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 ...

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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. ...
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0answers
205 views

How to send several instances of the vendor-specific options to a DHCP server using dhclient?

I need to send vendor-options to DHCP server using dhclient (ISC). I've added following lines in the dhclient.conf: option dhcp6.vendor-class code 16 = {integer 32, integer 16, string}; send ...
2
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1answer
1k views

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 ...
4
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2answers
410 views

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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4answers
5k views

Computer gets IP from DHCP server but has no internet connection

I've installed an isc-dhcp-server on Ubuntu 12.10 and I'm trying to setup a DHCP server on a head node for six worker computers in the local network. The head node itself is a DHCP client receiving ...
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1answer
186 views

DHCP IPv6 and vendor-encapsulated-options

I was using this option on ipv4 to send some information to the host. On my host lease I have something like: supersede vendor-encapsulated-options = "MY INFORMATION"; On the DHCP client host I can ...
2
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1answer
186 views

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) = ...
4
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1answer
582 views

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 ...
4
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2answers
5k views

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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0answers
345 views

How to filter out/disable DHCP NAK responses?

We have some crappy situation where we don't have control over the existing DHCP server on the network and where we need to add another BOOTP/DHCP server with the authoritative directive. Our ...
4
votes
1answer
323 views

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 ...
4
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1answer
1k views

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 ...
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1answer
124 views

How to forward gateway requests for a subnet through another connection under Linux

I have a Debian machine acting as a DHCP server/NAT, connected via PPTP to another machine,connected to a subnet 10.0.0.0. How do I configure it so requests from clients on this machine for the ...
2
votes
1answer
55 views

Changing DHCPv6 server

I have a DHCPv6 daemon that is answering for requests of some machines and everything is working fine. So I decided to remove this DHCPv6 daemon e start another daemon on another server, but the ...
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votes
4answers
11k views

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 ...
3
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1answer
6k views

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 ...
1
vote
1answer
149 views

Can I run 2 dhcp servers when I use predefined host entries?

I have a very specific setup of servers which netboot off a san. All of them provide identical functionality. There are no other machines in this netblock. Each machine boots from an iscsi image ...
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1answer
3k views

PXE boot linux. PXE-E51: No DHCP or proxyDHCP offers were received

I am trying to have an ubuntu box (192.168.10.9) acting as a PXE server, but i have trouble getting DHCP to work. The PXE server is connected to a SOHO router (192.168.10.1) acting as a switch. I have ...
2
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1answer
985 views

When does ISC dhcpd expire leases

When exactly does ISC dhcpd forget a lease that is not explicitly freed by the client? Context: I am running an installation with many small pools (3 address) and it does not seem to cope well when ...
2
votes
1answer
716 views

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? ...
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0answers
125 views

How to make ISC dhcpd not log a specific hardware ethernet address (mac)

I have isc dhcpd v3 serving a local subnet. I have installed a rogue dhcp server detector (dhcp_probe) which constantly sends dhcp requests. These requests are logged by the legit dhcp server, filling ...
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1answer
3k views

Replies to request coming over a relay goes to relay's internal IP, not to original request's source IP

Dhcpd running on Linux gets a dhcp request over dhcrelay which is running on other remote machine. Oct 6 10:09:46 2012 dhcpd: DHCPDISCOVER from 00:1e:68:06:eb:37 (oguz-U300) via 172.16.17.81 ...
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1answer
2k views

Setting up ISC-DHCP server getting DHCPDISCOVER, DHCPOFFER constantly

Working on trying to setup a new server to run FOG on. I have setup the server to serve DHCP addresses only on eth1 and not eth0. I have installed isc-dhcp and bind9 on the server. I cannot get a ...
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3answers
3k views

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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1answer
244 views

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 ...
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3answers
2k views

isc-dhcp option82

I have a question about correct isc-dhcp configuration. I want to lease ip addresses to users based on switch port. For this I use DLink DES-3200 series switches. Everything works well, but recently ...
3
votes
1answer
5k views

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 ...
2
votes
1answer
337 views

Assigning DHCP subnets to users based on hardware

On our network, each user gets their own octet, eg Fred gets 10.2.105.0/24 and Barney gets 10.2.106.0/24. They get a laptop and a development server from IT with a known mac address. What I want to ...
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vote
0answers
315 views

ISC-DHCPD failover, Modifying host definitions via OMAPI

Background: I'm working on replacing my single DHCP server with 2 in a failover configuration. When I do a DHCP request I see the lease is created in both dhcpd.leases files on each server. However, I ...
1
vote
1answer
472 views

dhcpd: varying vendor-class-identifier

I'm having trouble selectively sending parameters in response to a DHCP Inform packet using groups (or even without, just using host declarations) for bootp stuff. My configuration file right now ...
3
votes
1answer
8k views

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; ...
2
votes
2answers
6k views

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 ...
5
votes
2answers
135 views

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 ...
1
vote
3answers
308 views

ISC-DHCPD: why does it cease to work when the internet is down?

