Questions tagged as ['dhcp']

The Dynamic Host Configuration Protocol (DHCP) is a network configuration protocol that assigns IP addresses and gateway configuration automatically.
Score: 0
Naveen avatar
Unable to set dhcp server on Ubuntu 20 desktop
br flag

On my Ubuntu 20 desktop machine, I am using Wifi for internet and hence my LAN interface is free. So I want to use it as a DHCP server interface.

eno1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether b4:2e:19:c6:73:57  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        T ...
Score: 0
Dan Hendli avatar
How to access ubuntu server on two diferent public ips
cn flag

I'm strugling with the current problem:

Background info: Ubuntu 20.04 on dell R710

I have 2 diferent internet connections with 2 isp supplied routers. I've connected eno2 to isp1 router and get the ip via permanent dhcp lease. I've connected eno3 to isp2 router and get the ip via permanent dhcp lease.

ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue sta ...
Score: 0
Ubuntu 20.04.3 autoinstall Network Issue dhcp
in flag

Currently I have a small ssh network problem. I use an Ubuntu 20.4 Server Edition incl. autoinstall. I removed the network configuration from my user-data file because it should be better for the installation to select the adapters itself. Now I have the problem that after the first reboot my packer script cannot connect to ssh.

Only after entering the command dhclient -r and dhclient the packer  ...

Score: 0
Minsky avatar
Can we set up a DNS server to override the Router DNS server?
mx flag

I am aware that when we type a domain name, unless it is cached in the pc or router, it requests the DNS to an external server, to get the IP address.

Apparently, the DHCP server from the router is setting itself for DNS ( Issuing systemd-resolv --status or resolverctl status gives

Link 3 (wlp1s0)
      Current Scopes: DNS
DefaultRoute setting: yes
       LLMNR setting: yes
MulticastDNS  ...
Score: 0
Empusa avatar
How to get IP from a DHCP server sitting on a sibling VM?
de flag

I have an Ubuntu 20.04 LTS server at home which I use as a media server and other entertaining purposes, inside which I have installed Google's 2 factor authentication and with external access via zerotier "vpn".

Recently I got the idea of getting some courses done, like AD, Intune, Networking, therefore I have built 3 VM's (kvm with Cockpit interface). One is a domain controller and the other 2  ...

Score: 0
Kingfranz avatar
How do I stop DHCP to request address for a static interface?
cn flag

I have a Raspberry PI 4 running Ubuntu 21.10 with a static ip-address on eth0. Despite that, I keep getting a secondary 'dynamic' DHCP address on on it.


  version: 2
  renderer: networkd
        - to: default
          search: [lan]
          addresses: [192. ...
Score: 0
ISC DHCP Server - Assign the same IP without static host config
in flag

Is there a way to configure the DHCP server to assign an IP to a client without the client being statically defined.

My main goal is to create an IP pool that will keep the IPs reserved for 30 days as an example. If there are no requests from the client within these 30 days, the IP will be released again. Otherwise, the one and the same IP should always be assigned beyond these 30 days.

Score: 0
No DHCP after power cycling my Ubuntu box
gf flag

I am running Ubuntu 20.04. Some time back I removed the snap package manager from it. Network Manager is not running on my system as reported by 'service --status-all' and 'service network-manager status'.

Also systemd-networkd service status is loaded but inactive.

The physical interface enp1s0 has no IP address although it is connected to a router with an active DHCP server.

Score: 0
Configuring an external DHCP server for MAAS to provision bare metal server
vu flag

We are using MAAS 3.1 and are working a lab where there is already a DHCP server provisioned to allocate IP. As a part of MAAS provisioning a Bare Metal Server we want it to use the external DHCP server instead of the default one within in MAAS. The dhcp configure doc link from MAAS does not provide much info about how to configure an external DHCP server. Any info related to this procedure will be ...

