Questions tagged [dhcp]
DHCP is an auto configuration protocol used on IP networks.
513
questions
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1answer
16 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 ...
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1answer
31 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
33 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 ...
0
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34 views
Issue with Internet connection on fresh Arch install
I am trying to connect to the Internet via Ethernet on a freshly installed Arch Linux system. I am following this YouTube tutorial.
Once I got to the Internet part, I started having issues. I cannot ...
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0answers
8 views
Why ISC KEA DHCP (DHCPv4) does not release an IP that has heen reserved and now released?
I reserved an IP ("reservations") for a MAC ("hw-address"). That MAC was
removed from my subnet and the IP was reserved for another MAC. That another MAC cannot "get" the IP that is now reserved for ...
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0answers
29 views
Ubuntu Server connected to 2 switches can't ping outside local network
To summarize, I just want to ping from the server.
Dell Server Running Ubuntu Bionic
Motherboard with 2x10Gb port => Connected to LAN switch
Extra Network Card with 2x1Gb port => Connected to ...
0
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0answers
12 views
Keeping isc-dhcp-server running even if there's no subnet
I use isc-dhcp-server to provide IP addresses to some instruments that connect intermittently via a USB-to-Ethernet adapter, addresses in the 192.168.1.0/24 range.
If the adapter is not connected when ...
0
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1answer
62 views
How to verify static LAN IP assignment to USB0
A Raspberry Pi 3B+ is configured
with Raspbian
with a working wifi: pinned to a static LAN IP address
Per the procedure: a static IP 192.168.42.42 assigned to the rPi's USB0 interface. Append: ...
0
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1answer
49 views
Theoretical: TAP interface w/ WIFI parent interface
I'm trying to create multiple Linux TAP interfaces and allow them to send/receive packets over a single WIFI adapter. For all intents and purposes I'd like the TAP interfaces to act as full fledged ...
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0answers
17 views
Can I configure a manual link-only IP address?
I've recently purchased an unmanaged switch, and I'd like to have a number of devices wired to it via ethernet, communicating solely with one another (the use case is "wifi for the outside world, ...
0
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0answers
12 views
Rasp Pi Stretch Swapping between Access Point Mode and Client Mode Displaying Errors Long After state change
I have a product, based on the Raspian Lite Stretch OS for the Raspberry Pi 3.
On wlan0 we swap back and forth between Host Access Point Mode and Wifi Client Mode using the CLI commands
Host AP => ...
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1answer
62 views
DHCP lease table in router shows weird entries when connected to Linux server
I have a domestic server where a MitraStar ADSL router is connected to a bunch of mobile devices plus two desktop machines (one Linux and one Windows) connected by Ethernet cables. IP address 192.168....
0
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1answer
39 views
Can a dhcp client select its server? How?
We have a bunch of IOT gadgets which will share cabling with a customer's regular LAN. We would like them to be logically separate. Let's say the regular LAN uses 198.162.x.x, and we want to use 10.10....
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0answers
20 views
Build DHCP server ubuntu 16.04 on KVM
How to build an DHCP server with ubuntu on KVM ?
I have try some guide but when the DHCP client turn on, the interface will use the IP from the KVM network not from the DHCP server i just build ...
0
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1answer
25 views
SSH only working shortly after router reboot
I am trying to create a homemade server. I'm running Ubuntu 18.04 and have an Xfinity router. I've forwarded port 22 to a reserved local IP for my server.
The problem is that I can connect via a ...
0
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1answer
22 views
Dhcp leases starting point
I have a linux server which acts as a dhcp server. Dhcp lasse range is 10.15.0.50 - 10.15.255.250. The first ip it leased is 10.15.80.10 Is there any specific reason for this? It keeps leasing ips ...
0
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1answer
61 views
How to make Debian 9's DHCP client check more frequently?
We're using a Debian 9 install on a Minnowboard (a small, embedded system). The Debian 9 install is nothing special - it's the regular Debian 9 image that we got from the Debian website, and had to ...
0
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1answer
27 views
How to release (remove) route from previous connection to public WIFI network using `nmcli` or `dhcpcd`?
Once I connected to public network then after awhile (1-2 hours) it won't give me access to internet. I assume this is because my routing is configured with previous IP given by DHCP of the public ...
