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.
510
questions with no upvoted or accepted answers
6
votes
0
answers
7k
views
Debian 10 Buster can't renew DHCP as client, when IPv6 is disabled
After I upgraded Debian 9 to 10 Buster server lost network connection after 24 hours since reboot, I think problem is it can't renew IP address from DHCP server.
In /var/lib/dhcp I see the file ...
6
votes
0
answers
6k
views
DHCP Server Not Offering to PXE Client
DHCP Server Not Offering to PXE Client
BACKGROUND:
I'm in the process of adding PXE services to an existing SCCM 2007 server. The SCCM server is separate from the DHCP server (Server 2008 x86) and ...
5
votes
0
answers
3k
views
BIND: DNS failover and high availability with dynamic updates
I am trying to design a system with 2 servers that act as both DHCP and DNS servers with dynamic updates. I am using ISC DHCP and BIND9.
It looks like this.
Server1 - DHCP primary and DNS master. IP ...
5
votes
0
answers
10k
views
How can I identify a rogue IPv6 DHCP server on my LAN?
This will be kind of a long post, but I want to give complete information.
I have a home/business LAN with isc-dhcp-server running an ipv4 dhcp server and bind as a DNS server running on an ubuntu ...
4
votes
0
answers
7k
views
Windows DHCP Server not responding to relay requests
I have a Windows Server 2016 (Datacenter Core) running DHCP server role which is not responding to DHCP requests which come from a DHCP relay but is responding to DHCP requests on the local network.
...
4
votes
0
answers
567
views
DHCP Server Listing Host as "BAD_ADDRESS" and not Registering DNS
Question
Why is DHCP showing "BAD_ADDR", why does it think there is a Conflict, and why can't the host register its DNS name?
Devices:
DHCP Server = Server 2012 on bare metal. Also running DNS.
...
4
votes
0
answers
773
views
Cannot renew DHCPV6 lease in SLES12
I need to renew the lease of a certain SLES12 box. The machine is configured to use IPv6 only and so far I have tried the following:
From here:
dhclient6 -r -v eth0 && rm /var/lib/dhcp6/...
4
votes
0
answers
3k
views
VLAN ID over DHCP for Management Interface of Fortinet FortiAP
When configuring the FortiAP device it's desirable to configure the VLAN ID for the tagged management network. Accordingly to the manual it's possible to do so by "telnetting" to the FortiAP device ...
4
votes
2
answers
2k
views
Prevent Windows Server 2012 from using DHCP-provided default gateway?
How can I prevent Windows Server 2012's local network connection from using the default gateway provided by a DHCP server? I do not control the DHCP server so the solution must be implemented on the ...
4
votes
0
answers
663
views
DHCP fault tolerant servers: Split pool or failover?
I need to replace an aging DHCP server by a fault tolerant solution. I consider using the ISC dhcp server solution which can be setup either as split servers serving non-overlapping ip ranges or as a ...
4
votes
0
answers
4k
views
vmware DNS in host-only configuration
I want to connect a Linux VM running in VMWare on a Windows 7 laptop to an enterprise network using host-only configuration.
I was able to setup bidirectional routing between "host-only" VMWare ...
4
votes
0
answers
4k
views
Windows 7. DHCP option 121 works partially. But it working fine for XP and Mac OS X
I've setup pptp server on cisco router today. The remote client IP addresses are assigned on this cisco router by DHCP. Also I set up option 249 and 121 to provide classless routing for my VPN clients....
3
votes
0
answers
2k
views
dnsmasq: How to set alias domain / multiple DNS suffixes for local hostname resolution?
Is it possible to set multiple search domains via dnsmasq/DHCP? Due to some migration, I need multiple clients to be able to:
ping server.old-domain
ping server.new-domain
# both should work, .old-...
3
votes
2
answers
5k
views
Is it possible to have name-resolution from Fortigate and local DNS server?
Can you advise on moving to a hybrid DNS?
Currently, all our LAN machines receive their IP address from our Fortigate 60D (each machine is either allocated an IP address from the Fortigate DHCP, or ...
3
votes
0
answers
2k
views
DHCP Server not responding to relayed DHCP DISCOVER
I'm currently segmenting our network in various subnets. We already have a DHCP server as a part of our Active Directory (Server 2012). I want to use this server for all subnets so I need to work with ...