Score: 0
Ubuntu 18.04: DHCP server is not giving out IPs to my DHCP client
mx flag

I need to setup a DHCP server and client. I tried everything, but my server isn't giving any IPs. I work with VMware, and I have disabled the DHCP setting in VMware. My DHCP server states active to.

netplan of my DHCP client and DHCP server status

netplan client config:

      dhcp4: true
        addresses ...
Score: 0
Gitnik avatar
Ubuntu 18.04 server unreachable after setting static IP
sl flag

I've configured netplan to set static IP for a server on my local network. However, after sudo netstat apply server just becomes unreachable. When I check the router, I can see it listed with assigned static IP (after waiting for a long time), but it's still unreachable. Does it have something to do with modems default settings that were provided by ISP? Here is my netstat config:

Score: 0
rth avatar
cannot boot diskless station after update to Ubuntu Server 20.04
pk flag

I have a configuration which worked pretty well over a few years, until latest update to Ubuntu Server 20.04. I have a head node: tftpd-hpa which provides pxelinux.0, kernel, initrdfs and booting parameters:

root=/dev/nfs initrd=node-initramfs nfsroot=auto ip=dhcp rw

The headnode also runs isc-dhcp-server with follow configuration

default-lease-time 3600;
ddns-update-style none;
deny booting;
deny bootp ...
Score: 1
My local DNS is continuously changed
hu flag

At home I run a Raspberry Pi with PiHole. Every device obtain its IP via DHCP and some devices have a reserved address. The router is configured to offer my Raspberry Pi as primary DNS, for every device this works well, except for my laptop with Ubuntu.

Quite often (like every day) my DNS is changed to my second DNS option. I can revert this change with resolvectl dns <interface> <ip>

Score: 1
Prevent routing of DHCP traffic
ng flag

First, I'm aware that similar questions to mine have been asked elsewhere (I've read many of those posts!) but I've not been able to figure out a solution to my problem, so I'm asking for help.

My setup

I have two networks on my LAN, and The former has DHCP running on my WAN router, the latter runs dnsmasq on Ubuntu Server 20.04 on a box that also serves as a router b ...

Score: 1
wunschwaschbaer avatar
Activation of network connection failed, DHCP timeout
be flag

After a few hours of trial and error, i guess i need some help...

Problem is the following: I am trying to connect to a WIFI network, which has worked for me for the last three months and started to make trouble just three days ago. 19 out of 20 times I try to connect, i get "Activation of network connection failed", 1 out of 20 times it works for some reason. This problem only occurs on my Ubunt ...

Score: 0
netplan networkd no ipv4 from dhcp
ke flag

I've been trying to have ubuntu server running on my MacBook Pro (15-inch, Late 2011) for the whole day, both 20.04 and 21.10, fighting with netplan and I cannot seem to be able to have ens9 (Thunderbolt 2 network adapter - seems to work fine from this post: Using Apple Thunderbolt 2 Ethernet adapter on Ubuntu 20.04) getting an ipv4 from the DHCP. I read tons of posts all over the place, it seems trivial  ...

Score: 0
random person avatar
Ubuntu Server 20.04 installing a dhcp without internet access
br flag

I've just recently set up my Ubuntu Server 20.04 and now I'm trying to install a DHCP server.

But it always fails because I get

Temporary failure resolving ''

Is there any way I can set up my network without internet access? Are there any alternatives?

Thanks in advance

Score: 0
AlexSwamp avatar
I want to multi DHCP server
in flag

I want to use multiple subnet with multi interfaces.

-> trunk.102
-> trunk.103

... etc

Does it works well or need more something? How can i order to trunk.102 use subnet or trunk.103 use subnet?


default-lease-time 600;
max-lease-time 7200;
ddns-update-style none;

subnet netmask 25 ...
Score: 1
MaGaroo avatar
NetworkManager: IPv6 Automatic Modes
pt flag

I was looking at the IPv6 config of my Ethernet connection in NetworkManager's connection editor. It seems there are 3 automatic modes alongside other options:

  • Automatic
  • Automatic, addresses only
  • Automatic, DHCP only

Can anyone help me with the differences between these options?

P.S. There are 2 following options in IPv4 settings and their difference is obvious to me.

  • Automatic(DHCP)
  • Automatic(DHCP) ...
Score: 0
Create a loopback, masked ip?
cn flag

So, I have a project on my Ubuntu 18.04 LTS (64bits) VPS that don't work with the normal IP (like, it only work with a network mask. The problem is that I can't manage to mask it correctly, because I always get these errors:

SIOCSIFADDR: File exists
SIOCSIFFLAGS: Cannot assign requested address
SIOCSIFNETMASK: Cannot assign requested address
SIOCSIFFLAGS: Cannot assign requested addre ...
Score: 0
Anna Naden avatar
Periodically, dhcp4 trashes my wifi adapter's IP address
cn flag

A few times a day, I lose WiFi connectivity. When I have connectivity, the IP address of my wifi adaper is When I don't have connectivity, the address is syslog shows Network Manager dhcp4 setting this address.

