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.
2,152 questions
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Ubuntu 22 not getting ip from dhcp on boot
We have a network with ISC running and serious number of VMs running in the same network. While this specific Ubuntu is booting it does not get IP from DHCP. According to DHCP logs, ISC is giving the ...
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Is it possible to do prefix delegation per shared-network using ISC DHCP?
I would like to use ISC DHCP to provide prefix delegation per RFC 3633 for a small ISP's customer network. While reading through ISC's documentation for dhcpd.conf(https://kb.isc.org/v1/docs/isc-dhcp-...
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PXE does not make dhcp request
I was experimenting with DRBL. In order to do it, I've created two virtual machine in VMWare Workstation.
The two virtual machines are connected together by a virtual private network, host only, with ...
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How to access IP and port configuration of the tablet running Linuxmint with "hostapd + DHCP"
My task: Configure and run Access Point (AP) on the tablet (x86) with Linuxmint with access from devices connected to the created AP.
Background as additional information (but this is not the topic of ...
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External IP answering DHCP requests
Testing the DHCP with "DHCP Find Version 1.2" and leaving it open for some time, it shows DHCP offers from an external / public IP. How is this even possible? We use a network within 192.168....
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Windows Server gets IP address via DHCP for too long
I don't know if I specified the correct title, but the point is that Windows Server tries to get an IP address within 2-3 seconds. But at the moment when the lease renewal occurs, the server has no IP ...
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ebtables input and output rules to allow only dhcp packets is not working
I have a topology like below:
....enp0s9.256...
enp0s9.... .... br0 (1.1.1.1/24) (dhcp server)
....enp0s9.257...
enp0s9.256 and enp0s9.257 are vlan interfaces.
br0 ...
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DHCP relay not sending responses to client from S2S VPN
I have a DHCP server that is connected to a router(R1) which has a s2s VPN connection (interface tun0) with another router(R2) where the DHCP client is on, I set up DHCP relay on R2 using isc-dhcp-...
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AlmaLinux 8.10 VPS hostname keeps getting overwritten, probably by NetworkManager
On AlmaLinux 8.10 ....
I am trying for over 12 hours to change hostname permanently so it does not change back when I reboot. Very frustrating.
With most servers it works with hostnamectl set-hostname ...
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Radius and 802.1x windows networking
I am curious how this scenario at AD connected Windows laptop works:
before login to domain account for the first time the computer needs to be connected to Wifi
using WPA3-Enterprise the user enters ...
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windows server DHCP multiple scope relay trouble
I want to create 14 subnets (10.10.10.0/23, 10.10.20.0/23, 10.10.30.0/23, etc)
I have a DHCP server running on a 15. subnet, 10.100.10.0/24 with the address of 10.100.10.100.
The problem that arises ...
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DNS server not being used for resolution on an AWS VPC network
I have a VPC in AWS with multiple public and private subnets in different availability zones.
I want to host my own DNS on this network to use single label hostnames. For example, I want to use ...
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Dhcp range with fixed Ips
Here I have a DHCP server with some IPs with fixed IPs that are in the range 192.168.1.91-254.
And for the leases only the range 192.168.1.11-90.
But I want to make the lease range bigger can I use ...
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DHCP assigned addresses following devices/users and routing
We have three campuses and two data centers.
We are considering assigning IP addresses to devices based on the department, so people can move between campuses and those campuses connect to ...
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Can a docker container get a hostname from an existing central DHCP server?
Given: We have a service that is currently run on a VM with a MAC address of 4E-3C-FC-EF-C5-45. Our DHCP server assigns it a name of "pixie1". The IP address doesn't matter because ...
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Windows Server 2022 Hyper-V DHCP Lease code 83
I need help with Hyper-v Windows Server 2022.
Recently Spinned up a new Cluster on Win 2022 and I am facing Network challenges with the VMs not seeing the Network. But only the ones deployed without ...
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Why dhcpcd deletes routes?
I have servers on Hetzner with Ubuntu 24.04 with private network only.