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160 views
“iw wlan0 connect” doesn't works properly
i'm trying to connect an embedded linux distro, to my AP (named Validator_Test) that have no password configured.
iw wlan0 scan
works!
But if i type the following with root permissions:
iw wlan0 ...
0
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1answer
53 views
Debian Router Configuration Problem
I just got my brand new laptop and I intet to make the old one to act as a home router, just to play and learn a bit about Networking.
After I fallow some tutorials, I make the configuration as fallow:...
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76 views
KVM, qemu, libvirt no DHCP on bridge
After I restart firewall on the host machine, I no longer get DHCP on guests until I restart libvirtd.service
I am providing two network captures, one before restarting FW on the host (dhcp_ok.pcap) ...
1
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1answer
43 views
Is it possible for a dhclient-script exit hook script to hide a dhclient non-zero return code?
With dhclient, my understanding is that exit hooks in /etc/dhcp/dhclient-exit-hooks.d/* are sourced and run after dhclient completes. Because they are sourced, is there a chance that they could be ...
0
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1answer
120 views
dhclient OPENSSL_1_1_1
My dhcp client because some openssl version mismatch.
Here is an error:
debian:~$ sudo dhclient
dhclient: /usr/local/lib/libcrypto.so.1.1: version `OPENSSL_1_1_1' not found (required by /lib/x86_64-...
0
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1answer
109 views
How to configure DHCP server in Virtualbox CentOS7 VM for Cobbler PXE boot?
I am very new to Virtual Box and try to emulate cobber PXE boot network installation in virtual box
Trying to configure VM1 as PXE/DHCP server and make VM2 as client to get the IP from VM1 DHCP ...
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0answers
83 views
Debian Taking Too Many DHCP IPs
I have a Debian server (Stretch 9.9) that I recently noticed some odd behavior on; the default Ethernet interface (the only one aside from loopback) seems to be attempting to grab every available IP ...
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0answers
18 views
Manage identical dhcp servers
I have a weird problem that needs a solution. I have many identical DHCP Servers, configured the same way, same subnet, same range, same everything (are actually some PCs) and i would like to somehow ...
0
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2answers
42 views
Run command based on IP address received
I'm looking at if I can have a bash/python script that triggers a command based on the IP address Linux has received via DHCP.
e.g.
DHCP received: 10.50.10.51 /24 runs command XYZ
DHCP received: ...
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0answers
52 views
Is there a way to tell ISC KEA DHCP to always broadcast answers to clients?
I want to use ISC KEA DHCP v1.5 but I am not able to assign addresses to clients behind a wireless bridge. The reason for this is that KEA send sets the target IP address in the IP header to the ...
0
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1answer
34 views
get an ip automatic at direct connect
I have a raspberry pi with raspbian and on the eth0 port it is connected to my network and gets an ip address via dhcp.
But now I want to unplug the ethernet cable and just use a new one that ...
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0answers
647 views
Enabling DHCP for IPv6 in netplan with networkd doesn't seem to do anything
I'm currently configuring the network interfaces for a Ubuntu 18.04 server, using netplan with the networkd backend. My hosting provider provides me with an IPv4 and an IPv6 for this server, however ...
0
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1answer
69 views
How does the DHCP server sort the MAC addresses according to the physical order of the clients? [closed]
There are hundreds of servers, one of which serves as a DHCP server.
The hosts file of the DHCP server specifies the IP address and host name for each client server. But the MAC address of the client ...
2
votes
1answer
204 views
Prevent systemd-networkd (DHCP) from registering (NTP) time servers
I'm trying to stop some SBCs (running Debian) from updating their time via the router's own NTP server. We just want to use a manually configured one such as one from *.pool.ntp.org.
I believe the ...
0
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1answer
42 views
How to determine whether an IP adress is static or dynamic without root rights
On SUSE linux, I want to determine whether the IP address of the machine is assigned statically or dynamically without having root access to machine. What commands can I use for this purpose? What ...
0
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1answer
25 views
dhcp/named client identification issue
I am running CentoS 7.6 which has been configured as DNS server (via named) and a DHCP server.
In DHCP I have configured dynamic updates to my DNS zone such that new client leases will result in ...
