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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Advanced DHCP configuration (isc-dhcp-server)

We are managing our network by using DHCP and we sometimes add new subnets (IP Pools) to network through different VLANs. What we want to do is to manage all those IP pools from same DHCP server but ...
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1answer
22 views

Ubuntu server dhcp reservation not working

I need some suggestion, if possible, about a dhcp server and ip address reservation. The system is a Ubuntu server 12.04 LTS. The DHCP is ISC DHCPd version 4.1. This is the /etc/dhcp/dhcpd.conf ...
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2answers
36 views

DHCPD assigning wrong DNS server

I just installed two Ubuntu 14.04LTS servers. The first one I installed bind9 and isc-dhcp-server on. The second one was left as installed to use DHCP. I created a new private network using VMware ...
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39 views

DHCP offer is unicast but DHCPACK is broadcast

My DHCP server broadcast DHCPACK 0xffffffff . it is not working on layer 3 dhcp relay agent . as it can not forward this broadcast message to my client. can any one help me from exactly the broadcast ...
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72 views

isc-dhcp-server and option 242

Trying to set up option 242 for an Avaya phone demo on our isc dhcp server. I am using the following configuration: option option-242 code 242 = string; subnet 10.30.0.0 netmask 255.255.0.0 { ...
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1answer
58 views

Multi-homed forward zone DDNS updates always sent out the same network interface

I have a multi-homed server 'dhcp1' with network interfaces '192.168.10.151' (eth0) and '192.168.0.151' (eth1). The machine is attempting to use DDNS with a name server 'ns1' having network interfaces ...
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3answers
171 views

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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1answer
351 views

ISC DHCP server not dynamically updating DNS

I have an Ubuntu 14.04 server, running an isc_dhcp_server and the bind9 DNS server. Bind acts as a cache, and it maintains the .m domain (and zone) on my local network. The server's address is ...
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1answer
28 views

ISC DHCP Server scope error

Why am I getting the following error after modifying my dhcpd server config? option space definitions may not be scoped
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1answer
77 views

ISC DHCP - different subnet for specific mac addresses

I'm attempting to create a different subnet for a few specific mac addresses, and have my DHCP config set up as follows: authoritative; shared-network local { subnet 192.168.2.0 netmask ...
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2answers
109 views

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 ...
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1answer
60 views

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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0answers
37 views

isc-dhcp-server sends OFFER to ip and not broadcast

I'm trying to set up the isc dhcp server. My config looks like: ddns-update-style none; default-lease-time 600; max-lease-time 7200; # If this DHCP server is the official DHCP server for the local ...
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1answer
111 views

Using isc-dhcp-server to allocate addresses from subnet different from server subnet

I'm trying to break my network into different subnets. Server is located into 192.168.15.0/24 subnet. I have the following declaration in my dhcp.conf: subnet 192.168.15.0 netmask 255.255.255.0 ...
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0answers
69 views

DHCP fault tolerant servers: Split spool 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 ...
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1answer
1k views

SLES DHCP Dynamic DNS: Unable to add forward map…: not found

I have a SUSE Linux Enterprise Server 11.3 install running on Amazon EC2 based off the official AMI. With DHCP and BIND configured (via yast) I'm having issues with Dynamic DNS. When a client ...
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1answer
80 views

Is it possible to send different-per-subnet DNSes from the single ISC DHCP server?

The case I want to cover is to send different DNS server for one, isolated VLAN, which purpose is to give internet-only access - for our guests. It has no access to our internal network, so it ...
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1answer
88 views

Enterprise DHCP server solution? [closed]

I have a network of about 1000 assorted devices, all of witch are running by static IP addressing. Given the size of the network and the lapse of technical advice, the addressing scheme is in chaos ...
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1answer
106 views

ddns correct setting for dhcpd.conf and ifcfg file with regards to hostname

I have recently set up dynamic dns with ISC dhcpd 4 and bind 9. Everything is working as it should except for a handful of hosts on the network which don't resolve. Upon investigating I found they had ...
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0answers
91 views

How do I stop a Linux computer from sending a DHCP hostname?

I need to set up a Linux computer so that it uses DHCP but doesn't send any hostname at all. I'm using isc-dhclient-4.2.4 /etc/dhcp/dhclient.conf contains the line send host-name = gethostname(); ...
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0answers
62 views

dhcpd set ddns-hostname from client supplied hostname

Basic issue: I'm trying to setup BIND and DHCPD. I have both working and the only problem is DHCPD cannot update BIND zones with names of dynamic clients (those without static leases). By trial and ...
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1answer
264 views

dhcpd not pushing ddns updates to bind

BIND and DHCPD are configured but as far as I can tell DHCPD makes no attempt to even send Dynamic DNS update to BIND. I can manually add records using nsupdate with the same key I have configured ...
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1answer
348 views

Multiple subnets on isc-dhcp-server using ddns with bind9

On my network I have two subnets: 10.100.1.0/24 -> Wired/wireless 10.100.7.0/24 -> VPN Both subnets are served by isc-dhcp-server running on a Debian VM. This same VM runs bind9 for my DNS. ...
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0answers
61 views

DHCP server with ability to update mac address dynamically

Is there a better way to maintain MAC to IP specification in dhcp with out restarting dhcp service each time when there is an update. is it possible to use DHCP with database in Linux to save all ...
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1answer
771 views

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 ...
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2answers
524 views

Assign two static IP addresses to one mac address

Can Isc-dhcp-server give two static ip addresses to one mac address? I have several Genexis terminals in my network. Each terminal have two interfaces, one for public traffic and one for a management ...
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0answers
118 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. ...
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0answers
92 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 ...
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0answers
55 views

Ubuntu server DNS/DHCP/MAAS woes

I've been using Ubuntu server Raring for a few weeks now. It seems to be great, but I havre a slight problem. I opted for the Metal As A service option, and now its changing my DNS records and going ...
2
votes
1answer
256 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 ...
2
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1answer
180 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
1k 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
128 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 ...
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0answers
96 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
251 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 ...
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2answers
1k 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
222 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
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1answer
246 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 ...
3
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0answers
432 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
74 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
49 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 ...
2
votes
2answers
5k 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 ...
2
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1answer
3k 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 ...
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1answer
127 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
1k 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 ...
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1answer
517 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 ...
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1answer
440 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
94 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
1k 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
1k 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 ...