Questions tagged [dhcp]
DHCP is an auto configuration protocol used on IP networks.
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Debian: How can I use the command line to invoke a network interface to request a DHCP IP address?
The question is the title, but to elaborate:
I have a server with an Intel i350 T4 (4 port NIC) and currently 2 of the cables are plugged into my switch. One of the NICs has a DHCP aquired IP address. ...
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How to PXE boot of Raspberry PI along with other computers?
I have a LAN with PXE boot configured. Any PC computer if configured, presents me with PXE DHCP information, then netboots and presents me with pxelinux menu.
If I remove SD card from my Raspberry PI ...
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How to intercept hostname changes in order to update IP based on DHCP IP plan
We're using Rancher for the provisioning of Kubernetes clusters using a VMWare vCenter integration whereas Rancher interacts with the vCenter API in order to provision the Kubernetes nodes.
The ...
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17 views
How to get netplan to set the dns server in /etc/resolv.conf based on info coming from the dhcp server?
I'm setting up a 4 x RPi Cluster with the following simple network topology:
All 4 RPi nodes have the latest Ubuntu Server LTS 20.04 OS. rpi1 is my primary/gateway node. I did the following on rpi1:
...
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11 views
Can't connect to DHCP server on CentOS
I am trying to get a FOG server working with CentOS (installed in VirtualBox). As part of its install it installs a DHCP server. At first I thought it was an issue with PXE boot, but I have tried ...
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14 views
How do I set up a bridge network with KVM where the virtual guest is acting as DHCP server?
I want to run a virtualized pfSense server on a KVM host (Debian 10) along with some other virtualized servers. I have a NIC expansion card that I want to passthrough to pfSense. The host machine will ...
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33 views
systemd-resolved is not using the DNS servers provided by DHCP - using mysterious IPv6 addresses instead
At home, my router provides DHCP (192.168.1.1), and another server hosts a local DNS cache (192.168.1.157). I do not have a DHCPv6 server.
The router is correctly set up, and the only nameserver it is ...
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1answer
26 views
Why is the server accepting connections after disabling the network interface?
I've googled around and executed other commands (I had left here only the ones that I think are more useful). Most searches pointed me to explanations about how to shut down/up interfaces and no hints ...
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1answer
44 views
How to force libvirt to use the host dnsmasq service?
Libvirt has one defined network, which uses dnsmasq as DHCP/DNS server. But this dnsmasq is a separate instance (config in /var/lib/libvirt/dnsmasq/default.conf), which creates additional dnsmasq ...
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Would DHCP client renew after detecting link changed
I did below experiment with some devices.
prepare a DHCP server
prepare another device with DHCP client (dhclient was used)
client got its IP
I tried to link down and link up of client, and checked ...
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Linux can only connect to AP with static IP, has no Internet connectivity (not a router issue)
A Linux laptop can only connect to its AP with a static IP. Once connected it can’t ping any local or external IP.
The router has no issue with any other device.
I have tried restarting DHCP, ...
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19 views
Router Disconnecting randomly ! Bad Password?
I have been facing this irritating issue lately, and have exhaustively searched for simmilar issues online but didn't got it solved yet.
I am using a dual band router.These are the present settings of ...
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1answer
149 views
DHCP and fallback IP - Can I have two different settings on the same network interface?
I have a project in which a user can change the RPI's networking settings via a Web Interface from the following:
DHCP WiFi
DHCP Ethernet
Static WiFi
Static Ethernet
Each choice re-configures ...
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41 views
netctl: Static IP configuration lost automatically after few seconds of starting the interface
I am using netctl in Arch Linux on Hyper-V. I have two ethernet interfaces eth0 & eth1.
IP config:
eth0: dhcp (automatic configuration, no involvment of netctl)
eth1: static ip (10.10.10.1/8) ...
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1answer
82 views
Set up Debian networking bridge with DHCP
After a recent bout of package upgrades (but still within the stretch release) my bridge networking to support libvirt VMs seems to have died - the DHCP server does not send an IP to the host nor does ...
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1answer
13 views
Minimal instalation CentOS USB modem LTE internet doesnt work
i am using Huawei USB stick. Unfortunatelly i cannot connect to the internet. Its problem somewhere in DHCP i guess. But i dont know.
Could somebody help me ?
enter image description here
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ISC DHCP dhclient: How to supersede DNS name servers with IPv4 and IPv6 addresses?