Every 21 hours some routes are deleted from the table and the server becomes unreachable. After restarting from the UI everything ...
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Unable to Connect to AMT on HP Z4 Workstation with MeshCommander Due to Unknown IP Address
I'm having trouble using MeshCommander to connect to the AMT in my HP Z4 Workstation because I don't know the IP address, and MeshCommander isn't finding anything. According to the HP Bios Simulator ...
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Enable option 66 and option 67 in kea dhcp
How can we enable option 66 and option 67 in kea dhcp. We are using kea dhcp version: 2.1.1
on debian. We could not find much about it, any help would be appreciated.
Thank you in Advance :)
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Freeradius dhcp relay
I have a freeradius v3 running on my raspberry pi together with pihole.
I have a external NGFW acting as a DHCP Server.
I want the freeradius to "forward" all DHCP requests to the firewall, ...
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Resolve different subdomains for different subnets with dnsmasq
I have a dnsmasq server with DHCP and DNS enabled. It serves multiple subnets. My goal is to dynamically register connected machines from different subnets on different subdomains. All of my subnets ...
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DHCP clients losing current DNS configuration after DHCP server goes offline
We have TWO Domain Controllers, one with DHCP and DNS roles installed(DC1) and the other with just DNS(DC2).
For a while the scope options did NOT include a second DNS as an option but it's been about ...
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How to retrieve DHCP information when using systemd-networkd?
Our Ubuntu 22 machines have networking configured using netplan and systemd-networkd. Network manager (and therefore nmcli & co.) are not installed.
In a bash script, I am looking to extract ...
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how to ingress correctly in kuberenetes with nginx-ingress
I'm new to k8s and I'm having slight trouble setting up a local cluster on virtual machines and have it be accessible from at least my host machine.
setup.
I've a local cluster consisting of three ...
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How to remotely add reservation to DHCP Server using PowerShell?
Administrators have restricted RDP access to our DHCP server.
I need to add an IP address reservation for a MAC address.
How do I remotely add an IP address reservation on the DHCP server using ...
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Why is MikroTik router DHCP server delivering ISP's gateway address in addition to router gateway address?
I am doing a very basic setup with a MikroTik router: an ISP modem in bridge (dumb modem) mode, a static public IP, router with DHCP server enabled, LAN. I have followed manufacturer's "Getting ...
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Can I run a DHCP server using Docker Swarm?
I am using PiHole inside Docker as my DNS server, I want to enable the DHCP server functionality but I am running in Docker Swarm and I am not certain if it can handle broadcast requests at least it's ...
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Detect DHCP poisoning with cheap hardware
DHCP snooping is a feature that allow switches to prevent DHCP starvation and DHCP poisoning (MITM attacks on LAN).
But these features are not available on cheaper, domestic equipment such as entry-...
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Windows Server - many event id 4625 authentication failures
In a small network environment, we have one Windows Server with Domain Controller, DHCP and DNS.
When every non-domain Windows client connects to the network, a lot of 4625 logon failure events are ...
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How to synchronize time between two devices on a local network using NTPD, with one device serving as both client and server on separate interfaces?
I am using STM32MP1 based two devices which runs on Yocto Linux platform. Among them one has two network interfaces (wlan0, wlan1) where wlan0 is used for connecting with internet servers & wlan1 ...
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In the event of a DHCP server outage and a lease time of 7 days, how long will a client keep using its assigned address?
There are a lot of questions about DHCP servers/clients/leases, but I haven't found one specifically addressing this.
If I set up a DHCP scope with a lease time of (say) 7 days, and the DHCP server at ...
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Unable to manage existing IP address ranges in IPAM after its installation
I have an environment with one Windows server that is running as DC, DNS and DHCP server. In my LAN, I have one network: 192.168.10.0/24.
On another server, I've installed Microsoft IPAM server (as a ...
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Combining DHCP with static IP using systemd
Basically I want to set a static IP with systemd, but I want to get everything else (read "the routes of the network") via DHCP. This is easily done on macos for example which has the option ...
