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Questions tagged [dhcp]

DHCP is an auto configuration protocol used on IP networks.

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Override ISC DHCP's `option routers` with the absence of that option? [duplicate]

I was thinking I'd rather not assign my TV a default gateway, and since I use ISC DHCP 4.4 I tried to override the general subnet configuration with a host specific configuration, like this: host ...
Andreas's user avatar
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DHCP - Force install routing table to local computer

I would like to use my Ubuntu VM to act as a dhcp server and gateway for my work laptop, This laptop must connect to a Cisco anyconnect SSLVPN in order to access internal resources This VPN is not a ...
igor-root's user avatar
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dhcpd or dhclient not found

I'm working on a custom Ubuntu 20.04 server and am trying to get a dhcp IP for it. The server has so far run on a static IP and when I run dhcp or dhclient it says dhcpd: command not found and ...
user2384330's user avatar
2 votes
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how to extract option 43 from systemd-networkd's dhcp client?

Just like how dhclient captures dhcp response and stores it in env, is there a way to capture information like option 43 from systemd-networkd's DHCP client and store it in env ? I have proxy URL ...
kpn's user avatar
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Implementing Dynamic IP Fallback Mechanism with Connman

I am working on a Debian 11-based live USB distribution that utilizes Connman for network management. However, as this distribution may run on various computers with different network interface card ...
Dani's user avatar
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Is there a way to get the dhcp Vendor Class from dnsmasq's dhcp-script

Is there a way to get the dhcp Vendor Class from dnsmasq's dhcp-script? I created a basic script that echos the args and env, and it's not there dnsmasq-script[9471]: args=old *********** 10.159.163....
Gary van der Merwe's user avatar
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Configure IPv6 DNS server via DHCP in LXC container

I have an LXC container created and started as follows: sudo lxc-create -t debian -n mylxc -- --release bullseye sudo lxc-start -n mylxc sudo lxc-attach -n mylxc On the LXC host I have a DHCP server ...
carlfriedrich's user avatar
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How to "predict" a DHCP IP address?

Before launching a VM from my script, I need to figure out which IP address it will get. So I did: dhclient <interface> And this works, because dhclient uses the MAC address from the macvtap ...
Maestro's user avatar
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Programmatically query last DHCP lease time

I have a buildroot embedded Linux where I change the ethernet port settings (i.e. disabled, static or DHCP) from a C++ program. When switching to DHCP, it would be nice to determine when (i.e. ...
Niko O's user avatar
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systemd.network DUID, IAID and DHCPv4 clientIdentifier

I've set my NixOS to use: systemd-networkd: systemd.network.enable = true; and I have my interfaces configured something like that: networking { interfaces.enp5s0f0np0.useDHCP = true; ...
Mathieu Legrand's user avatar
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NetworkManager to use dhclient to reserve and set IP for wlan intf

I want to reserve and get assigned an pre-defined IP address for wlan0 interface on my client. I have set: # cat /etc/NetworkManager/conf.d/dhcp-client.conf: [main] dhcp=dhclient # cat /etc/dhcp/...
greengold's user avatar
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IPv6 wide-dhcpv6-client fails at random intervals

At first, the system runs OK and successfully negotiates an IPv6 address and operates as intended. After some time the system stops sending DHCP requests and IPv6 fails after the lease times out, but ...
fileinsert's user avatar
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dhclient process messes up the wrong interface

I'm using Debian Buster and I have two interfaces configured: eth0 and wwan0 (broadband modem). Here's the relevant part of my interfaces file: # The primary network interface auto eth0 iface eth0 ...
Alexandr Zarubkin's user avatar
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What are the consequences of blocking incoming UDP port 68 on my computer?

In a FreeBSD 13.1 install, I enabled the IPFW firewall and set firewall_type="workstation" in /etc/rc.conf. This allows outgoing requests, while denying incoming requests. When I checked the ...
Flux's user avatar
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I see only DHCP requests but not DHCP responses from "parallel" computer

I have two Raspberry Pies and one DHCP server connected to a switch. Raspi #2 is configured to do netboot. I am sitting on Raspi #1 and doing tcpdump 'ether host b8:27:eb:5d:4a:f6' -p -i eth0 -vv I ...
Dims's user avatar
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isc-dhcp-relay dhcrelay[1019]: Discarding packet received on ens37 interface that has no IPv4 Address

I have a topology that runs a DHCP Server, Relay, and Client. im using isc-dhcp-server & isc-dhcp-relay. Im using Debian 11 Bullseye on every server, I configure the service on each server. But ...
LM.'s user avatar
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Maximum number of static leases I can define in isc-dhcp server

I am trying to figure out the max number of leases I can define in dhcpd.leases file for the DHCP server. Does anyone know how many max can it support? Thanks
rashi's user avatar
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How to advertise hostname to router (via DHCP) in initramfs with dropbear?