For as long as I've been using a DHCP server on Linux or even FreeBSD (all come from ISC if I recall correctly), it seems that it just doesn't know what to do with DHCP requests when the Internet goes ...
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vote
1answer
3k views

ISC-DHCP-SERVER - Can different reservations get different options (router, DNS, etc)?

Suppose there's just one Ubuntu / ISC-DHCP (v3) server on the network. I've successfully been able to provide "DHCP reservations" meaning MAC foo gets ip 1.2.3.4, whereas everyone else just gets an ...
0
votes
1answer
547 views

isc dhcpd: how to insert option 61 (client id) into dhcpoffer

I have a quick question. Is it possible to make ISC dhcpd server insert the option 61 (client id) in DHCPOFFER, in case if it is present in DHCPDISCOVER? The ISC dhcpd version I'm using is dhcp-4.1.1 ...
0
votes
1answer
1k views

Force windows 7 to update dns through dhcp server?

I have setup a new BIND9 to allow dynamic updates from my DHCP3 server. I am securing it using a DNSSEC key. Everything appears to work except when my windows workstation grabs an IP address it tries ...
0
votes
1answer
532 views

Is it possible to make ISC dhcpd (IPv6) 4.2.2 unicast-only?

I ask because the server is handling DHCPv6 for two VLANs and I can see some requests both via DHCPv6-relay from our ProCurve switch and via the ff02::0:2 anycast address and responds to both ...
1
vote
2answers
239 views

DHCP configuration problem

EDIT: We have following setup: User comes to building, he gets address from range for unknown clients (192.168.100.0/25) and can only get to our web site. We call it anonymous range. Let's say our ...
8
votes
3answers
18k views

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 ...
5
votes
1answer
896 views

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?
3
votes
3answers
13k views

Exclude IP address from DHCP pool

Is there a way to exclude an ip address from dhcp pool? For various reasons i have a machine that I can't reconfigure or move off the network (lets call it a printer). It has been hard coded an ...
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vote
3answers
3k views

modify dhcpd.conf via script to convert whole subnet to DHCP reservations

We have a hodgepodge of systems that are either static IP addresses, or DHCP reservations. (We don't hand out any addresses except reserved ones). Some servers have multiple Nics, and ILO cards. Its ...
2
votes
3answers
1k views

Monitoring an ISC DHCP Failover Status Using Nagios

I recently implemented ISC DHCP Failover and it's working beautifully, but I'd like to monitor the current status of the failover using Nagios. Ultimately, I would like my Nagios check to: report ...
2
votes
1answer
2k views

ISC DHCP server: how many IPs are in use?

I'm wondering what is the correct way to count how many IPs are in use in my network according to the dhcpd process. Is it just a matter of counting "binding state active" lines in dhcpd.leases file? ...
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vote
2answers
5k views

ISC DHCP - Force clients to get a new IP address, instead of the being re-issued their previous lease's IP

We are in the middle of a migration of our DHCP and DNS services from a Debian-based server to a Windows Server 2008 R2 implementation. The Debian server is running isc-dhcpd-V3.1.1. All of ...
2
votes
2answers
2k views

Is the native DHCP client for MacOS X able to send “Vendor class identifier” (opTag 60) in a DHCP request?

Is it possible for MacOS X (current version or in any previous one) to easily force DHCP client to send to DHCP server, at the beggining of the conversation - in DHCPDISCOVER packet - option "Vendor ...
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vote
2answers
2k views

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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4answers
511 views

why would dhcp listen port 80

I have a CentOS server with isc dhcpd and apache 2 webserver running. A couple of minutes ago I have tried to restart apache: /etc/init.d/httpd restart Restart has failed with: Starting httpd: ...
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votes
1answer
5k views

dhcpd, DISCOVER, “no free leases”

I am attempting to set up a VERY simple DHCP server. I am using Ubuntu 10.04, and I installed the "dhcp3-server" package. The server has one interface (eth0) statically set to 10.0.0.10(/21). I want ...