DHCP stands for Dynamic Host Configuration Protocol and is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol.

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41 views

ISC DHCP Client keeps asking for address

All of a sudden the network at my University has frozen and we managed to isolate the problem to massive amounts of UDP packets sent on the DHCP ports. On closer inspection, we found that some of the ...
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1answer
57 views

How to make a primary scope and secondary scope on DHCP server?

I am changing network structure and part of that is to change ip from 10.10.111.0 /24 to 172.16.0.0 /16 range. Now I need to have DHCP ready first in 172.16 range. I have two DHCP scope on a single ...
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0answers
39 views

DHCP not working for new pool

I created new dhcp pool(41 pool) in Windows server 2012 called vlan 41,routed with default gateway in router, added interface vlan 41 on core switch 3650, given ip help address as server address. I ...
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1answer
78 views

dnsmasq proxy mode and efi boot

So, I already have DHCP server in my local network. But I want to setup new VMs with network boot (PXE). I've setup dnsmasq in proxyDHCP mode to provide PXE info to booting clients while using other ...
0
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1answer
45 views

Does a Linux DHCP server have IP conflict prevention?

Scenario: We are migrating DHCP off our Cisco gear and onto a Red Hat 6.7 server. I am concerned about clients who will not release and renew for several days. Since the new server will not have any ...
2
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1answer
122 views

DHCP Server with multiple network interfaces and different subnets

I am trying to set up a dhcp server (isc dhcpd on debian 8 (vm inside an esxi environment)) with 4 network interfaces, eth0-3. The dhcp server should serve a different subnet on the interfaces eth1, ...
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2answers
49 views

DHCP Reservation Without Knowing MAC

Is there any possible way to have a DHCP reservation set for a device which I do NOT know the MAC address for? In other words, is there any thing that might just be unique for a certain model of ...
3
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1answer
75 views

How to generate DHCP Decline scenario / packets

I have a dhcp packets sniffer, which needs to log if it sees dhcp decline response coming from client.I need to know the scenario where client can send dhcp decline response to dhcp server. I tried to ...
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0answers
118 views

Force isc-dhcpd to disregard client hostname in ddns updates

I have the following configuration of isc-dhcpd-4.3.1: ignore client-updates; ddns-update-style interim; subnet 192.168.128.0 netmask 255.255.255.0 { use-host-decl-names on; ...
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0answers
12 views

How to allow DHCP between 2 networks using Shorewall?

I have a server with hyper-v and 3 networks: eth0 is virtual, eth1 is physical, eth2 is extranet from ISP. Virtual network has a DHCP running and all virtual machines can reach it fine. But not the ...
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0answers
39 views

Configuring ISC DHCP server to not serve IP's on the local network

Is it possible to have a DHCP server serve subnets for multiple network segments, but not its own local subnet? I have a DHCP server on a subnet 10.x.x.x. It serves approximately 125 subnets on ...
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1answer
48 views

Windows 10 client GPO to favor DHCP server over another one [closed]

We have a cisco RV180W and a Windows server 2012R2, both acting as DHCP servers, the cisco is here to serve IP's if our server is down, but it's been a week since it has taken the lead into DHCP ...
3
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0answers
53 views

How to create DHCP reservations with long hardware address?

DHCP is managed by a Windows 2008r2 server. I want to convert a lease into a reservation so the IP will be fixed. Normally, I create a reservation based on the assigned IP address, and when the lease ...
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0answers
36 views

dhcpd.conf — one-lease-per-client statement having no effect

I have read on this and this man page that the one-lease-per-client true statement in my dhcpd.conf will stop duplicate leases to a single client. However, I am still able to sustain multiple leases ...
1
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0answers
25 views

DHCP: bad configuration fixed-address?

My configuration of DHCP is: dns-update-style interim; default-lease-time 86400; max-lease-time 86400; authoritative; log-facility local7; subnet 192.0.1.0 netmask 255.255.255.0 { pool { option ...
0
votes
1answer
30 views

DHCP reservation with virtualized AD DS

My main purpose is to provide SQL Server Analysis Services (SSAS) on a single physical machine running on say cloud provider premises. Just a remote box that should be accessible worldwide through ...
0
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1answer
117 views

Windows Server with Router in the same network, How to configure?