I've setup the Debian package dropbear-initramfs to unlock my homeservers disk over SSH. Unfortunately, the router assigns a different IP to the server on every boot and its DNS does not know the ...
Thomas Koch's user avatar
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How do I set option 119 in systemd-network [DHCPServer]?

I've tried, among other things: SendOption=119:string:example.com tcpdump says "malformed packet" 0000 64 4b f0 1a 05 9a 00 e0 67 26 5b 13 08 00 45 c0 dK......g&[...E. 0010 01 50 ...
sea chub's user avatar
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ip is loosing after reboot, ntpd log : Deleting interface #4 eth0, ipv6

After rebooting computer, IPv6 address is lost. [root@VM-1-47-centos ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:...
Ccfeiker's user avatar
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Leasequery response in dnsmasq

I am trying to get leasequery response from dnsmasq server. This is the content of the /etc/dnsmasq.conf file: port=0 interface=eth1 bind-interfaces listen-address=1.0.1.4 dhcp-range=1.0.1.100,1.0.1....
rashi's user avatar
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How can I make NetworkManager use the global DNS settings from systemd-resolved for all interfaces?

I'm on Ubuntu 22.04 I've set some custom DNS servers in /etc/systemd/resolved.conf (systemd-resolved) I'm also using NetworkManager. The servers set in /etc/systemd/resolved.conf are 1.1.1.1 and 1.0.0....
Soren G.'s user avatar
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Does DHCP on dd-wrt support the absence of the default route?

I have one reason to flash dd-wrt onto my router (rt-ac66u), which is to be able to not assign any default route via DHCP. The stock firmware doesn't seem to be able to do this. Dd-wrt appears to be ...
Andreas's user avatar
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Is there an example dhcpd.conf that contains an example for each option?

OS: Debian 11 I'm attempting to create an example isc dhcpd.conf which has an entry for each option. So far I've managed to find about 30 options to include but I can't find the other ~160. I looked ...
Arkham Angel's user avatar
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Device connected to local network with IPv6 despite noipv6 setting

In dhcpconf.conf file I have set noipv6 in the section of interface used for the connection, in past this apparently worked, now the device has assigned both IPv4 and IPv6 as I can se from inet6 ...
AndreaF's user avatar
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Ubuntu 22.04 dhcpd restart on docking station interface reconnect

I have setup on my desk, where Ethernet connected device is plugged into port of my USB-C docking station (same that powers the notebook). I've configured isc-dhcpd to work on enx3ce1a14ec0bd ...
Michał F's user avatar
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How to assign different ip's on cloned systems (no VM's, embedded systems)

After some research, I am not being able to solve assigning different ip's on cloned systems. Most questions reference working on VM's. I have an embedded system, I will call it Master: Google Coral, ...
M.K's user avatar
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Is rc.local the best place to add a pon start and network routing change?

I've followed this guide to get a 4G hat networked with my pi zero, and everything seems fine. I'm able to ping out once pon has started in the background and a route has been added. What I want is ...
Harry Lincoln's user avatar
1 vote
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186 views

DHCP server for a Network Manager bridge connection using dnsmasq-base?

With Ubuntu 22.04 on a Raspberry Pi 4 I bridged (br0) the connections for ethernet (eth0) and WiFi (wlan0) using nmcli. That seemed to work fine, with WiFi acting as an access point. When I used the ...
Andreas's user avatar
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530 views

Debian 11 setting DHCP for 2 or more client networks

I have 2 bridges (vmbr1 vmbr2) on proxmox server. vmbr1 IP: 192.168.106.1 for NAT clients vmbr2 IP: 192.168.107.1 for Local only I have set up DHCP server (isc-dhcp-server) and it works perfectly with ...
Eki's user avatar
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dhcpd snap-in directory not found

I am running dhcpd on Linux system all the subnets information, reservations n all are written in dhcpd.conf sometimes we need to make client system's IP static and it will become very difficult to ...
csx4's user avatar
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1 answer
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How does debian select a dns server when there are multiple NICs with DHCP

recently I had to add another nic to one of my VMs and noticed a few hickups. Turns out that NIC2 overwrote the DNS settings obtained by the dhcp server on NIC1. I could obviously make that static, ...
Ehtor's user avatar
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Fedora 24 dhcpd.service is not starting

Error Code Nov 30 23:36:00 Projserver.nspdom1.local dhcpd[2627]: This version of ISC DHCP is based on the release available Nov 30 23:36:00 Projserver.nspdom1.local dhcpd[2627]: on ftp.isc.org. ...
Ali Raza's user avatar
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1 answer
367 views

