Questions tagged [dhcp-server]
Dynamic Host Configuration Protocol (DHCP)
542
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isc-dhcp-server fails if interface not connected on reboot
On Ubuntu 18.04 on my gateway server, I've installed and configured isc-dhcp-server, but it doesn't start up (i.e. it fails to start) if there's nothing connected to enp2s0 after a reboot.
Note it ...
2
votes
2
answers
2k
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How to fix DHCP server after main switch replacement
I am a computer science teacher in a small school who is getting to grips with a role as server/network admin. Today, we all lost internet connection and were unable to access the server remotely.
It ...
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0
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1k
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DHCP server ignoring DHCP requests
My DHCP server is ignoring DHCP request from specific client. Using tcpdump in my host controller (where DHCP is served from) I can see the requests
21:50:12.909484 IP (tos 0x0, ttl 255, id 1319, ...
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1
answer
6k
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Windows Server 2016 Dhcp failover configuration
I've built a new AD domain and I've got 2 dhcp servers (2016 & 2019) that have been setup in a Failover partnership. I've tested it and it's working correctly. I decided to RENAME both of these ...
0
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1
answer
104
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intermittent wifi/LAN client connection issues with dhcpd and bind9 on ubuntu server
I have a soho LAN with a gateway server running isc-dhcpd-server and bind9 on one NIC 192.168.0.3 for the LAN & wifi.
The client connects to the LAN but often can't see the server on 192.168.0.3 ...
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0
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63
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DHCP, DNS, DC on single VM
I'm trying to install simple scheme of server:
Hype-V as host
DNS, DHCP, DC on single VM.
However I've got difficulties with make my DHCP server work - client devices got IPs only from my MikroTik ...
0
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2
answers
1k
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AD/DC, DNS and DHCP on Hyper-V host
I'm trying to set up AD/DC with DNS (reverse lookup zone) and DHCP on single Hyper-V host. Network diagram
On the diagram is pretty everything I've set, the rest should be on default, however I'm ...
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1k
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WDS and DHCP on different server to provide pxe boot
I have two standalone windows server 2016 which configured with WDS and DHCP respectively, and they are located in the same VLAN broadcast domain. I want them to provide PXE boot for client machines ...
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1
answer
3k
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move DHCP service to another windows server seamlessly?
i've searched similar answers on serverfault and google but i need to clarify the procedure to do this.
i have a old windows server 2012 which provides dhcp service and now want to transfer this dhcp ...
1
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2
answers
435
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Using DHCP to Manage Servers
There is a thread from about 9 years ago that I was reading when looking into whether we should change the servers in our environment to DHCP.
Here is the Link.
DHCP addressing vs Static ...
1
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1
answer
16k
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Force client to send DHCP options to next-server
We currently have clients connecting to a DHCP server when asking for an IP. We then redirect to next-server with some additional options.
The next server has a DNSMASQ running that should be able to ...
1
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1
answer
6k
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Windows Server DHCP not working
I have an Active Directory network consisting of a Windows server 2019 domain controller with DHCP and DNS on it too. New clients on our network are failing to obtain IP Addresses from the DHCP server,...
1
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1
answer
3k
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DNS server information not provided to DHCP clients by dnsmasq
I am trying to utilize a Raspberry Pi with Raspbian Stretch (Linux) so provide additional network monitoring and also routing capabilities. To this end I have the following setup:
Internet router [...
0
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1
answer
544
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windows deployment services to windows 10
I am currently in Computer Assisted Tech training I have difficulties for the image deployment service.
I want to deploy a Windows 10 image on HP Pro Book 650G1.
I have a Windows 10 Pro x64
For this ...
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2
answers
3k
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How to serve custom DNS server to DHCPv6 clients in OpenWRT?
How to serve custom dns to dhcp clients in openWrt? explains how to serve custom DNS server for DHCP clients on IPv4.
But how to do it for IPv6? I tried adding DNS server's IPv6 address but it doesn'...
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0
answers
226
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DHCP Server shutting down?
I have a Server 2012 R2 Essentials server, which is the PDC in the domain. I also have another 2012 R2 server acting as a domain controller for times when the primary is down.
I have setup DHCP on ...
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2
answers
572
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DHCP Server stopped working
I've been searching all day long, but nothing helped so far.
Computers without lease can't connect to the network. Everybody else who has an active lease doesn't have any problem.
We use DHCP Server ...
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1
answer
1k
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How can I make the Domain Controller the client's default gateway?
