNS updates). The DHCP server is ...
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5answers
3k views

Querying a DHCP server in C#

I have a really large network. Class A network and due to security reasons broadcast and any other PING has been blocked. I want to get all the PC IP that are alive. Is there any way to query DHCP ...
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1answer
259 views

Parsing the results returned via DHCPd's OMAPI interface

I'm experimenting with OMAPI as a means of giving our support staff additional insight into the state of a subscriber's service. Anyone who's ever played with OMAPI knows two things: The ...
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2answers
107 views

SBS2011E + WS2012 + split-scope DHCP + site-to-site hardware VPN

Bit of a newb when it comes to this but I'm giving it a go and, so far, things work but I hope I'm doing it in a correct manner and a couple of little hiccups... HQ has a SBS2011E DC (DC1) that ...
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4answers
3k views

Windows DHCP Server - get notification when a non-AD joined device gets an IP address

SCENARIO To simplify this down to it's easiest example: I have a Windows 2008 R2 standard DC with the DHCP server role. It hands out IPs via various IPv4 scopes, no problem there. WHAT I'D LIKE I ...
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1answer
985 views

When does ISC dhcpd expire leases

When exactly does ISC dhcpd forget a lease that is not explicitly freed by the client? Context: I am running an installation with many small pools (3 address) and it does not seem to cope well when ...
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1answer
275 views

set unlimited lease duration throuth CMD

On Windows Server 2008 (R2, 32-Bit, I found the following way to set the lease duration for, say, 3600 Seconds (1 Hour). netsh dhcp server scope 10.0.0.0 set optionvalue 51 DWORD 3600 [→ source] ...