Questions tagged [dhcpd]

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Assigning option based on class membership inside the subnet section

We are looking for a way to do something along these lines in the dhcpd.conf file: subnet ... { #couple of options for the subnet here pool { allow members of "class-name1"; ...
Andrei's user avatar
  • 91
3 votes
1 answer
1k views

2 client classes sharing the same subnet range

basically I would like to achieve the followings: using only one subnet different types of user sharing this subnets creating 2 pools accordingly an user class called "l2vpn_user" if matched by MAC ...
Simon Lin's user avatar
2 votes
1 answer
2k views

DHCPv6 fixed assigment

Trying to assign fixed ipv6 addresses to my coreos master and worker nodes from my Centos in order to have dual stack running on the cluster. However I am having a hard time getting it to assign the ...
Marlon Goncalves's user avatar
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 ...
Kai Petzke's user avatar
2 votes
2 answers
2k views

Release dhcp lease after forcing client to disconnect

I configured a wifi access point based on OpenWRT to limit the number of clients to 4 at the same time. For that purpose I gave a limited number (4) IP addresses leaseable by DHCP. After a period of ...
AtoM_84's user avatar
  • 21
2 votes
0 answers
2k views

Restrict hostapd wireless client from talking to eachother

How can I keep a wireless client of hostapd from talking to a wired client on the same network or another wireless client on the same network? Here's my network topology: [wired client] --> [...
mkirk's user avatar
  • 733
2 votes
0 answers
100 views

DHCPD does not allow filename option with a colon in it

For some reason, tftpboot does not work with a colon in filename parameter: group { filename "node7:linux/pxelinux.0"; host machine_7a { hardware ethernet 02:01:02:02:01:11; fixed-...
Amumu's user avatar
  • 121
1 vote
0 answers
500 views

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 (scripting or Ansible would also be acceptable). I've tried to locate dhcpd or dnsmasq ...
Sam Erde's user avatar
  • 3,467
1 vote
1 answer
373 views

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 ...
vesperto's user avatar
  • 200
1 vote
0 answers
2k views

What is the exact meaning of "On Commit" in ISC DHCP server configuration?

I know there are three kinds of events we can use for scripting in ISC dhcpd -- commit, expire and lease. My problem is, I am having a little problem in understanding the "commit" event. I ...
Elon20's user avatar
  • 11
1 vote
0 answers
238 views

How to set up dynamic DNS for 'host' in isc dhcpd

I have set up a couple of subnets in my network, and in one of these subnets I'm setting up hosts like this: subnet 10.0.0.0 netmask 255.255.255.0 { option ntp-servers 10.0.0.1; option time-...
Henk van den Toorn's user avatar
1 vote
1 answer
2k views

DHCP and logging fixed address "leases"

I have been tooling with a dhcpd server that i have been setting up for, well, for the general excitement of it i guess. I have a bunch of different configurations. I have noticed that fixed-address ...
the_c's user avatar
  • 11
1 vote
0 answers
92 views

DHCPS - single mac whitelist, multiple subnets

I am trying to reduce the size of my broadcast domain and, in order to do this, I need to permit hosts from being able to move from one subnet to another at will. We use a mac whitelist for our dhcp ...
Simon Elliott's user avatar
1 vote
1 answer
4k views

"match hardware" in dhcpd.conf not working

I've been trying to get mac addresses with a certain OUI into a certain address pool. I haven't been able to get it to work at all. Here is a snippet of my dhcpd.conf and how it's applied. class "...
imlepid's user avatar
  • 175
0 votes
0 answers
25 views

pxe boot: tell client to try next boot option

We have a setup using ISC dhcpd and tftpd to make UEFI PXE clients install their operating system. Once the system is up and running it automatically 'registers' the node by adding a line like this to ...
uli42's user avatar
  • 325
0 votes
0 answers
106 views

Does slave bind9 DNS server answer with dhcpd DDNS updates included?

When I set up ISC dhcpd with a primary and secondary as failover and I have bind9 set up as master/slave and I configure the dhcpd so that it sends the ddns updates also to the slave dns that is set ...
luzze's user avatar
  • 13
0 votes
0 answers
240 views

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 ...
Achyut Kumar Ch's user avatar
0 votes
0 answers
86 views

Configure a DHCP server with isc that gives the clients IPs depending on the OS

The problem is that I cannot put a static IP or filter by mac because some clients have dual boot and use both Windows and Ubuntu, I need to be able to somehow distinguish between both OS and both ...
vicentG's user avatar
0 votes
1 answer
1k views

ISC DHCP for relay agents

I would like to configure DHCP server for my networks, but in the same time, i don't want to setup dhcp server on the network where the server itself is. DHCPD insist to configure subnet declaration ...
Michal Žila's user avatar
0 votes
0 answers
639 views