I'm migrating from a SBS 2008 DC to a Windows Server 2016 DC. On the SBS DC, DHCP is set up and I've migrated this successfully to Server 2016. The PC's in the office use the SBS DC as their default ...
2
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0
answers
984
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Clear routes from DHCP option 121
I have 3 subnets
192.168.10.0/24
192.168.103.0/24
192.168.2.0/24
Most of them can route to each other via static routes defined in their respective default gateways.
However due to some ...
0
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0
answers
160
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Cannot add DHCPv6 reservation on Server 2012 R2 (error 20022)
I am trying to add DHCPv6 reservations on a Windows Server 2012 R2, but I do not want to use the "random" IPv6 the server chose (convert lease to reservation), but I want to use another, specific IPv6....
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2
answers
2k
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vlan for segmentation, same subnet one dhcp server
I do not know if this is the correct setup.
I need to isolate three ports on three different switches from the other ports (update: so they are separated from the others and also have access to the ...
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1
answer
38
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Does it make sense to have several subnets under a ethernet port for a dhcp configuration?
I would like to know if it makes sense to set several subnets under a ethernet port. The configuration on dhcpd.conf is listed below:
subnet 192.168.10.0 netmask 255.255.255.0 {
#ethernet port ...
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1
answer
378
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How can I find (or compute) a client MAC address when using the strongSwan DHCP plugin?
Server strongswan.conf
libtls {
suites = TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
}
charon {
plugins {
dhcp {
# Always use the configured server address.
force_server_address = yes
...
1
vote
1
answer
406
views
Offline Windows DHCP
My company is needing to switch over from our current DHCP server to building out a new virtual machine Windows 2016/2019 DHCP server.
The question I have is, can I build the server and configure ...
0
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1
answer
141
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Pfsense networking, routing and rules
I'm new to pfsense I just installed it today. I'm trying to configure a DHCP server. I have three interfaces the WAN, LAN and Guest Network. I configure the LAN to 192.168.0.1/20 and the WAN is DHCP ...
1
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1
answer
212
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Isc Dhcp-allow only 1 lease from opt82 tag
I'm implementing an isc dhcp server that will be utilizing option 82 tags from our switches to hand out dhcp information/addresses I'd like to deny multiple requests with the same tag (if someone ...
2
votes
1
answer
3k
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UEFI Enabled; unable to get IP address from DHCP, WDS
I'm trying to boot PCs from a Windows 2012R2 WDS server in UEFI mode. it works fine BIOS mode, but I want to boot from UEFI mode.
I have change the boot setting to UEFI mode; secure boot in BIOS.
I ...
0
votes
1
answer
56
views
How to scan for (erroneous) static IP configurations within DHCP server scope
How can I scan for any statically configured IP addresses in use, within a Windows Server DHCP scope, of which the DHCP server is not aware?
I'm dealing with a network I inherited on which I found ...
1
vote
1
answer
594
views
Switching from Linux DHCP Server to Windows Server DHCP
We are using a DHCP server out of a linux OS right now for our subnet. I am thinking of changing to a Windows DHCP Server, however, because it might be easier for future admins.
What I want to do is ...
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1
answer
529
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How many addresses can be assigned to one network interface via DHCP
Are there any limits to how many addresses can be assigned to one client DHCP host from DHCP server?
Can I assign whole /8 subnet to one interface via DHCP?
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0
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DHCP Leases (8 days) expiring more than once a day. (Windows Server DHCP)
First of all, I'm sorry if I'm posting this to the wrong place. I'm new here so I am still getting used to how the site works!
We have a DHCP server and the scope lease is set to 8 days, but we found ...
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1
answer
2k
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Softether VPN - How to setup Squid proxy without switching off SecureNAT DHCP?
I have a Softether VPN server running and configured to use DHCP (SecureNAT) instead of local bridging as I couldn't figure out how to do it (despite reading all available tutorials on the internet). ...
2
votes
2
answers
210
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Unable to add two scopes?
I am trying to add two scopes of different range say (192.168.0.5-192.168.0.10), (192.168.0.15-192.168.0.25) on windows DHCP server while I am trying to add the second scope it says the address range ...
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1
answer
1k
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Ubuntu 18.04 DHCP server can't pass its DHCPOFFER to clients (endless DHCPDISCOVER/DHCPOFFER loop)
I noticed that on Ubuntu 18.04.1 DHCP server (isc-dhcp-server) always responds (DHCPOFFER) directly to the IP it offers to the host having sent DHCPDISCOVER.