3
votes
1
answer
971
views
Search option in resolv.conf getting overwritten by prepend statement in dhclient.conf
I have setup a DNS server for my department which is running FreeBSD 10.2. It is currently connected to the campus internet and receiving its address via dhcp, so /etc/resolv.conf looks like this:
#...
3
votes
0
answers
201
views
Did I cause this DHCP failure?
I asked this here, it was requested that I move it to this forum instead.
I have a question that I need some counsel on concerning DHCP and what may happen in a certain situation.
I have a case ...
3
votes
0
answers
2k
views
Assign a public ip to openvpn client
For learning purposes, I'm trying to set up openvpn server, so that each connected client would get a unique public ip address.
I have a vps server and I ordered extra 8 static ips and they are ...
3
votes
1
answer
345
views
How did AirPort's DHCP "Welcome Message" work?
I remember that Apple's AirPort base stations used to have a DHCP "Welcome Message" feature, that would display a custom pop-up dialog when computers connected to the network. How was this ...
3
votes
1
answer
257
views
Reaching out DHCP relayed hosts
I have one primary server (DHCP) and one secondary (DHCP-RELAY).
Majority of hosts are served from primary (wirelessly), however there are a few (wired ones) which get their IPs from secondary.
...
3
votes
0
answers
913
views
ISC DHCPD IPv6 for multiple interfaces
I want to assign multiple IPv6 to a server with multiple NIC.
As IPv6 RFC defines, each server has a unique DUID that can have one of the 3 formats (LL, LLT or enterprise). And each NIC has an IAID. ...
3
votes
1
answer
3k
views
DHCP Server Issuing NAK when servicing multiple subnets
We currently have 3 VLANs setup in our network. On our DHCP server (Windows 2008) we have 3 scopes created for the 3 separate subnets. Our clients can't seem to pull addresses on the subnets, except ...
3
votes
0
answers
2k
views
How to config libvirt network setting about disabling dnsmasq "except-interface=lo"?
Here is the thing.
My VMs run with libvirt and use default network libvirt-provide, and I've mad each VM registers its hostname to dnsmasq set by libvirt. so I want to look up its hostname for ...
3
votes
1
answer
3k
views
Client see Windows Deployment Services but still get "selected boot device failed" error
Like the title says I can't Windows Deployment Services working. The client laptop has an ethernet IP address of 10.0.4.94. On the secondary DHCP server I've set option 60 to PXEClient, option 66 to ...
3
votes
1
answer
7k
views
Use Framed-IP-Address RADIUS attribute for IP allocation with DHCP on Windows Server 2012R2
I have configured a DHCP server on Windows Server with an NPS Policy, connected to a FreeRADIUS2 server running on pfSense.
Authentication is based on MAC address. If MAC address is not present in ...
2
votes
0
answers
136
views
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 ...
2
votes
0
answers
210
views
NTP Server Precedence using systemd-timesyncd
I'm looking for documentation which specifies the precedence / priority of NTP servers (ubuntu 20.04).
I am using timesyncd which has the ntp.ubuntu server
But when connecting to the network via DHCP ...
2
votes
0
answers
2k
views
Why is my systemd-networkd not aquiring an IP address via DHCP?
On my notebook running Gentoo, I set up the following things:
Kernel with all necessary settings and modules
WPA_Supplicant
Systemd
Systemd-Networkd
Almost everything works as expected, the ...
2
votes
0
answers
323
views
DHCP searching wrong network
I have a stand-alone device with no console. It's searching for DHCP address on 192.168.1.1/24 while my network router serves DHCP for 192.168.0.1/24. Thus, the device is not getting assigned an IP ...
2
votes
0
answers
3k
views
dnsmasq dhcp ignoring dhcp-host definitions
I am currently puzzled by the dnsmasq configuration, and I hope someone here can help me...
I've setup successfully the DHCP-Server with dnsmasq, and I've tried to include some static Host ...
2
votes
0
answers
275
views
Request an address from a range of IP-addresses using dhclient dhcp-requested-address
I am in a situation where I need myDevice (ubuntu), when connected to router, to have any IP address in the range of 192.168.1.20 to 192.168.1.40. I am aware that adding the line
send dhcp-...
2
votes
0
answers
135
views
DCHP server on virtual machine in HNVv1 virtual network
I've got a virtual machine with Windows Server 2016 Datacenter, Hyper-V nested virtualization on the host operating system switched on for this virtual machine and Hyper-V role installed on it.
PS C:\...