I tried enabling manual adapter settings but my browser doesn't work, probably because I don't have a DNS server address entered.

How can I get dhcp4 to cooperate, ...

Score: 0
MAC address filtering based on manufacter ID
cn flag

Good morning, I'm going to implement a DHCP server that needs to accomplish following configuration:

  1. it will manage 3 sub-network from base, so I'll have 4 networks.
  2. the DHCP server, then should lease IP to clients based on MAC address manufacter ID as: Manufacter AA:BB:CC:xx:yy:zz should fall in network up to 126 Manufacter DD:EE:FF:nn:mm:oo should fall in network 19 ...
Score: 1
Ethernet connection not working - Network activation failed
ki flag

So I am aware there are similar problems out there however I could not solve mine with any of the solutions so far:

I am trying to connect to a LAN network from my Thinkpad P14s (Intel) running with Ubuntu 20.04 Desktop. I keep getting: "Activation of Network connection failed" and I am running out of possible solutions. I do not have access to a router and the exact same cable connection works e.g. ...

Score: 0
Nickolay Khalaychidi avatar
Ubuntu Server 20.04 network config
tr flag

I have Ubuntu Server 20.04 installed in virtual machine on my Windows Hyper-V host.
I'd like it to get IP address from my Windows DHCP-server in local network But it doesn't work and I don't know why. Virtual machine with Windows with same configuration works fine.

ip a output:

1: lo: <L00PBACK,UP,L0WER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
 link/loopback 00:00:00 ...
Score: 0
DevOpsSauce avatar
DHCP address keeps getting generated with netplan and bonded interface
eg flag

I have a bonded interface set up with netplan. Config is as follows:

# This is the network config written by 'subiquity'
            addresses: []
            - eno1
            - eno2
                addresses: [,]
Score: 0
How does network setup internally work on Kubuntu / Systemd?
sa flag

My networking seems to be totally screwed up. This is why I want to understand how network setup on (K)Ubuntu is supposed to work. Which components are involved and how they are meant to work together.

I know this question and my problems create two totally different topics. Let's see how this discussion is going to be and then I clean up to make this thread as generic as possible or create two t ...

Score: 0
DHCP is not starting in Ubuntu 18.04
jp flag

Im on ubuntu 18.04 ( also tried with ubuntu 20.04)....but i cant run isc-dhcp-server

osboxes@osboxes:~$ sudo systemctl status isc-dhcp-server
● isc-dhcp-server.service - ISC DHCP IPv4 server
     Loaded: loaded (/lib/systemd/system/isc-dhcp-server.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Wed 2021-11-10 17:06:48 CET; 13min ago
       Docs: man:dhcpd(8 ...
Score: 0
Thomas OHern avatar
Netplan config for either Static or DHCP depending on SSID connection
ke flag

I have a server that will either connect to one of two wireless SSIDs. On the first, I need a static IP and on the second, I need a DHCP IP. I know that I can set both a static IP and DHCP to true on the same interface and it works, but the default route always ends up being for the static IP so outbound connections always fail when connected to the DHCP network.

Is there something I am missing ...

Score: 0
problem setting up pxe boot with diskless client ubuntu 20.04 (dnsmasq,nfs server) ltsp like
cn flag

i have been struggling for the last 3 weeks setting up some thing like ltsp. we have a call center with 50 + client with 2G ram which is not enough, and a beafy server with 64 G ram. we used to use Ubuntu 16.04 with ltsp5 and it was a perfect solution for us as clients only need firefox and a softphone, but new ltsp is not supporting the thin client anymore, client boot up as fat client (using client ra ...

Score: 2
No network from minimum net install
mx flag
  • I did a minimum net install, but my new system is not starting the network automatically -- No IP address with my eth0 device.
  • I installed dhclient package myself but that doesn't help. I thought it should have been taken care of by the post-install of the dhclient package.
  • Searching for the answer myself, I found this page, hinting that I have to write such systemd unit for myself.
  • If so, I hav ...