I have a network with Router that provide DHCP and DNS services to my network. Also, i have a windows server 2008R2 in the same network. I have +100 computers in the network, some must join the ...
0
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2answers
72 views

DHCP in wireless router configuration when connected to VLAN

We are attempting to create a wireless network on top of a wired network. The wireless network is will enable clinicians to use wireless devices (tablets) when seeing patients. The wired network has a ...
4
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1answer
209 views

DHCP: Create a scope within a scope

Before I joined the company I am currently working for, they set up a scope to encompass the 10.2.0.0/18 range of IP addresses (10.2.0.0-10.2.63.254). I was recently tasked with adding reservations ...
0
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1answer
63 views

How to change IP address pool in DHCP scope without affecting existing leased IPs

Within the DHCP, we have the following IP available for distribution Start IP Address 10.1.23.15 End IP Address 10.1.23.199 The current utilization of the IPs is around 50% We are looking to shrink ...
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0answers
19 views

CoreOS docker.service containers can't resolve domains

I have servers PXE booting to CoreOS with persistent state being written to disk. When I start docker containers on the host they work fine. And I have the docker.service set in the cloud-config to ...
2
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0answers
45 views

Creating additional VLANs on Cisco SG200

I would like to create 2 separate VLANs using a Cisco SG200-series smart switch (layer 2) where the devices would not see each other, while being able to connect to the internet. The setup is simple, ...
1
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0answers
23 views

Sonicwall DHCP timeout after AWS VPN tunnel

I have just setup an AWS VPC with a hardware VPN tunnel to our datacenter via a Sonicwall NSA 4600. Everything is working fine with the VPN between Amazon and our datacenter, but the DHCP has stopped ...
0
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1answer
53 views

Multiple IP addresses

I am developing a number of mobile websites (using IIS), and I want to test them using my mobile device which is connected on the same LAN. I would like to access each website via a different local IP ...
0
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1answer
76 views

ISC DHCP Server “Dynamic and static leases present”

i have a problem similar to Fixed and dynamic IPs in ISC DHPD lead to double lease In my DHCP-Log I often receive warnings like Jan 21 10:20:56 dc2 dhcpd: Dynamic and static leases present for ...
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1answer
58 views

Hosting DHCP/PXE server on windows embedded

I am trying to boot a device through pxe, this device is connected to a windows embedded 8 (industry/standard) host pc. It should be possible I think and searches point me in the direction to using ...
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0answers
71 views

Server 2012: How could I create a DHCP scope just for my RRAS PPTP VPN clients?

I am using Windows Server 2012, and the server in question is both the PPTP server and the primary DHCP server. My current setup has a DHCP scope for this location, and anyone remoting in is assigned ...
0
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1answer
90 views

Install DHCP failover on domain controllers vs member servers?

What is the recommendation for installing DHCP failover; domain controllers or member servers? I can't seem to find any recommendations either way. I did find an old question here pertaining to ...
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2answers
61 views

Create smaller subnets from large subnet

My network is 10.10.0.0/16. I would like to break this up into /24s. My environment: I use /etc/hosts with dnsmasq for DNS and isc-dhcp-server for DHCP on an Ubuntu 14.04 server (gateway, router) ...
1
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1answer
53 views

DHCP Server Port-Based Address Allocation on Cisco switch 2960-x

I am trying to configure DHCP Server on a Cisco 2960-X switch to achieve port-based address allocation. I would like the IP address assigned to any device connected to that port to be the same every ...
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1answer
49 views

How to force DHCP server to provide a new IP? [closed]

I am using DHCP option 50 (client is an embedded device running eCos RTOS) to request a specific IP from the DHCP server (DHCP server is a built-in one with Windows 2003 server). First DHCP client ...
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0answers
34 views

dnsmasq dhcp-range for different access points

Is there a way to configure dnsmasq to hand out IPs from different range to different wireless access points? I have a basic Asus router configured as access point (it does no routing and doesn't run ...
3
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0answers
51 views

Cannot renew DHCPV6 lease in SLES12

I need to renew the lease of a certain SLES12 box. The machine is configured to use IPv6 only and so far I have tried the following: From here: dhclient6 -r -v eth0 && rm ...
3
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0answers
63 views

Did I cause this DHCP failure?