2
votes
0
answers
3k
views
Dynamic DNS (DDNS) updates from dnsmasq for use with bind9
Previously I ran dnsmasq on an OpenWRT to provide DNS and DHCP functionality, because this is, what it is intended for. I want to offload the DNS part to an already configured bind9 (running on Ubuntu)...
2
votes
0
answers
984
views
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 ...
2
votes
0
answers
536
views
DHCP client doesn't get address
I'm trying to use a Phytron MCC-1 motor controller which gets its IP only via DHCP (no manual setting). I setup isc-dhcp-server on ubuntu as such:
# /etc/dhcp/dhcpd.conf
option domain-name "example....
2
votes
1
answer
289
views
How to share VPN and DHCP server across multiple hosts?
I need to set up a small computer network for what is effectively a satellite office for a business. The small network consists of several workstations and a server. The server machine has two ...
2
votes
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 ...
2
votes
0
answers
3k
views
DHCP Server: Missing Addresses and how to free them
Our DHCP Server, running on a Windows Server 2012 R2 Data Center, shows that we have 241 addresses total with 220 (91%) in use, 21 available. If I go to the Address Leases node and count all IP ...
2
votes
0
answers
538
views
Docker: Assigning IPs to containers using a DHCP server
I want to get docker to assign IPs to my containers using a DHCP server, so that they are kind of static based on MACs. From my preliminary research, it looks like I can use macvlan networks to create ...
2
votes
0
answers
1k
views
How to configure QEMU DHCP and DNS for VMs?
I am trying to configure a QEMU setup with several VMs that talk to each other (e.g. a LDAP server on a VM that provides SSH authentication to other internal VMs).
All these VMs are user mode and ...
2
votes
0
answers
164
views
ISC DHCP (Infoblox) takes 30+ seconds to respond to DISCOVERS
Client's DISCOVER packets reach the Infoblox DHCP server through DHCP relays, but Infoblox doesn't seem to be responding.
I checked the pcap taken from the DHCP server, I can see there is 3 DISCOVERS ...
2
votes
0
answers
141
views
Fedora 26 graphical login starts before network fully running
I am creating a Fedora 26 image that is going to run on around 100 machines in a closed environment. These machines will be connecting to two servers, one for NFS, the other for web services. The web ...
2
votes
0
answers
1k
views
How to configure Juniper SSG5 with VLANs and DHCP
I just purchased a used SSG5, upgraded the firmware, and now I'd like to set it up as my Firewall/DHCP/VPN. I'm new to Juniper, so please forgive any blatant missteps in terminology.
I am familiar ...
2
votes
1
answer
1k
views
DHCP server is not selecting IPs inside of the specified range
I have my DHCP server which I specificaly set the ip range to be between: 10.53.70.100 -- 10.53.70.200 but there are sometimes I get IPs outside from this range. For example, the last server I created ...
2
votes
0
answers
466
views
Does "broadcast-address" needs to be within defined subnet in dhcpd.conf?
Ideally, broadcast address should be last address of defined subnet.But I don't see dhcp server enforces such restriction.A brodcast-address defined outside subnet in dhcpd.conf is accepted by dhcp ...
2
votes
2
answers
1k
views
Why does my Ubuntu virtual machine hosted in Hyper-V power on with a date in the future?
I have several Ubuntu virtual machine running within a Hyper-V server. The server is a Windows 2012r2 machine. The Ubuntu VMs are either Ubuntu 14.04 or Ubuntu 16.04 (the current LTS releases).
...
2
votes
0
answers
813
views
Interface being deleted
I have a cluster consisting of CentOS6.5 and CentOS7 virtual machines. I've come across an issue where the network interface, eth0, is being deleted for reasons unknown and I'm looking for help on how ...
2
votes
0
answers
2k
views
DHCP client not getting IPv4 address from a DHCP server
I configured a DHCP server on a VM in VirtualBox. This machine has 2 network adapters, enp0s3 - NAT (from where I have my network connection) and enp0s8 - Internal Network (intnet). DHCP server is ...
2
votes
0
answers
183
views
Abnormal DHCP Android device traffic cannot be identified
Hi Serverfault community members.
I've been trying to identify the source of an abnormal broadcast traffic generated by some Samsung Android devices with no success, so I ask for your help.
I have ...
2
votes
1
answer
449
views
Creating additional VLANs on Cisco SG200
I would like to create 2 separate VLANs using a Cisco SG200-series smart switch (layer 2) where the devices would not see each other, while being able to connect to the internet.
The setup is simple, ...