Dynamic Host Configuration Protocol (DHCP)

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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 ...
4
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1answer
417 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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1answer
13 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
55 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 ...
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1answer
36 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
81 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
246 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
52 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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1answer
1k views

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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4answers
2k 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
809 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
138 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] ...
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1answer
216 views

View DHCP Server Leases

How can I view the dhcpd.leases without having to SSH into the box and view using vi/nano etc. I used to have webadmin set up on another box but that was when I used the GUI to configure dhcp. Now I ...
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2answers
126 views

DHCP options “not user configurable”

I'm using dhcp on both client and server on Linux machine I would like to "force" some dhcp options from the dhcp server to the dhcp client Specifically I'd like the client to set into his lease ...
4
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1answer
793 views

DHCPREQUEST and DHCPACK spam in logs

I've recently noticed that my android phone (droid dna, although the thunderbolt that I had before did the same exact thing) is rapidly requesting dhcp info my dhcp server (isc-dhcp-server on debian ...
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1answer
63 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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1answer
48 views

2 client classes sharing the same subnet range

basically I would like to achieve the followings: using only one subnet different types of user sharing this subnets creating 2 pools accordingly an user class called "l2vpn_user" if matched by MAC ...
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1answer
153 views

Cleanup DHCPD leases as well as DDNS Entries

I have a fairly simple set up on a Debian server I'm running. I currently have isc-dhcp-server installed along with bind9. I set up my zone and my reverse lookup zones and set up dynamic updates, it's ...
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0answers
38 views

How to associate a DHCP pool or subnet with declarations for a class

I have the following working configuration for ISC DHCP server 4.1.1, which hands out fixed addresses to registered clients. Some of those clients are configured for PXE booting (for FAI and SCCM). ...
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1answer
92 views

DHCPv6 Server IP address

I am new to DHCPv6. In dhcpv4 we have Option 54 to retrieve the Server Identifier (ie. Server IP address) in DHCP message. Similarly how to retrieve DHCPv6 Server IPv6 address in DHCPv6 Message. I ...
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1answer
700 views

Cant deploy images with WDS: PXE-E16: No offer received

I am currently playing around with a WDS lab environment on a virtual 2012 R2 server, which is patched to the latest available update-level. This server is running the DHCP server role and has two ...
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1answer
52 views

Are MAC ID passed via DHCP Relay

Do MAC ID pass through dhcp relay? Even if its connected on the WAN from the internet? So if the DHCP Server is on the WAN of the router and connected to a DHCP server on the internet is it passed?
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1answer
53 views

DHCP Relay behind two router

If i have a DHCP Server above two routers and a cleint computer below and the client computer is connected to a router with DHCP Relay, will dhcp pass through those two routers? Here is an example ...
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1answer
48 views

Backup and Restore DHCP

Today our Windows Server 2003 server is running DHCP to serve all clients with IP addresses. We have installed a new Windows Server 2012 R2. Now i want to move the DHCP from the 2003 server to the new ...
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517 views

DHCP offer is unicast but DHCPACK is broadcast

My DHCP server broadcast DHCPACK 0xffffffff . it is not working on layer 3 dhcp relay agent . as it can not forward this broadcast message to my client. can any one help me from exactly the broadcast ...
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4answers
831 views

Resolving IP address conflicts on a LAN

We have our LAN set up with DHCPD providing fixed IP addresses to the systems. However we are facing IP address conflicts if some one connects a laptop and assigns an IP address belonging to another ...
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2answers
293 views

Prefix Delegation and route creation

I'm using the ISC dhcp server version 4.1 for DHCPv6 prefix delegation on a network. When the server allocates a prefix to a client, the server does not create a route for that prefix to the client ...
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2answers
440 views

Windows Server set multiple Gateways and metrics

I would like to configure my DHCP Server (Windows Server 2008 R2) so that it assigns to each host two gateways. The client should use the gateway which is closer (less number of hops). I can do this ...
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115 views

Why need DHCP Relay (Watchguard) inside the Trusted network?

I run a small network that looks like this: { Win 2008 server , desktops , Wifi AP} -> Switch -> Watchguard XTM21 firewall (the Switch is connected to the XTM's Trusted interface ; the XTM ...
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0answers
94 views

One server has multiple IP address leases but just one adapter and no dhcp reservations?

One of our servers' has multiple (10) DHCP Addressleases and I don't know why. The server itself has only one adapter and even if I execute ipconfig /all I only see one IP address defined. Even in the ...
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1answer
508 views

How to find out IP address held by a Windows DHCP client yesterday?