I want tp supersede the name server information, which I get from the DHCP server with my own configuration. Therefor I'm using the following option in my /etc/dhcp/dhclient.conf:
supersede domain-...
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1answer
38 views
Why do we need to have an ip6tables rule for DHCP6 to work? (by contrast, IPv4 does not require any)
Why do we need to have an ip6tables rule for DHCP6? (IPv4 does not require it by contrast)
Here's minimal IPv4 rules written by me, you see no special DHCPv4 (Wikipedia) rule:
IPv4: iptables --list-...
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1answer
465 views
Static IP and DHCP Lease in dnsmasq?
I'm setting up a couple of Raspberry Pi's on my router's DMZ (don't worry all the ports are closed); my router uses DNSMasq for DNS and so I added the MAC addresses; hostnames and IPs of the pi's to ...
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Searching for a way to detect roogue DHCP Servers on OpenWRT
I know there are a few tricks and tools out there to detect DHCP servers (rogue or not) on my local network.
But I need one working under OpenWRT.
Could anybody help me with suggestions, please?
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27 views
AP not responding to DHCP requests
I want my wireless interface turned into AccessPoint to be able to assign an IP address to the client that attempts to connect to it. not much right?
For making an interface AP, I'm using npm's ...
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1answer
70 views
Send packet on one interface and receive it on another one for testing purposes
I would like to test the DHCP client that I wrote on Ubuntu 16.04.6 LTS. I would like to do it locally on my laptop i.e. send and receive DHCP packets inside.
Here is what I tried:
created two dummy ...
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How to set up grub to use dhcp during book for autoyast install
I can do something like this:
linuxefi /book/x86_64/loader/linux netdevice=eth0 install=cd:/ lang=en_US autoyast=http://192.168.0.33:8080/~petturn/autoyast-xfs.xml textmode=1 ifcfg=eth0=172.18.48.24/...
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31 views
Pass DHCP user class in netplan
Is it possible to pass a DHCP option 77 and/or DHCPv6 option 15 in netplan using the networkd backend. Currently networkd supports passing DHCP option 77 and I believe there is work on adding the ...
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1answer
23 views
set the router's static mac address via isc-dhcp-server
Is it possible to set an ip with its relative mac address so that the clients (during the DHCP request) in addition to receiving the various data, will also directly receive the mac address of the ...
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1answer
199 views
Reverse Lookups to Local DNS Server Failing on Ubuntu 18.04
On Ubuntu 16.04 REVERSE lookups to a local DNS/DHCP bind9 server on the local network are SUCCESSFUL, while on the other hand, on Ubuntu 18.04 (and higher) the REVERSE lookups FAIL. All systems are ...
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18 views
Linux HTTP server Network Settings
I'm having a hard time to find a network configuration for a system that I'm developing. I start by stating that I'm not a network expert, so i'm sorry for something that is not so well explained.
I'...
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1answer
84 views
Is there a way to renew a DHCP lease for another client?
I am looking for a way to renew a DHCP lease for ANOTHER client, that the one making the request. I know how to do this for the requesting client using dhclient or arping, but I have this old router ...
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1answer
45 views
Does a DHCP server assign MAC addresses to network computers?
I have been working on basic Linux network configuration. I am aware that IP addresses, default gateways, subnetmasks etc are assigned by a DHCP server but am unsure if MAC addresses are assigned by ...
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Set router inside DHCP server
I'm building a network as follows:
A server with two network cards. One used for connecting to internet and the other for the internal network.
The internal network is set up using DHCP, I configured ...
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0answers
23 views
Network Settings in Linux -> Multiple IPs
I'm not by any means an expert on networks nor Linux. And I'm trying to solve a network related issue in Linux.
I have a server that I want to make accessable in two different networks (local network ...
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1answer
84 views
dhclient.conf modifications do not change resolv.conf
When I modify my /etc/dhcp/dhclient.conf with prepended nameservers, after a network manager restart, the generated resolv.conf file does not contains these servers. I'm working on Kali Linux.
Here ...
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1answer
74 views
How to automatically change DNS nameserver
My ISP's DNS server has problems resolving lots of important websites like google, github, gmail etc. As a hack I manually edited the /etc/resolv.conf file to Google's 8.8.8.8.
But the changed file ...
