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.
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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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How to get DHCP from other bands of DHCP server without DHCP relay package
This is the topology that I want to make of.
User gets DHCP from ex-ns, but can't use any packages on router such as isc-dhcp-relay, dnsmasq, dhcp-help, etc. I think it should use things like iptables ...
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why can the dhcpcd service not be found and run on raspiOS? [closed]
I'm trying to set a static IP for my raspi, and I am using the document /etc/dhcpcd.conf. This document currently looks like this:
interface eth0
static ip_address=192.168.1.115/24
static routers=192....
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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 ...
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Internet failover on Cisco ASA 5500 series Primary ISP is on DHCP address and so is backup. Always defaults to backup
I had SLA MONITOR setup on my ASA and working fine for months. All traffic was routing through my primary connection. I rebooted my ASA after a firmware upgrade.
When it came back, it would always ...
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Mikrotik DHCP client variables for option 82
It is possible to add the DHCP option 82 in DHCP client of mikrotik router?
mikrotik default DHCP options
I want to add the Agent-Circuit-ID and Agent-Remote-ID from DHCP client option of mikrotik ...
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pfSense L2 firewall not blocking half of DHCP traffic
I have a pfSense instance (NetGate SG-series), with setup:
802.11q enabled
LAN ports 1 (LANP) and 2 (LANB) with VLAN assignments
Interfaces assigned and enabled
LANP:
(1, 5t) tag configuration
...
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VLANs with ESXi over physical switch
I'm trying to setup a VLAN across my ESXi network and my physical switch network, but fail to get the VMs on the ESXi port group communicate with physical network. Specifically, my VM doesn't see ...
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Server lost network connection while dhcp server messages log shows abandoning ip address pinged before offer
Some of my servers lost network connection (ip address disappears in ifconfig). I checked the linux dhcp server's messages log, and I found around the time those servers lost connections, there are ...
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Intermittent workstations with no network connectivity
I have a campus wide network with ~10 workstations around campus(not from the same switch) that can't connect to the internet/network, they are successfully acquiring an IP address from the DHCP ...
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Getting IP address from another subnet's DHCP
As in the diagram below I have two routers on two different subnets.
I connected them together but have not set static routes yet.
Network Diagram
However, when connecting from Access Point A's SSID, ...
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Bind DHCP Config with LDAP Database without DHCP-ISC
I want to get my DHCP Config from LDAP-Database. Especially the subnet hosts should be migrated there. However, I don't find a lot of information about this procedure. Is it not recommended? I ...
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DHCP renewal can't go through because DHCP server is down
To my experience, if a DHCP client tries to renew its lease, but the DHCP server is down, and after the lease time is over, there are two possible scenarios:
The client keeps the IP
The client goes ...
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DHCP response not getting to VM when using a VLAN on Proxmox
I recently installed proxmox on my server, and now I'm trying to get networking in order.
The problem that I have, is that for a certain VLAN, the DHCP response from my DHCP server doesn't seem to end ...
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Servers network connection lost in an arbitrary fashion
I have about 300 server nodes using PXE boot process and with dhcp ip. Those 300 nodes communicate with a "central" server that is served as the PXE server and dhcp server. However those ...
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How does the variable "pxe_default_server" get set in Red Hat 7.9?
We have a RHEL 7.9 server that is acting as a DHCP/TFTP (PXE) server servicing multiple subnets. Below is a copy of our dhcpd.conf file (the DHCP/PXE server is X.Y.145.98):
allow bootp;
allow booting;
...
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netplan parents inteface of vlan has dhcp. i want to disable
i use netplan to assign ip address with vlan on my ubuntu 22.02.
i disabled dhcp for enp2s0 which is parent of my vlan.20.
But It has dhcp random ip addresse. I want to disable. how to do this?
$ cat /...
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Untangle NG Firewall DHCP options based on MAC address / IP address?
We are trying to set DHCP options based on IP address.
Scenario: We have 50 systems in network and want to configure some systems with google DNS and other systems with internal DNS.
I tried below ...
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Making all Linux network interface (bridged) in a qemu VM use dhcp
I have a small application which takes in kernel code, and spins up VMs. I've been using this for kernel development. It is helpful and very fast when I want to spin up VMs with different kernel codes....
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Iptables rule to capture DHCP I/O fails
I have stumbled upon a peculiar issue with Iptables. I am not seeking a solution to a problem, but an explanation of some strange behaviour of iptables.
My platform is Ubuntu 22.04.2 LTS with 5.19.0-...
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DNS Suffix List is getting weird on Windows Server 2022
I had a look on my Windows Server 2022 template and figure out the following things:
If I run ipconfig /all, i can see there's 'test.local' as Global Suffix Search List and there's gael-test.net as ...
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Dual dnsmasq name resolution
For resilience, I have two dnsmasq instances providing both local DNS and DHCP. DHCP is configured to offer separate IP ranges from each instance.
I then add IP reservations to the /etc/dnsmasq.d/99-...
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IPV6: Linux-Clients does not register Hostnames via DDNS
I have a problem to get Hostnames registered in DNS (Windows AD DNS-Server) when they request a IPV6 (NA). While IPV4 gets fine i can see in syslog an "added reverse and added forward mapping&...
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What is Option 60 (Vendor Class Identifier) used for in DHCPv4?
