Questions tagged [dhcp]
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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Replacing router's DHCP server with Windows Server DHCP
I have a D-Link / TP-Link router which is working as DHCP server leasing IP address to IP phones and workstations. I need to replace this with Windows Server 2012 without interrupting the operation of ...
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Can the firewall prevent the DHCP to give an address, how to fix this?
I am not getting an IP in the subnet 10.0.0.0/24 where the DHCP is working and should serve an IP, I am getting instead only an IP in the subnet 169.254.0.0/16(link local address) that is probably ...
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Windows Server DHCP vs. Cisco DHCP
One of our contractors just tried telling my boss that we should be using our Cisco ASA to serve DHCP instead of our DC... Is there any merit to this? Or is he just, once again, blowing smoke.
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Changing DHCP Scope brought down the Internet connection
My school DHCP server(Win2008) runs out of IPs so I expanded the scope:
original: 10.20.1.0 to 10.20.2.255
new: 10.20.1.0 to 10.20.3.255
But as soon as I finished it, all my workstations could not ...
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How can you designate a DHCP server?
I have a client that has a DHCP server for voice and a DHCP server for data. They have both voice and data on the same VLAN (I know, not ideal). Some of the computers are getting DHCP addresses from ...
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How to treat a request in DHCP from an unknown host?
I have quite few dhcp request from unlocated hosts, like:
dhcpd: DHCPDISCOVER from 00:25:90:54:91:b7 via eth0: network eth0: no free leases
Whats the best way to locate the host querying the dhcp?
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Internet-facing DHCP server
I have a hub, with some computers plugged into it, and a cable modem. All of the computers except one have statically-configured addresses. The remaining computer runs a DHCP client, to get an IP ...
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Unable to get the ip address of linux PC's(Ubuntu desktop)
We are unable to get the Ip address, I have checked DHCP server we have Ip address available, we can get the Ip address I connect windows system.
Please help me to resolve the issue... Thank you in ...
user57216
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windows 2003 server DHCP and DNS configration
i have my notebook in Windows 2003 server domain where server IP is: 192.168.1.14
to access all the features off domain like folder redirection / printer sharing
i need to change my laptop DNS to ...
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Some XP clients intermittently getting wrong IP for STATIC IP Server
We have a server with a static IP, let's say x.x.2.5. We have several WinXP (but not all) that will occasionally resolve the hostname to x.x.1.59 (x.x.1.x is the local subnet).
The DHCP range in the ...
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DHCP IP address with a client specified DNS server? Is this against spec?
I have some embedded network devices that allow me to specify whether or not they use DHCP. Unfortunately, we have some clients that have less than stellar DNS servers in their networks and have ...
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WinXP using old DNS server IP even though changed in DHCP and on the box
We recently decommissioned an old Win2K3 DNS/DC server and replaced it with a new fancy Win2K8 DNS/DC server. Due to timing we didn't give the new DNS server the same IP address but added a new one.
...
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DHCP renewal can't go through because DHCP server is down
To my experience, if a DHCP client tries to renew its lease, but the DHCP server is down, and after the lease time is over, there are two possible scenarios:
The client keeps the IP
The client goes ...
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DHCP renew fail - internet drops every 2 hours
Every 2nd hour all workstations lose internet connection for 10 seconds. The ISP tech support seems to be reluctant to resolve the issue so I am trying to fix it myself. Here is a diagram of our ...
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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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Supersede default route
I have two network interfaces eth1 and wlan0. I would prefer all outbound traffic to go through eth1 before wlan0, but if eth1 is not up, and then wlan0 should handle the traffic.
Both interfaces get ...
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DHCP server - No IP for computers out of the domain
I would like to know if there is a way to deny leasing an IP address through my MS DHCP server to computers which are not registered in my domain.
Thanks!
user238856
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Don't want isc-dhcp to ever reallocate reserved ip even if hosts is down
I've allocated ip's to some systems through dhcp and then made entries in dhcpd.conf for reservation so that these ip's are not allocated to other macs. But when the system with reserved ip is offline ...
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DHCP over PXE fails, but in the OS it works - with configured (R)STP
I'm trying to PXE-boot desktop-machines to install a new OS over the network, but it isn't picking up an IP address via DHCP during boot. When an OS is already booted on the machine, it is working ...
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Avoid connect 2nd DHCPs on 1 LAN [closed]
I have a LAN network using Draytek 2910 with DHCP. The network goes through 20 different rooms. At first everything is working good. Suddendly the network keep losing IP addresses every 30 t0 60 ...
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Peer domain not authenticating users
I have a forest with two DCs, one of which was added as a peer to the original DC.
One DC is running Windows Server 2008 and the other is running Windows Server 2008 R2. I can see on both servers ...
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How to query specific DHCP server
is there a way how to query a specific DHCP server for an IP address? Something similar to
dig @_IP_ADDRESS_ _server_name
dig @8.8.8.8 apple.com
Thanks
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Domain rebuild from scratch
I have to rebuild the entire domain of a company I just started with. It currently runs SBS2003 but it is "FUBAR". MMC is not working, I cant use the BPA on it. I cant get adprep to work to do the ...
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How to prevent MAC spoofing
I have configured a DHCP server on Ubuntu and a fixed IP address for a specific mac, like this:
host client1 {
hardware ethernet E0:69:95:73:2C:66;
fixed-address 192.168.0.10;
}
If anyone ...