We have a Windows Server 2008 with DHCP server running. I can see the current leases and reservations, is there a way to see the status of yesterday (or at least what IP a particular client had ...
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0answers
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DHCPD does not allow filename option with a colon in it

For some reason, tftpboot does not work with a colon in filename parameter: group { filename "node7:linux/pxelinux.0"; host machine_7a { hardware ethernet 02:01:02:02:01:11; ...
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2answers
57 views

how to get a connection between Windows and Linux without an existing DHCP server

Scenario: In general a ubuntu machine (called server) runs in a network and gets an IP from it. Due to testing, sometimes a windows machine (client) is physical connected to the ubuntu machine ...
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2answers
69 views

How to force the network machines to get the ip from a DHCP server? [closed]

How can I force all the network machines to get the IP from the DHCP server and prevent them from manually editing the network configuration. There are both Linux and Windows machines. The DHCP server ...
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1answer
296 views

VSS DHCP Jet Writer Experiences Errors During Backup with WBADMIN

Summary My standalone physical server is running Server 2012 R2 Foundation. Two separate backup schedules exist, both using Windows Server Backup. I'm getting VSS errors from the DHCP Jet Writer ...
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1answer
771 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
1k views

Setting up DHCP server behind two routers

I have a network configured in the following fashion: |-> Imaging server (192.168.1.42) |-> 192.168.1.100-150 range Internet->Router A-+-> Router ...
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0answers
269 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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2answers
4k views

What are the possible issues in using very short DHCP lease time (< 1min)?

We have a network setup for a demo, which lasts about 15mn. Our DHCP server is configured to assign ~ 100 addresses (max number of simultaneous connections or our AP) ... but since people might come ...
4
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2answers
187 views

How can i locate rogue DHCP servers? [duplicate]

I am investigating some odd behaviour on a sub-net, where host registration doesn’t list some of the IPs that some users report having. Now that I’ve seen evince, i want to passively scan for the ...
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0answers
70 views

Access Denied DHCP Tool

I cannot figure out why this is happening, when opening the DHCP tool on my server, I get the following message. Access Is Denied You do not have access to this DHCP server. To view information ...
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3answers
2k views

Superscope DHCP leases and configuration set up

Hello I wanted to see if someone could help with a network problem I am having. Right now we have a super-scope and scopes of 192.168.50.1 and 192.168.51.1, as of now both are activated but only ...
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1answer
309 views

CentOS: DHCP Server and DHCP relay on same machine

eth0 IP: 192.168.1.100 Alias interface eth0:dhcp IP: 10.10.1.100 dhcpd.conf: authoritative; local-address 10.10.1.100; subnet 10.10.1.0 netmask 255.255.255.0 { range 10.10.1.10 10.10.1.50; ...
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1answer
430 views

isc-dhcp leases file never cleaned

When running isc-dhcp the leases file seems to grow indefinitely (several hundred MB). If I restart the isc-dhcp service, the file shrinks to 1.5MB. How can I have isc-dhcp flush expired records ...
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1answer
145 views

Cannot assign IP address according to an option parameter

I have this DHCP conf file: authoritative; option domain-name "XXX.XXX.XX"; allow bootp; ddns-update-style ad-hoc; class "karpuz-kabugu" { match if (substring (option user-class, 0, 6) = ...
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1answer
977 views

How to run multiple instances of dhcpd or add/remote listen interfaces at runtime?

The same network interfaces interfaces in my laptop (eth1, wifi0, br0) are often connected to different networks (home/work/university network, virtual network with Virtualbox, ad-hoc network with my ...
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1answer
147 views

ISC DHCPD memory leak solutions and or workarounds

Background: I have recently been put in charge of finding the root of and/or fixing a memory leak with an ISC DHCPD (4.2.5-P1) installation on a Debian (Lenny) Unix server. I have been researching ...
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1answer
1k views

DHCP Post-Install configuration wizard hangs

I'm attempting to set up a Windows 2012 Active Directory demo environment on a Hyper-V VM, but when I run the DHCP Post-Install configuration wizard to authorize the DHCP server in AD DS, the wizard ...
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1answer
59 views

Failover DHCP Windows 2012

Is Windows 2012 failover DHCP (hot standby) compatible with Windows 2003? I'm not sure if it's enough to create a Windows 2012 DHCP server and configure failover options.