The DHCPDISCOVER packet has its Broadcast ...
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2
answers
2k
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Why does my Windows DHCP server hand out a non-configured subnet mask?
We run the DHCP server role on our domain controller (Windows SBS 2011).
We want our LAN subnet to be restricted 10.1.1.0/24 (unsure if this is the correct notation but our subnet to be restricted ...
2
votes
2
answers
3k
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DHCP not sharing Internet access
I have several Virtual Machines in Vmware ESXi 6.5 with 2 Network Groups.
Created a DHCP Server Machine on CentOs with 2 networks interface.
1 / vm network from which it takes a network and has IP ...
1
vote
0
answers
360
views
Is the latest dhcp spec (rfc4361) invisable to admins?
When having an old Winsdows 2003 dhcp server, which doesn't understand the dhcp identifier OS'es such as Fedora 29 and Ubuntu 18.04 server sends. Which looks like
10,11/09/18,12:28:17,Assign,192.168....
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1
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721
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Exclude subnets from distribution?
In Windows' DHCP server it is possible to exclude an entire subnet from being given out to clients which doesn't have a reservation. They call this "IP addresses excluded from distribution".
Now I ...
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1
answer
4k
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DHCP in Azure in case of fail in Onprem [closed]
Please confirm can we install DHCP server in Azure. Actually, we want to use this Azure DHCP in case of DHCP fail in Onprem.
Please confirm how can we enable the same IP addresses in the Azure by ...
1
vote
1
answer
3k
views
Dynamic DNS client records not being updated correctly
Our network is running Windows and macOS clients all of which are joined to Active Directory. The Macs are all running Windows via Bootcamp. We were having issues which were being caused by our macOS ...
2
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0
answers
640
views
Weird answer of linux DHCP server to gratitious ARP causes DHCP failure
This is a problem, that I ran into recently on a quite heavily configured linux server. This machine runs Samba as an Active Directory Domain Controller, a mail server, a web server, two virtual ...
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1
answer
1k
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Why would ISC dhcpd ignore vendor options?
I'm trying to use an existing dhcpd to autoconfigure Raritan networked PDUs. This works roughly like PXE booting: there are additional DHCP options that direct the device to fetch a config file via ...
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0
answers
1k
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How do you keep Windows from changing DHCP Reservation Names
It is a SBS-2011 Server. I will create a new DHCP reservation and set the reservation name to "GSMPC-11 N". Then it looks like when it goes active Windows changes the name to the computername.domain i....
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2
answers
2k
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Two DHCP servers giving static addresses in a network
I have a network having two servers that are occasionally booted. I wish to maintain DHCP services even during a boot of one server.
One of the servers currently has a DHCP server that gives static ...
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2
answers
1k
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Disabled dhcp-server on router prevents clients from getting an address
I have a weird issue on my local network which prevents some clients, sometimes acquiring an ip address from the real dhcp-server (x.x.x.3). The dhcp-server is a CentOS VM running isc-dhcp-server for ...
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1
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14k
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Setting up pfSense to bridge LAN NICs and connect WAN
I have a machine with four NICs (physical ethernet ports) and I'd like to set up a fully updated pfSense on it. So far it looks like this:
A few things I've done so far:
I've set up the bridge ("...
4
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1
answer
414
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Why is this checkbox disabled in Windows DHCP server range policy / vendor class management?
I manage several Windows 2012 based DHCP servers and on one of these I came across a peculiarity that I cannot explain and do not know where to correct:
In DHCP manager*, expand [server name], then ...
0
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1
answer
620
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Have freeRadius/Linuxcooperate with DHCP-Server/Windows
We have freeRadius for authentication on a Ubuntu box, but the DHCP allocation is handled elsewhere, specifically by a Win2012R2 DHCP server. Is it possible to configure freeRadius in such a way that ...
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1
answer
10k
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How to reserve a static-ip on Mikrotik router for a device that is attached to a fixed router's Ethernet port
I am trying hard to figure out how can I force any DHCP client device connects to the port ETH10 on Mikrotik router get assigned a fixed IP-address.
Please note that the device MAC address is unknown ...
0
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1
answer
141
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How to configure second wireless router via VLAN trunk? [closed]
I am trying to figure how to configure the second wireless router, but I got stuck while trying to get the following configuration:
For all VLANs (0-3), the primary router is the DHCP server for IPv4 ...