Currently I'm using Wireshark to analyze the DHCP process between wireless devices and my DHCP server (which in this case, is my Wi-Fi router).
On all of the devices that I tested, I noticed that each ...
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dnsmasq DHCP server not responding
I have connected a HikVision camera to a raspberry pi through two ethernet power line adapters TP-Link TL-PA4010.
I have configured the eth0 interface of the raspberry to have a static ip address. In /...
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Applying initcwn/ initrwnd to routes from DHCP
I am using Amazon Linux 2023 (which is based on Fedora and uses systemd-networkd for DHCP).
ip route show shows routes like default via 10.0.0.1 dev enX0 proto dhcp src 10.0.0.211 metric 1024
I would ...
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Azure DHCP Options
It appears that Azure doesn't provide many DHCP options for new VMs. On a new client, I looked at the registry entry HKLM/System/ControlSet001/Services/TCPIP/Parameters/Interfaces and found only these ...
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Reserve IP based on DHCP Option 61 insted of MAC Address
a DHCP client is sending a discovery packet with option 61. Now the Windows server 2019 /2022 needs to respond with the offer based on the DHCP reservation, reservation is registered based on option ...
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How does vSphere DHCP assign IP addresses?
I have installed Ubuntu in a vSphere VM and due to some error, it got the wrong IP address. I asked IT to fix the DHCP entry and they did but the VM kept getting assigned the wrong IP. I could get it ...
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DHCP server does not provide correct filename for PXE
I'm trying to configure PXE server for both Legacy/UEFI support. So I need to provide different bootloaders based on architecture of machine.
Here's part of dhcpd.conf:
option architecture-type code ...
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DHCP Renew vs rebind timers
Windows DHCP, FortiGate relay. No rule that allows for direct renew from PC -> DHCP serwer that gave the IP. 20 minutes expiration timer, 10 for renew, 17.30 for rebind.
What happens:
After 10 ...
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Can I have a single DHCP server with Multiple NICS [duplicate]
My question is on the feasibility of having a single DHCP server with 2 NICS, each NIC connected to an independent network. Each independent network will have an IP helper configured pointing to the ...
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Difference in routing between systemd-networkd and dhcpcd?
When using systemd-networkd with the configuration below, I cannot connect over SSH (connection time out) to a certain server on our network. Bizarrely, there are no problems when I use dhcpcd instead....
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Windows DHCP IOT retain same IP
I am trying to address a problem.
We have a windows DHCP server and some devices, which we need to replace on needs. The device has a custom DHCP client which sends DHCP-DISCOVERY Packet with ...
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Manage UniFi DHCP reservations on UDM via shell
I'd like to be able to manage DHCP reservations on my Ubiquiti Dream Machine (UDM) directly via shell. I've tried to locate dhcpd or dnsmasq configuration files that can be edited and persist through ...
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Configuring DHCP Split Scope via PowerShell
In Windows Server DHCP console (GUI), having two servers available, it is simple enough to "Split-Scope" and create an 80/20 situation:
Right-click over any scope on the first server (of two)...
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Forcing static IP on libvirt
I've seen this question and others online, yet my problem persists.
I have a gentoo host with the following interface:
virbr0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet ...
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How do you get docker to work in amazon vpc? (ip assignment coordination)
Is there a way to block out a range of ips in the VPC?
Alternatively is there a way to get docker (docker compose) to use dhcp to get ip addresses? If it does so will they be blocked from being ...
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dnsmasq not resolving hosts properly
Using DD-WRT, dnsmasq seems to be failing to correctly resolve hosts, and I can not understand why.
root@gcs:~# cat /etc/resolv.conf
nameserver 192.168.1.1
root@gcs:~# cat /tmp/dnsmasq.conf
...
dhcp-...
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Periodic Disconnection with DHCP DISCOVER
LAYOUT
192.168.0.103(THE ONE LOSES THE CONNECTION - WIRESHARK CAPTURE)
192.168.0.84(THE ONE WORKS PROPERLY - WIRESHARK CAPTURE)
We have an app that receives data from one of our devices. We installed ...
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Same FQDN for different IP depending on connection
I run a Kerberos / LDAP user authentication on Debian, which works nicely for decades. I now would like to use notebooks, which may connect by wire or by WiFi. I'm stuck thinking how to set up this ...
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How to configure dnsmasq per interface nameservers from DHCP leases
I am working on an IoT device that has three network interfaces: Ethernet, WiFi, and LTE. The interfaces provide redundancy and fail-over for network connectivity, and any combination of the ...
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Managed switch filters unicast DHCPOFFERs, but allows broadcast DHCPOFFERs?
I have a network containing N managed switches. Each of them is configured as a DHCP server and should assign predefined IP addresses in a port-based manner:
Switch 1 assigns 172.17.1.1 to the device ...
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PXE with proxyDHCP server: What makes a DHCP client accept / ignore offers from primary DHCP?
I am considering a setup with a primary DHCP server providing "IP data" (IP address, subnet mask, DNS, …), and a proxyDHCP server providing only PXE boot options. As it happens, my proxyDHCP ...
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Migration strategy to migrate a DHCP scope from old DHCP server to new DHCP server as smooth as possible
My current homeLab and entire home is currently running on a single subnet 192.168.0.0/24 with my ISP provided router running a DHCP scope handing out addresses in the 192.168.0.20-192.168.0.254 range,...
