Questions tagged [isc-dhcp]
ISC DHCP is open source software that implements the Dynamic Host Configuration Protocols for connection to a local network. It is a reference implementation of those protocols, but it is also production-grade software, suitable for use in high-volume and high-reliability applications. DHCP is available for free download under the terms of the ISC License, a BSD style license.
259
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DHCPDISCOVER/DHCPOFFER, but no DHCPACK
I have a remote client machine that is sending out DHCPDISCOVER's.
The server is responding with a DHCPOFFER, but there is no DHCPACK.
This repeats about every 30 seconds from the same host. Is ...
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16
votes
3
answers
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ISC DHCP infinite lease time
How can i configure ISC DHCP server to infinite lease time for all clients?
man dhcpd:
Lease Lengths
DHCP leases can be assigned almost any length from zero seconds to infinity. ...
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12
votes
2
answers
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How to ignore a set of Mac addresses in dhcpd.conf?
Is it possible in dhcpd.conf to ignore requests from a set of MAC addresses?
Something like this:
host vminstances {
hardware ethernet d0:0d:*;
ignore booting;
}
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11
votes
1
answer
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Is "broadcast-address" necessary in dhcpd.conf?
Or, more generally, is it required to specify the broadcast address that a client should use when a DHCP server is assigning an address?
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How to configure radvd, dhcpd6, routing and /64 subnet based on delegated prefix by DHCPv6-PD server?
My ISP has just started IPv4/IPv6 dual stack service. In order to connect IPv4/IPv6 internet, almost all users usually use a CPE leased by the ISP. But I want to use my Linux router instead of such ...
- 261
9
votes
2
answers
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Assign DHCP IPs for specific MAC prefixes
I'm running a ISC DHCPd server for my network serving a number of subnets. One of the things I would like to do is assign a specific range of IPs to hosts with a common MAC prefix (ex. 00:01:02). Also,...
- 257
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votes
1
answer
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Can I request a specific IP address via DHCP without rejecting an offer of a different address from the DHCP server?
Using isc-dhcp-client on ubuntu server 16.04, there's an option that sounds like it should do what i want:
send dhcp-requested-address 10.23.33.254;
When this option is present in my dhclient.conf ...
- 190
8
votes
7
answers
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DHCP server with database backend [closed]
I have been looking around for something to replace my (ancient) ISC-DHCPd server.
A DHCP server with a database backend sounds like a great idea to me, as I could then have a nice, friendly web ...
- 1,588
8
votes
4
answers
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DHCP on-the-fly block assignment
We have a large number of clients who connect to our DHCP machine. We want to assign some of them to a different IP block, which is routed with lower priority. Every DHCP lease renewal, we'd like to ...
- 953
7
votes
3
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Exclude IP address from DHCP pool
Is there a way to exclude a single IP address from a DHCP pool? For various reasons I have a machine that I can't reconfigure or move off the network (let's call it a printer). It has been hard coded ...
- 388
7
votes
4
answers
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Windows 7 Client flooding network with DHCP requests. Not setting IP
I have a small network, with 15 workstations, SAMBA AD, and a bunch of Virtualized linux servers. All the workstations, and servers are on the same subnet.
All workstations are running Windows 7 Pro
...
- 71
6
votes
1
answer
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How do I assign hosts to classes in ISC DHCPD?
Suppose I have a bunch of hosts set up like this:
host host2 { hardware ethernet 10:bf:48:xx:xx:xx; fixed-address 192.168.1.2; }
host host3 { hardware ethernet 10:bf:48:xx:xx:xx; fixed-address 192....
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6
votes
5
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DHCP: Logging host declarations in log file
I am currently running ISC-DHCP server v3 on Ubuntu 8.04. What I am trying to do is log Who got what IP address when.
Currently in the DHCP log file you can see the following:
DHCPDISCOVER from ...
- 443
6
votes
3
answers
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Can ISC DHCPD operate as a Proxy DHCP server for PXE boot?
I have an existing LAN with a DHCP server already dishing out IP addresses.
For various reasons I cannot replace that server so it will still need to dish out IP addresses.
I've been experimenting ...
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6
votes
1
answer
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Fixed and dynamic IPs in ISC DHPD lead to double lease
I would like to have a small dynamic adress part and the most clients are assigned a fixed IP adress.
My dhcpd.conf looks like this:
use-host-decl-names on;
authoritative;
allow client-updates;
ddns-...