I asked this here, it was requested that I move it to this forum instead. I have a question that I need some counsel on concerning DHCP and what may happen in a certain situation. I have a case ...
1
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1answer
24 views

DHCPD configuration by interfaces

I have two interfaces on a machine running Ubuntu 14.04 LTS. Which has two different interfaces namely eth0 and eth1. I need to give IP addresses to the clients by the interfaces. For example, Any ...
0
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1answer
19 views

How to interpret certain aspects of dhcpd logs

I have a DHCP server running on RHEL 6.6. I understand the process (somewhat) involving how the conversation goes from a protocol standpoint to set up a lease. 1 - The DHCPDISCOVER message. 2- The ...
1
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2answers
67 views

Changing DHCP server on Network ramifications?

On our small business network, we've unfortunately got our Cisco RV220 router acting as the DHCP server, but all of our client PCs and Servers are pointing at our Windows Domain Controller running on ...
0
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1answer
66 views

classes declaration inside of subnets in isc dhcp

I would like to use class declarations based on a subnet scope, is that allowed? Or are all classes global scope? here is my dhcp.conf snippet: subnet 10.200.147.0 netmask 255.255.255.224 { ...
7
votes
6answers
457 views

Wisdom of switching from Windows to redundant linux boxes for DHCP servers? [closed]

We've had a few issues with our Windows DHCP server failing. I'm a linux guy by nature, but not a systems guy (I'm a programmer who happens to be running IT for ~800 users), but I'm curious: how crazy ...
1
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0answers
21 views

ip dhcp excluded-address command no work

I want to provide 1.1.1.101 to 1.1.1.126 using dhcp pool. Here is my configuration no ip dhcp use vrf connected ip dhcp excluded-address 1.1.1.1 1.1.1.100 ip dhcp excluded-address 1.1.1.127 1.1.1.254 ...
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2answers
599 views

Hyper-V 2016 Gen2 VM PXE DHCP Timeout (Wireshark DHCP Discover -> Offer -> ???)

I've built a test lab running Windows Server 2016 and SCCM 2016 and I'm having an issue with PXE booting a VM to install an OS via SCCM. Here's the run down on the configuration. At this stage SCCM ...
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votes
1answer
78 views

How do I manually release a DHCP lease on the DHCP server itself?

I have been doing some vm testing. I have created and destroyed a large number of vms on my subnet to test fresh provisioning via puppet. However, it looks like Ubuntu doesn't free a dhcp lease when ...
0
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0answers
110 views

Why do our Windows 2012 R2 DHCP Servers lose reservations?

Windows takes our DHCP reservations, but does not know how to hold-on to the reservations. There is a history of this in Windows 2008 DHCP server, but the closest i could find for Windows 2012 R2 ...
1
vote
2answers
106 views

Dual stack linux router, can't forward IPv6 prefix

I have a small offic here with a few workstations and I would like to implement a small server for stuff like a proxy server, samba etc. This is the topology of said network: +-----+ dynamic ...
0
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0answers
23 views

Ubiquity AP keeps people from connecting sometimes. Happens with a couple other AP's as well

I believe this is ok for server fault, forgive me if not. We have had numerous very cheap AP's and I am trying to purchase a mid tier product now. We had EnGenius ENS 202EXT and a couple home office ...
0
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1answer
37 views

Is there a benefit to assigning a static IP to an instance instead of DHCP

We are creating a Windows AD instance in our AWS VPC and we're wondering if there is any benefit to assigning a static IP to that instance instead of using the default behavior of a subnet which is to ...
0
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1answer
59 views

Create DHCP for 1000 Users

Currently we are running windows server 2003 with static ip for 200 users ,now the organiszation is about to expand so atleast 1000 people will be working, so i needed to create a DHCP for 1000 users. ...
2
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0answers
53 views

DHCP Discovery being Ignored

I'm having some real issues with a DHCP server I've setup. I'm at my wit's end, having found no answer anywhere to this problem of mine. Here's the setup: I have a CentOS server machine, running ...
-1
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1answer
32 views

Priority of dhcp servers

Let say there is a main Server which is assigning ips by dhcp to 50 different LAN ports in network.Now if at some LAN port we connect a small router on the yellow port(so that all other devices come ...
1
vote
2answers
91 views

Window Server 2012 with external DHCP

I have a Cisco router connected to a server with Windows Server 2012 fresh installed on it. What should I do to configure DNS if I leave the DHCP of the Cisco router active?