ISC-DHCP and BIND 9 DNS: DDNS update fails for /27 subnet

I have a problem with DDNS update with ISC-DHCP server. My /etc/dhcp/dhcpd.conf subnet section that doesn't work is: subnet 193.198.186.192 netmask 255.255.255.224 { range 193.198.186.200 193.198....
mt42's user avatar
  • 131
0 votes
1 answer
291 views

Cannot ping anything on intranet or internet when connected to second subnet in isc-dhcp-server

On my local network, I've got Ubuntu Server running isc-dhcp-server and named. I have a lot of devices that I've assigned static addresses to, and up until now have assigned a small range of IP ...
Jeremy Wilson's user avatar
0 votes
0 answers
149 views

No free leases error with a Static CentOS SolusVM KVM slave

I have a KVM SolusVM VPS slave with CentOS 7 that posts this message every couple seconds: dhcpd: DHCPDISCOVER from 00:25:90:cd:xx:xx via viifbr0: network 0.0.0.0/0: no free leases I use a static IP ...
Charles Y.'s user avatar
0 votes
1 answer
64 views

DHCPd IP dispatch

For my tests, the following was done with 2 virtual machines. The server is under CentOS7 and the client under Windows 10 (MAC : 08:00:27:bd:3d:ab). After every modification on the server side, I ...
DSX's user avatar
  • 395
0 votes
1 answer
88 views

Replay DHCPDECLINE to host by edit ethernet address in dhcpd

I known in dhcpd.conf, I can use following config to assigned a fixed ipv4 address to a client. host h1{ hardware ethernet 11:22:33:44:55:66; fixed-address 192.0.2.2; } range 192.0.2....
qin's user avatar
  • 190
0 votes
0 answers
211 views

Dhcpd won't start due to selinux

have searched tirelessly and can't find an answer to this thats not confusing. I have a clean install of centos 6.2 32bit on a machine I use as a router. with selinux enabled dhcpd refuses to start ...
Jacqueline Loriault's user avatar
0 votes
0 answers
47 views

Force dhclient to always provide a unique IP from the available pool

I'm running RHEL 7.4 and the dhcpd is controlled by DD-WRT off my router. Tried to use: dhclient -r; dhclient -x; rm -f /var/lib/dhclient.leases; ip a; dhclient -v but it either returns the same ...
xBlender's user avatar
0 votes
0 answers
1k views

CentOS 7 DHCP server, get IP but cannot ping server or client

I'm trying to create a nat, however, before I can get that far I need to network two PCs via ethernet. The server looks like this: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state ...
Tom B's user avatar
  • 185
0 votes
0 answers
71 views

dhcpd hostgroup in a single file

Is it possible to set dhcpd to read MAC addresses from file, and then to set IP and hostname for those particular hosts? To be more clear - everything is supposed to be in that file: mac, ip and ...
excessive's user avatar
0 votes
1 answer
4k views

how to block incoming DHCP DISCOVERY messages

I'm running ISC DHCP deamon on centOS and want to block unwanted(by clients MAC address) discovery messages before they reach dhcpd. how can I do this with iptables or anything else?
misha's user avatar
  • 13
0 votes
1 answer
268 views

dhcpd daemon taking huge amount of memory and restarting with out of memory error

I have to configure isc-dhcp-server for 1 million clients which listens on 4094 vlan tagged interfaces, where each vlan interface is mapped to a subnet declaration. Therefore in total 4094 subnet ...
user8070445's user avatar
0 votes
1 answer
363 views

dhcpd.conf DNS order is being reset after each cobbler sync

I'm trying to switch the order of DNS servers that my clients machines use by editing the /etc/dhcp/dhcpd.conf file in cobbler. This was the settings before I attempted the change: subnet 10.100.48.0 ...
treetop's user avatar
  • 51
0 votes
0 answers
202 views

dhcp server not starting on CentOS 5 (XenServer 6.5)

I have a host with XenServer 6.5 (based on CentOS 5) that is currently set up using a static IP by following the procedure here. I have been provided with an IP address, netmask and gateway - I ...
edesz's user avatar
  • 101
0 votes
1 answer
511 views

DHCP leases file has 200+ instances of the same lease?

I'm not sure what's going on here. I have a CentOS 7 DHCP server, and the leases file is growing at a linear but steady rate - it's re-issuing the same lease to the same MAC over and over again, and ...
Locane's user avatar
  • 429
0 votes
1 answer
2k views

dhcpd.conf for PXE/BOOTP boot not working

I'm trying to configure the dhcpd.conf file so that when I boot through the network using PXE / BOOTP, a bare metal server or a virtual machine (KVM) would get an IP address in the 10.0.2.100 to 10.0....
GreenTeaTech's user avatar
0 votes
1 answer
1k views

set search domain on dhcp server without changing domain name

Suppose my company's domain is "company.com", our department's domain is "dept". How to set dhcp server in order to let our department's computers to search company.com? Or I have to set up a dns ...
siyuan's user avatar
  • 1