- 487
5
votes
2
answers
7k
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DHCPv6: passing delegated prefix to local RA
I currently have an Airport Extreme as my home office firewall. In addition to handling IPv4 NAT, my ISP (Comcast) delegates an IPv6 prefix to the Airport, which in turn assigns the delegated prefix ...
- 389
5
votes
4
answers
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Can't start isc-dhcp-server because of the Error : Not configured to listen on any interfaces
I try to set up a wifi access point with hostapd and isc-dhcpd but the dhcp server dont work.The conf file is the same i found in this tutorial: [Hostapd : The Linux Way to create Virtual Wifi Access ...
- 51
5
votes
2
answers
7k
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isc dhcp class with more match
Is there any way to define more matches with OR?
I would like to create a class with a mac address check, like
class "fixVms" {
match if substring (hardware, 1, 4) = 00:15:5d:aa;
}
but I would like ...
- 53
5
votes
2
answers
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DHCP: One NIC and multiple subnets
I'm setting up a Debian to work as a gateway for a small office network. I need to have three subnetworks for different areas within the company and I will define which PCs will get what IP based on ...
- 973
5
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2
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Why do I get "No subnet declaration" starting ISC DHCP server on subinterfaces?
I have created two subinterfaces on eth0 :
eth0:0 with IP 192.168.10.1/24
eth0:1 with IP 192.168.11.1/24
Configured /etc/dhcp/dhcpd.conf like that:
option domain-name-server 194.204.159.1;
subnet ...
- 51
5
votes
2
answers
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Is it possible to run pre-Lion OS X in an IPv6-only environment without static configuration? [closed]
Is it possible to run pre-Lion OS X in an IPv6-only environment without static configuration? From what I've been able to figure out, OS X 10.6.x will acquire an address via SLAAC, but it doesn't ...
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5
votes
3
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3k
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Where is dhcpd's syslog message formats documented?
I am looking at bunch of syslog messages written by dhcpd. I want to write a quick parser that can deconstruct the message into its component parts, but I don't know what the various parts mean. I ...
- 2,053
5
votes
0
answers
3k
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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 ...
4
votes
1
answer
18k
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ISC DHCP Server "Dynamic and static leases present"
i have a problem similar to Fixed and dynamic IPs in ISC DHPD lead to double lease
In my DHCP-Log I often receive warnings like
Jan 21 10:20:56 dc2 dhcpd: Dynamic and static leases present for 192....
- 73
4
votes
2
answers
9k
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DHCP failover with isc-dhcp-server using two secondary servers
I'm rearranging our network and putting some DHCP failover since we have a lot of machines, and even servers, getting IP addresses with DHCP.
Today we have a nice DNS topology with one master server ...
- 5,540
4
votes
2
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3k
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Prefix Delegation and route creation
I'm using the ISC dhcp server version 4.1 for DHCPv6 prefix delegation on a network. When the server allocates a prefix to a client, the server does not create a route for that prefix to the client ...
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4
votes
2
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Web interface for managing an ISC DHCP server
I am looking for a web interface to administer an ISC DHCP server. I have the setup of one Debian Linux box running an ISC DHCP server and I would like to add a second DHCP server as failover.
To ...
- 487
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votes
2
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isc-dhcpd static ip within range
I have a isc-dhcpd server with dhcp-range 10.0.0.10 - 10.0.0.20.
There is also a device connected with static ip 10.0.0.10.
What would happen when a client with dynamic ip connects to the network?
...
- 41
4
votes
3
answers
3k
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A Linux DHCP server that will listen on an non-broadcast (tap) interface?
Are there any Linux DHCP servers that will listen to what Cisco calls an "unnumbered" interface, or what others might call a "NBMA" (non-broadcast) interface.
I have a Linux system that connects to a ...
- 7,991
4
votes
1
answer
488
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rfc 6939 support for dhcpv6 relay
isc-dhcp-server now supports rfc6939 as of version 4.3, and I would like to be able use it as it is quite nice to be able to just use the mac address to identify dhcpv6 clients. However, I can't seem ...
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1
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dhcpd.conf "Configuration file errors encountered"
I want to set up the isc-dhcp-server, but the dhcp.conf file generates an error while testing with dhcpd -t:
...
/etc/dhcp/dhcpd.conf line 6: expecting a parameter or declaration
authoritative;
...
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votes
1
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DHCP scope for a user class option
In Linux how can I set a DHCP server configuration which will lease IP addresses from scopes which are defined according to user classes. For example the following configuration leases IP addresses ...
