DHCP stands for Dynamic Host Configuration Protocol and is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol.

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When installing Windows Server 2012 R2 Essentials, should DHCP be turned off first on router? [on hold]

Or should it be left on for setup, then DHCP on router turned off after setup so server does DHCP. Thank you.
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25 views

Windows DHCP Clients Randomly Revert To Old DNS Servers

In this one network I have, I am moving from a linux infrastructure to a Windows infrastructure. This has been a staged process. Originally there was no Windows infrastructure. DNS, NIS, and DHCP ...
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18 views

Virtual Box local network [on hold]

I have a VM running on Windows using Virtual Box and Vagrant. How do I assign a local network IP address to this VM using a local DHCP? The requirement is for this VM to be visible on the local ...
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4answers
728 views

When the internet is down, so does Active Directory?

I am setting up business servers for a small office use with 5 users / 5 devices or so. Nothing elaborate here. I've set up a SINGLE Lenovo TS440 server (single NIC) with Windows Server 2012 R2 ...
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1answer
25 views

Getting “Connection timed out” on a tftp server though it seems everything is configured correctly, what could be the reason?

I've just installed a cobbler (with tftp/dhcp) server on a CentOS 6.6 machine at work. I've configured tftp to run under xinetd and the conf file looks like so: service tftp { disable ...
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1answer
16 views

Is it possible for networks to be assigned the same external ip [closed]

Is it possible for networks to be assigned the same external ip, not necessarily simultaneously, for example being assigned another users old external ip address? I am a programming student but my ...
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1answer
25 views

Auto DHCP IP Phones to a different subnet

I'm standing up a 3CX PBX system in my office and would like to set my DHCP to assign IP phones a 10.10.8.x address, while giving everything else a 10.10.0.x address (our current net). What would be ...
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0answers
26 views

How did AirPort's DHCP “Welcome Message” work?

I remember that Apple's AirPort base stations used to have a DHCP "Welcome Message" feature, that would display a custom pop-up dialog when computers connected to the network. How was this ...
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42 views

VLAN ID over DHCP for Management Interface of Fortinet FortiAP

When configuring the FortiAP device it's desirable to configure the VLAN ID for the tagged management network. Accordingly to the manual it's possible to do so by "telnetting" to the FortiAP device ...
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2answers
33 views

Is there any lower bound on DHCP lease time?

Currently I am facing an issue to change the value of the DHCP lease time option in the server and configuring the the client with the same value. I have used dhcp-server package and have put the ...
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1answer
31 views

Certain PC's on vlan using link local 169.254.x even though communication present to DHCP Server?

I would really appreciate thoughts and opinions on this strange issue experienced recently. Consistent behaviour noted from problem clients: Up to a certain time in the morning user PC's were ...
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1answer
31 views

Cascade 2 routers with dhcp [closed]

I'm wanting to cascade 2 routers, one is a Linksys E3000 Router, the other is a wireless Cable Modem/Router made by Arris. As of now their cascaded via WAN to LAN, in other words, the internet port ...
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0answers
16 views

specific IP Attribution with isc-dhcp-server with freeradius authentication

I would like to assign specific address to my clients, regarding their radius authentication. For exemple, user1 (group user) authenticate on radius, dhcp gives him 192.168.1.1 as IP user2 (group ...
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0answers
22 views

Polycom phone not requesting DHCP offer

My Polycom IP550 phone is not requesting the DHCP address that my windows 2012 server offered it. I have done a wireshark capture on a mirrored port on our switch and you can see that the phone is ...
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0answers
31 views

Under CentOS6.5, DNS Server build with DHCP, Client can't ping domain-name, but IP can

I'm trying to build a DHCP and DNS server. I check that client ip is ok to capture (11.11.0.1), ping server ip (11.11.0.9) is ok, but ping domain name (example.com) is not ok. On the server, ping ...
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2answers
88 views

Can I disable DHCP client on my Windows 2012R2 server (which uses static IP)?

I looking through the services list on some of the Windows 2012 R2 servers here and noticed that DHCP client is running, despite the servers using static IP on all interfaces. This seemed like a ...
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1answer
48 views

Under Centos 6.5, restart dhcpd with dhcpd.conf failed: expecting IP address or hostname option domain-name-servers “11.11.0.9”

I'm trying to build a DHCP and DNS server. I check that client ip is ok to capture (11.11.0.1), ping server ip (11.11.0.9) is ok, but ping domain name (example.com) is not ok. On the server, ping IP ...
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1answer
23 views

How to set DHCP IPs of stanard lxc containers?