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1answer
85 views
dhcpcd dhcpv6 times out after Router Advertise, never sends a DHCPv6 Request
I use a linux host as an IPv4 router and looked into enabling IPv6 (it's the future, I'm told). I already use dhcpcd as a dhcpv4 client to get an address from my ISP, so I figured I'd use it for ...
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27 views
Run script on obtaining custom vendor option in Stateless DHCPv6 client
I am using Ubuntu and this question is regarding DHCPv6.
After obtaining RA (router advertisement) with O-bit ("Other configuration" flag) set to 1, an information-request is sent by the client.
...
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Passthrough of OpenVPN clients to local network
Ahoy friends.
Unfortunately i don't have that much knowledge about OpenVPN but at least i want to try to get my idea working.
Currently i'm using a VoIP device connected to my local area network, and ...
0
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1answer
27 views
Always trying to connect to wifi, but never connects, ping 8.8.8.8 results in “connect: network is unreachable”
I just bought a Raspberry Pi 4 which uses linux as its operating system.
I was just trying to browse the internet using my phone hotspot when the connection suddenly drops, I can't access any other ...
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25 views
How to setup a network card IP to be dynamic first DHCP, but to have static IP as fallback in CentOS/RHEL?
In CentOS7/RHEL7, ideally already via a kickstart configuration a network card should be setup in a way to attempt getting dynamic IPv4 address via DHCP and if no DHCP lease is available (after some ...
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2answers
47 views
Is DHCP client of any use on my desktop computer?
Is DHCP client of any use on my desktop computer?
I use my computer mainly for office purposes (web browsing/media consuming/libre office).
As I am setting up some firewall rules, I wish to restrict ...
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2answers
44 views
Where is DHCP data stored on OpenBSD?
I'm currently testing with some DHCP and I'm wondering how I can verify if options like "option host-name" or "option domain-name-servers" really worked on the client machine (OBSD 6.6). Where does it ...
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1answer
149 views
Configure ntpd to find local NTP server(s)
I'm currently designing a system (a physical system that can be used where ever) and have run into the issue that on some networks internet NTP servers can be blocked (by a firewall). In those cases ...
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3answers
59 views
Setup static IP address for 1 machine and DHCP for other
I'm using my Laptop on several networks. When I'm at home or at the office I occasionally want to connect with my phone to a server running on my laptop (say MPD, ssh, transmission).
The problem I'm ...
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43 views
Request a specific HOSTNAME(OPTION 12) from specific ip from DHCP server
Is it possible to request the hostname (OPTION 12) from a specific ip without having to intercept the DHCPREQUEST (and therefore wait for the device to disconnect?)
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1answer
72 views
Networking - VLAN & Router Linux
I have a setup with 1 Debian router + 1 Debian DHCP Server.
I need to create multiple VLAN on my DHCP server. From my DHCP server I have internet access.
I managed to create and set up my VLANs and ...
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0answers
8 views
Dhcpdump problem redirect output
I noticed that when I run the dhcpdump command everything works correctly (obviously) and everything is shown on the screen. But if I try to redirect the output to a file, for the first few minutes ...
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312 views
Can't Enable isc-dhcp-server on boot
I've installed DHCP Server on Proxmox/Debian and did the required configuration for it to be ready for use. However when I run the command
root@debian:~# systemctl enable isc-dhcp-server
isc-dhcp-...
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0answers
32 views
Ubuntu Desktop broadcasts hostname, but Ubuntu Server does not
In short,
I have four VM's running on Hyper-V as a Docker/Kubernetes Cluster.
The Master is an Ubuntu Desktop 19.4 instance.
The Nodes are all Ubuntu Server 19.4.
All the images have exactly the ...
0
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1answer
29 views
Prevent DHCP queries for a particular interface
I have a laptop with a Wi-Fi card and an Ethernet card, both connected to the same network. Despite my best efforts to disable the Wi-Fi, my system keeps trying to obtain an address for it, not only ...
2
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1answer
213 views
udhcpc: DHCP option 66 variable tftp contains “bad” if DHCP server provides IP address instead of hostname
I am working on an embedded Linux which uses BusyBox and udhcpc (part of BusyBox) as its DHCP client.
If I configure the DHCP server to deliver an FTP server in the DHCP option 66 everything is fine (...
3
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1answer
587 views
Disabling automatic default route from dhcp server
Hi I'm trying to configure my Raspberry PI to work as a dhcp server. Idea is that through eth0 interface I will connect switch, to which I can connect other devices. But I still want to keep ssh and ...