Configuring fixed IP address based on MAC with dnsmasq give duplicate IP error

In order to allow monit to use ping to check whether devices are 'up' I want to have fixed IP addresses. I am using dnsmasq and have a separate file to configure these. e.g. dhcp-host=00:27:02:13:be:...
David Norbury's user avatar
1 vote
1 answer
352 views

Trying to figure out my ipv6 address but getting multiple options

ip -6 addr Prints a whole lot of actual addresses: inet6 <addr>/128 scope global dynamic noprefixroute valid_lft 999612sec preferred_lft 394812sec inet6 <addr>/64 scope ...
transient_loop's user avatar
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73 views

Wicked lease file

Sorry for the probably silly question but I'm new to openSUSE and Wicked tool. I have an XML lease file and I don't quite understand the purpose of some tags. <lease> <family>ipv4</...
23ars's user avatar
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1 answer
197 views

How to setup gateway on second DHCP server?

I need to add a static route to my internet service provider's router. Unfortunately, this router does not provide such a modification option for an end-user. The reason I need the static route is so ...
bomben's user avatar
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Wi-Fi DHCP debugging for cell phone needed

Every then and now, my android cell phone cannot connect to my Wi-Fi and says: unable to obtain IP address. After some time (sometimes minutes, sometimes hours) connection is back to normal. This is ...
Reinhard Mayr's user avatar
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48 views

WiFi router assigning different hostname despite sending gethostname()

For some reason my wifi router is assigning an altered hostname to my linux device. The hostname on my device is for example shserver2, my CLI login shows me@shserver2: and my /etc/hostname file ...
ShaunMc's user avatar
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6 views

Preferring cable over WLAN connections from the other end

Imagine a home network with an internet router that assigns DHCP addresses to all the connected machines. It has a dynamic DNS server that learns the hostnames of attached machines from their DHCP ...
Juergen's user avatar
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212 views

Configure hostapd with different dhcp_server - Error: unknown configuration item "dhcp_server"

I've installed AlmaLinux 9.0 on a machine with eth/wifi ports. The machine connects to my network via ethernet. I want to set the machine up as an AP for wifi clients within range using hostapd. I've ...
dan's user avatar
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1 vote
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311 views

DHCP - Why is having a DUID causing dhclient to fail?

My computer's DHCP client fails during boot. If it doesn't fail, it takes an unreasonable amount of time to acquire an IP. The main symptom is that this shows up during boot: A start job is running ...
Aloha's user avatar
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4 votes
1 answer
165 views

Systemd-resolved setting unexpected DNS list

When I connect to my phone hotspot I would expect systemd-resolved to use the DHCP-provided DNS list. For some reason it seems to not be the case for me. I am using Ubuntu 22.04.1 LTS /etc/systemd/...
Marcin Król's user avatar
2 votes
1 answer
374 views

dnsmasq dhcp not listening on port 67

I'm trying to host a DNS and DHCP service with dnsmasq. Here is my dnsmasq.conf # DHCP dhcp-authoritative bind-interfaces dhcp-range=192.168.122.2,192.168.122.99,12h dhcp-leasefile=/var/lib/dnsmasq/...
qMo's user avatar
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216 views

Automatically refresh DHCP on wpa_supplicant (dis)connect (Debian 11)

I have access to a Wifi SSID which works with the same credentials but it might access different access points with those credentials. This is a service by my provider that lets you connect to other ...
Preau's user avatar
  • 111
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1 answer
301 views

QEMU: where is dhcp configuration file for vmnet-shared

When I run virtual machine and attach vmnet-shared IP address is assigned from DHCP Question: Where do I find dhcp default configuration file on MacOS?
Rafal Niznik's user avatar
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1k views

Setting up a fixed IP wifi hotspot (with no internet) with DHCP and DNS using dnsmasq

I'm having trouble setting up my computer (running Ubuntu 18.04) as a hotspot with a manually fixed IP. I want devices to be able to connect to it via WiFi, and for them to be able to access my ...
kekpirat's user avatar
  • 101
0 votes
1 answer
2k views

Debian 11 dhcp assigning ip to more than one interface

We have a server to which more than one interfaces (say eth0 and ensp1) are connected to fibre. The two connections are necessary because this machine is used by multiple work, is remote and so ...
user2714795's user avatar
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0 answers
87 views

DHCP on two Interfaces

Hello i have an Computer with two Interfaces eth1 and wlan0. What happen if i connect my Raspberry pi with a running DHCP on eth1. If a Device on the wlan0 Network request an IP Adresse is this ...
Anton Pytlik's user avatar
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34 views

check DNSv6 advertised in router advertisement

I see that tcpdump can show router avertisements or ICMPv6 messages but I would like to see if the DNSv6 that is advertised by the router is the correct one as I use pi.hole and it should advertise ...
Marc Elser's user avatar

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