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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8
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3answers
20k 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 ...
6
votes
1answer
1k 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
15k 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 ...
1
vote
3answers
4k 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
3k 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? ...
1
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 ...
1
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 ...
1
vote
4answers
550 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: ...
0
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 ...
6
votes
7answers
8k views

DHCP server with database backend

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 ...
3
votes
1answer
7k views

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 ...
0
votes
3answers
2k views

dhcpd won't let go of old leases

We have DHCP setup to hand out leases in the following range: 192.168.10.190 - 192.168.10.254 (roughly 65 leases) Our small business network only has about 30 computers that use DHCP. We noticed ...
1
vote
7answers
960 views

Audit reserved IPs for UNIX/Linux ISC-DHCP

Are there any good FOSS tools to do an audit of reserved IPs used in a Linux/UNIX ISC DHCPd environment? I'm trying to ensure that we do not have stale IP addresses reserved when old MAC addresses ...
4
votes
1answer
979 views

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 ...
0
votes
1answer
1k views

Accessing DHCP Client's vendor-encapsulated-options

In the dhcpd.conf file for isc-dhcpd-V3.1.1, I have set up a vendor options space and defined several different options. I am able to use those definitions to send options from the server to the ...
2
votes
2answers
933 views

Automatic subdomain wildcard for DHCP-DDNS additions?

I'm running dhcp-4.0.2 server and bind-9.6.1-P3. When a new Mac OSX DHCP client with the name "harry" connects to the network, the DHCP server gives it a lease, and adds appropriate A & PTR ...
5
votes
3answers
1k views

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
votes
1answer
6k views

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; }
8
votes
4answers
3k views

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 ...
4
votes
3answers
1k views

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 ...
4
votes
2answers
9k views

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). ...
3
votes
5answers
5k views

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 ...
2
votes
4answers
4k views

Option 82 and dhcpd. “No free leases” for second computer

There is DHCP server in network (isc-dhcpd-server-3.0 on FreeBSD 7.2) than gives one IP per switch port to every user via Option 82 The problem appears when user disconnects one of his computers and ...