- 211
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votes
1
answer
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How does broadcasting work on a server with multiple IPs?
Say you have two dhcp servers, A and B.
Server A has two IP addresses, 10.0.0.1 and 10.0.0.2.
Server B has one IP address, 10.0.0.3.
Server A has two instances of isc-dhcp running, one specifying a ...
- 171
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votes
1
answer
3k
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DHCPREQUEST and DHCPACK spam in logs
I've recently noticed that my android phone (droid dna, although the thunderbolt that I had before did the same exact thing) is rapidly requesting dhcp info my dhcp server (isc-dhcp-server on debian ...
- 1,447
4
votes
1
answer
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Windows 2003 DNS updates from ISC DHCP server
We have a very mixed network, with most clients being Debian Lenny, the rest Windows XP/Vista/7. The network itself is split into two segments (for technical reasons) called "corporate" and "...
- 8,867
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votes
0
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Samba4 internal DNS and isc-dhcp zone update
Could anybody explain, how to solve this problem with internal samba4 DNS and dynamic zone updates from isc-dhcp?
In the logs I have:
dhcpd: Unable to add reverse map from 170.5.168.192.in-addr....
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0
answers
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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 ...
- 183
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1
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Can I prevent Debian from hitting DHCP server twice during installation?
I have a DHCP server used to do unattended installations of Debian: boot from PXE, and then install the operating system with a preseed.
The DHCP server (Debian's isc-dhcp-server package) is ...
- 2,275
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2
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Iptables - Allowing only a single dhcp (relay) client
I am trying to create a firewall rule on an Ubuntu 10.04 server running isc-dhcpd. I only want dhcp to be accessible by a single relay host (172.1.1.1). I have iptables set up like so:
# iptables -...
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1
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Aliased network interfaces and isc dhcp server
I have been banging my head on this for a long time now. There are many discussions on the net about this and similar problems, but none of the solutions seems to work for me.
I have a Debian server ...
- 145
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votes
1
answer
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Is there a match on incoming interface in DHCPd classes?
(Note, the title of the question Is there a way to classify DHCP requests based on the interface they're coming from? is what I want answered, but it doesn't actually ask that question for a non-...
- 213
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1
answer
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How can I configure dhcpd to only update the reverse zone in bind?
I've got dhcpd pushing updates to bind, and it seems to be working fine:
named[24161]: client 192.168.10.1#59141: signer "dhcp_updater" approved
named[24161]: client 192.168.10.1#59141: updating zone ...
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2
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How to generate DHCP Decline scenario / packets
I have a dhcp packets sniffer, which needs to log if it sees dhcp decline response coming from client.I need to know the scenario where client can send dhcp decline response to dhcp server.
I tried to ...
- 51
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votes
1
answer
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Cannot assign IP address according to an option parameter
I have this DHCP conf file:
authoritative;
option domain-name "XXX.XXX.XX";
allow bootp;
ddns-update-style ad-hoc;
class "karpuz-kabugu"
{
match if (substring (option user-class, 0, 6) = "karpuz")...
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1
answer
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Windows 7 Failing Ping on IPv6 in DHCP Setup
I have set up a test ISC DHCP server that is not connected to an internet with DHCP and DHCPv6. I also have a Cisco 3750G with IPv6 enabled. I have firewalls off on both machines.
My Windows 7 ...
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votes
1
answer
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How to tell ISC DHCP correct zone for reverse zone DDNS update?
I've got an ISC DHCP server running (version 4.2.5) which is configured to dynamically update the reverse zone on a DNS service with the hostname it receives via a dhcp DISCOVER package.
It all works ...
- 333
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votes
0
answers
642
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Can ISC-DHCP bind to Option 82 rather than Mac Addresses?
We use option 82 information to limit leases presently in ISC-DHCP using a spawn with statement for our billing subclass. This keeps a single household/business from obtaining more leases than they ...
- 171
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votes
0
answers
2k
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proxy autoconfiguration: windows does not download wpad.pac file
I am trying to configure my dhcp server on Debian Wheezy to reply to DHCP INFORM and send a url where my Windows client may download the wpad.dat file.
Here is the configuration file:
option local-...
- 2,313
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1
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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 ...
- 31
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votes
4
answers
4k
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Fixed dhcp host to automatically expire any lease
I have the following situation: Multiple offices with multiple firewall/dhcp servers.
Every time the IT team of some office plugs a new network printer i need to create a fixed-address entry, and ...
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