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Ensuring Windows 10 computer joins correct subnet via DHCP
I'm setting up a proxy/firewall and I want it to be the DHCP server for windows clients. The problem is that if I set DHCP to automatic on the windows clients, they will sometimes select the network's ...
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DHCP starting before network is ready
I am having a problem with my DHCP server. When it restarts the isc-dhcp-server does not get ready because the network (it uses NetworkManager) is not ready.
I put a sleep command in the isc-dhcp-...
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DHCP moved from [closed]
After connecting several Raspberry Pis running Ubuntu 23.10 to my switch, they are for some reason stepping on each others DHCP leases. DHCP is running on fpsense 2.7.2... Logs:
DHCPREQUEST for 192....
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How to configure DHCP relay when NAT is also used?
I have a multi-homed application server that serves multiple networks that are not connected with each other (other than being all connected to the server, each one on its dedicated network interface)....
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How to mix DHCP-provided DNS servers with statically written DNS servers?
I am trying to make a combination of the DNS servers provided by my ISP and 3 static (8.8.8.8, 1.1.1.1 and 9.9.9.9).
On Ubuntu 18.04, I did it by adding the static DNS to "/etc/resolvconf/resolv....
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DHCP reservations by hostname and router lease
I'm French sorry if the wording is not perfect.
To give you a little context, I don't have any diploma in IT but I joined my colleague in the IT department of our company. He's been dealing with this ...
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Changing Subnet-mask
I am working at a school and recently there has been more and more devices that are not getting internet due to dhcp table being full. Pool size of our ip addresses is set to 242, but there are more ...
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KVM VM obtaining duplicate IP address for strange MAC address
I have a ubuntu KVM host on which Ubuntu virtual machine is created in virt-manager.
The VM is obtaining 2 different IP's from DHCP server which is running on Windows Server. 1st IP address lease ...
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DHCP and DNS on a custom internal vSwitch?
In Win 11 I've configured in Hyper-V a custom internal vSwitch with NAT as follows:
New-VMSwitch -SwitchName 'VM NAT switch' -SwitchType Internal
New-NetIPAddress -IPAddress '192.168.2.1' -...
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DHCP providing IP but not creating DNS A record
I'm having a problem setting up a virtual machine IP assignment via DHCP.
The virtual machine is a clean installation of Ubuntu Server 22.04 The DHCP server is a Windows Server Domain Controller.
When ...
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How would you set up a macOS laptop to maintain the same IP address between ethernet and wifi?
I have a situation where I need to maintain the same IP address and/or hostname between two network interfaces on several macOS laptops: the ethernet and wifi.
The topology is such that there is a ...
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IPv6 / Kea DHCP / Ubuntu 20.04 / DNS Server Issue
Here is my current setup:
I have IPv6 / IPv4 enabled in my environment.
My router is doing RA for that IPv6 subnet.
Router is configured with other options flag.
I have Kea DHCP6 / DHCP4 server ...
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Devices keep getting IP from previous VLAN
Some devices (printers and laptops) that are moved to another building with a different VLAN will not release the IP address assigned. I noticed this first when a laptop reported no network ...
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Upgrading an DHCP Load Balance environment - in-place upgrading 2012R2 to 2022
I've got an old DHCP environment, all on Win 2012 R2. 2 host doing Load Balance . We want to upgrade those to Win 2022.
That's something I've never done before (heck, I set this current one up like 10 ...
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Migrating DHCP To new server with same IP
I have DHCP being used across VLANs, so I want to keep the same IP address on my new DHCP Server. I have found many guides that make it look very easy to export/import dhcp records using powershell, ...
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Wrong DHCP-Adress when switching VLANs
I have a problem with our fairly new kea-dhcp setup. We have a bunch of different VLANs in use for which we want to give out DHCP-Adresses. For this purpose we use a little APU-box which serves our ...
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DHCP unicast packets processing in Linux
I'm trying to catch and process (in 3rd party analytics app) DHCP packets from ERSPAN session, but cannot do this. There is PHY interface which receive ERSPAN traffic and erspan-type interface to get ...