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2 networks with a layer 2 bridge that shouldn't be there.
I have 2 separate networks that I manage. They have a router between and layer 3 connection is working fine. Last week my DHCP servers started handing out IPs across the networks, looking around I ...
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DNS and DHCP addresses aren't matching up
Server 2008 R2 DNS and DHCP server (same server).
For some reason over the last few months I've noticed that many of my DNS entries are incorrect. I'll try to remote into a computer via hostname, ...
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DHCP Relay setup in ubuntu server
I have a network appliance (QNO) that works as traffic load balancer and dhcp server. I would like to add a linux server in between the network appliance and the client computers. The linux server ...
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Ubuntu based VPN server behind NAT router?
I have a small intranet- and file-server inside our company, which can only be reached from inside our own network.
I'd like to be able to reach the intranet and files on the server from outside the ...
maartenn88
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DHCP giving errors on static IP
I believe it's the dhcp, can't seem to figure out. The office has about 35 computers and most of them dynamically set-up IPs. A few computers cannot access the Internet unless you manually input the ...
jav
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Is router DHCP server reliable for remote system?
I'm setting up a small unattended network containing one server and several node machines that communicate with that server. Is setting up a reserved entry on the network router's DHCP server for each ...
Nicholas
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Configuring wireless network with multiple AP's
I have my primary router running ubuntu, which has been working fine for my basically very tiny large-scale setup (if that makes any sense at all). I got a handful of extra soho routers which I ...
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DHCP Pools on Ubuntu DHCP server not working properly
Mac addresses ending with "55:a3" and "56:2a" are also ending up in last pool
123 match if binary-to-ascii(16,8,":",substring(hardware, 5, 6)) = "55:a3"; ...
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Is it possible to force the DHCP server to assign a different IP address each time the address is renewed?
I need to detect IP address renewals in my C++ Linux application and check if the new address is different from the old one. I have access to a router running OpenWrt. I can change the lease time, but ...
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Server 2019 AD Subnet "Best Practice"
While assigning subnets to a single server on a single site, I am not sure which way to properly create the subnet.
Example:
If I have a single DHCP Scope of 10.190.8.0/21 (addresses 10.190.8.1 to 10....
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I've Encountered A Strange Network Interface. Is This A Standard Practice?
I am currently developing ONVIF software, and one of my test cameras has presented me with a rather odd network interface.
The camera in question is an AXIS M3045-WV. It's a fairly low-cost (for AXIS)...
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With static IP on Hyper-V ping to VM fails
I have configured a VM on Hyper-v. With the VM network adapter configured to receive DHCP the ping works fine but when I set it to static IP address ping from host to VM always returns time out .I am ...
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Weird routing behavior between 2 Subnets
I have two Subnets and the Routing works like this:
Client A can Ping (ICMP) Client B
Client B can't Ping (ICMP) Client A
There are no Routes manually configured in the Access Point (Google Wifi ...
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Migrating DHCP - keeping existing assignments
I've inherited a fairly messy situation with a production network. DHCP is being handed out by a proprietary vendor device, and we need to retire this device as soon as possible.
We'll be moving to ...
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WDS Server - How does DHCP scope option 67 work?
What is the purpose of DHCP option 67? I thought the PXE client will look for a boot.wim file. Does the boot file located in 67 (like boot\x64\wdsnbp.com) go out and search for the boot.wim?
What ...
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DHCP Windows Server can create multiple scope same subnet?
I have one server DHCP Windows Server 2012 R2. Can I create the scopes :
Scope A : 10.10.10.11 - 10.10.10.30
Scope B : 10.10.10.31 - 10.10.10.55
Scope C : 10.10.10.56 - 10.10.10.105
Scope D : ...
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powershell: Remove-DhcpServerv4Lease does not remove existing leases
I want to delete all DHCP leases and reservation from server WSKELLER. From the documentation I seem to understand that this would be accomplished with:
Get-DhcpServerv4Scope -ComputerName WSKELLER | ...
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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 ...
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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. ...
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Auto DHCP IP Phones to a different subnet
I'm standing up a 3CX PBX system in my office and would like to set my DHCP to assign IP phones a 10.10.8.x address, while giving everything else a 10.10.0.x address (our current net).
What would be ...
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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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Powershell where-object speed improvement
I want to get a list of my DHCP reservations from my DHCP Server running Windows Server 2012R2. The list should contain the IP, MAC, name, description and the lease status of the reservation (just to ...
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How to configure PXE/Tftp in dhcp.conf on vmware Fusion 7 Pro with static reservations
I'm senior devops engineer with a deployment system to ship a couple thousand linux machines a week. I'm using vmware fusion 7 pro to do this, and I'm having a little trouble with pxe booting.
I ran ...
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iptables on Linux router does not forward DHCP between two LANs
I have an internal network as follows:
A Linux system that serves as router, using iptables, with two
network cards
A client machine
A DHCP Server
The Router's eth1 is on the same LAN as the ...
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Split a Scope Linux<=>Windows
Is it possible to create a DHCP Failover Cluster between a Linux(Ubuntu) based server and a Windows Server 2012R2 based server. My idea was to include a new data into the dhcp.conf data to exclude a ...
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incorrent subnet/mask combination
For a network interface, I have defined a range of addresses for DHCP.
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 08:00:27:5a:3e:be ...
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