0
votes
1answer
267 views
Switch between DHCP server and client on eth0
I am working with a arm micro-controller. Currently the controller is configured as a dhcp client on eth0 (ethernet jack) and as a dhcp server on eth1. I want to configure it to also serve dhcp on ...
2
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0answers
754 views
PXE Boot: “Failed to load ldlinux.c32”
I'm trying to create a PXE server on my raspberry pi, but if I try to boot, the client shows the Error "Failed to load ldlinux.c32". This is my folder structure of the tftp folder:
Here is my ...
0
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1answer
440 views
dhclient is not getting an lease / ip address from dhcp - but windows gets one
How could it be that I get easily an ip address with Windows 10 network manager and not with simple Linux QNAP NAS System?
And not working situation.
I tried to renew the ip address manually.
[...
1
vote
1answer
66 views
ssh, trust hosts on fingerprint basis only, regardless of IP
In ssh configuration directory, the file known_hosts stores for each server the (IP, fingerprint) couple. A server is trusted only if it matches both the elements of one of the couples in known_hosts.
...
3
votes
2answers
475 views
Debian workaround 838871: dhcp network configuration without blocking boot process
Is there a workaround for Debian Bug #838871?
Problem: I want to have a network configuration on Debian with the following properties:
Automatically ifup network interface when a cable is plugged in
...
0
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0answers
1k views
How to set up functional private network bridge on qemu/kvm?
System
My host is running Fedora 29, and my internet connection is wifi. Note that I am using X.org, not wayland; the SDL option in qemu doesn't work on wayland, and the curses option has trouble ...
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0answers
212 views
Modifying U-boot booting script and DHCP command script in Petalinux
I want to try the following things :
Modify the booting arguments of u-boot of my Petalinux project which is currently using the Xilinx Kernel. I want to modify it such that it runs DHCP during ...
3
votes
0answers
68 views
Why is my client getting two IP addresses when connecting to WiFi?
A sub-question: why is my client requesting a specific IP address without a dhclient running?
I have two access points. One is serving up two SSIDs, the other just one SSID. When I connect to the two-...
1
vote
1answer
38 views
No internet connection with some routers
On my laptop I run Debian Testing with no Desktop Environment.
I manage the Wifi connections by adding entries to /etc/network/interfaces and then running /etc/init.d/networking restart.
dmesg says:
...
0
votes
1answer
50 views
How to set an IP from a specific range with dhcp?
I want to set a IP to my Debian machine using dhcp but I only want to select that IP from a specific range .
For example, my net is 10.0.100.0/24 and the range has to be from 10.0.100.90 to 10.0.100....
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0answers
20 views
Running under systemd changes networking how?
For obscure reasons, I started a docker container from systemd. This container has a DHCP server in it.
I ran nmap -e eth0 --script=broadcast-dhcp-discover.nse from the command line outside of any ...
0
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1answer
28 views
How to allow certain IP's accessing an IP:Port range?
So I have an ESXi server setup with pfSense acting as the DHCP Server for the VM's. I use VNC's to access each VM over the internet (For example with ports :5905,5906,5907 etc.) and I would like to ...
0
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0answers
17 views
Different Wi-Fi SSIDs, same network: cannot switch connections
I have a small network at my home, where the main Internet point stays at the living room, with two signals, a 2.4G and 5G, on the same network. Also, I have a Ethernet over Powerline link to my ...
0
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1answer
99 views
Does netmask and option subnet-mask have to be equal on a dhcpd.conf definition?
Using linux servers on a dhcpd.conf file I can make a definition of ip ranges that the server will assign to host computers on the internal net:
subnet 10.0.0.1 netmask 255.255.255.0 {
range 10.0.0....
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2answers
670 views
NetworkManager interferes with hostname configuration
I'm running an arch system with KDE4/Plasma, wpa_supplicant, networkmanager, systemd ...
# cat /proc/version
Linux version 5.0.0-arch1-1-ARCH (builduser@heftig-18825) (gcc version 8.2.1 20181127 (...
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42 views
How to get DHCP info from DHCP Client to DHCP Server
I have a firewall with an Internet-facing ethernet, and a home LAN facing ethernet. The Internet-facing interface acquires DNS server ip addresses from the ISP's DHCP server. I would like to propagate ...