When you create some containers on a host, e.g: sudo xlc-create -n container1 -t ubuntu sudo xlc-create -n container1 -t ubuntu the lxs system creates IP address for the hosts on a new subnet, e.g. ...
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1answer
26 views

Setup Windows Deployment Services when option 66 is already in use

I am currently trying to setup WDS at my company. The WDS and DHCP are running on two different servers. However, our IP telephony system is currently using option 66 (Boot Server Host Name) in ...
0
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1answer
20 views

DHCP attribution without DHCP client

j'ai un serveur DHCP qui attribue des IP selon les adresses MAC des clients. J'ai un client qui n'a pas de client DHCP installé (pas que je sache). I have a DHCP server (on linux) which gives IP ...
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2answers
42 views

How to block DHCP traffic using iptables

First let me describe my environment: There is a VM (CentOS) acting as a gateway The gateway VM has to NICs, eth0 connects to public network, eth1 connects to private network eth0 get IP from public ...
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0answers
56 views

Create Bridge interface on linux board

My current configuration and topology look like below: +++++++++++++++++++++++++++++++++ +++++++++++++++ | Linux Board eth0 | | Switch | | with openWRT ...
1
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1answer
19 views

Different lease time for all clients DNSMASQ

We are running a small DHCP server on Raspberry PI using DNSMASQ. We need to give out lease time based on a script that gives us the time span. This means that all clients will have a different lease ...
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2answers
99 views

Debian Jessie : dhclient always active

On fresh installs of Debian Jessie, after I set a static ip address, the DHCP client is still active. It even revert back to the dhcp ip address when the lease is renewed. step 1: I modify ...
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1answer
59 views

Multi Vlans with one DHCP server [closed]

We have multiple vlans configured on Cisco 4506, two of them with dhcp enabled to serve living area inside our company and wireless. I installed a new DHCP on windows server 2008 r2 and planning to ...
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1answer
25 views

Ubuntu DHCP Server not assigning itself an address

I am setting up a virtual environment inside an ESXi server. I have a version of Ubuntu Server running isc dhcp. When the server boots up I issue the command ifdown eth0 followed by the ifup eth0. ...
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4answers
63 views

Misunderstanding of DHCP/DNS - What is the IP of a machine before DHCPOFFER/DHCPREQUEST

From what little I understand, DHCP allows for dynamic assignment of IP addresses to client machines on a network from a DHCP server. The client transmits a DHCPDISCOVER packet, followed by a ...
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0answers
26 views

Using Microsoft DHCP with Linux PXE/TFTP/kickstart

I have a microsoft dhcp server already in the network and i have linux servers for pxe/tftp/kickstart. I would think that it would work using a ms dchp server with pxe/tftp on linux but im not sure, ...
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0answers
87 views

Use Framed-IP-Address RADIUS attribute for IP allocation with DHCP on Windows Server 2012R2

I have configured a DHCP server on Windows Server with an NPS Policy, connected to a FreeRADIUS2 server running on pfSense. Authentication is based on MAC address. If MAC address is not present in ...
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1answer
44 views

DHCP Server Not Registering PTR Records

I've got a DHCP server that's configured to "Always dynamically update DNS records". Unfortunately, it's not doing its job. The client sends an Option 81 with its FQDN and all flags at 0. The ACK back ...
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1answer
44 views

Linux Server Update Windows Server DNS (DHCP Not Windows)

I have Linux machines that are DHCP clients that have send hostname enabled but are not updating DNS on the Windows servers. DHCP is coming from the firewall, NOT Windows. Other windows machines ...
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1answer
46 views

Internet bandwidth split with HP1810-8G, using “DSCP QoS policies” and VLANs

I have the following scenario: We are a small company (~10 clients) with little resources and we rented out office space to another company(<5 clients). We ordered a 20 Mbit fiber connection which ...
1
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1answer
43 views

DHCP with fixed IP hosts (Ubuntu)

I'm managing an office system that assigns IPs based on the MAC address. The fixed hosts are added in a dhcpd-hosts.conf file which is included in dhcpd.conf. There are some PCs that are not in the ...
4
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2answers
74 views

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; ...
0
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1answer
62 views

lan to wan connection refused by windows firewall

I have plenty of experience with LAN's and bridges however this is my first time using a WAN style setup... here is a diagram of my network WAN (public ip & 10.1.10.1)---COMP1 (10.1.10.2) ...
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0answers
25 views

DHCP Config for Server 2012 R2

This question may have been covered before, but it is rather complex and haven't found a similar post, so please be kind! I think my issue is rather unique, so I'll try to explain as best I can. I'm ...
2
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0answers
77 views

DHCP Failover works but no DNS available

I have a DHCP failover (load balance) configured. DHCP failover works but the clients are not getting any DNS entries. We have 2 DNS servers using AD-integrated zones, and the failover is between ...
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3answers
40 views

Can the firewall prevent the DHCP to give an address, how to fix this?

I am not getting an IP in the subnet 10.0.0.0/24 where the DHCP is working and should serve an IP, I am getting instead only an IP in the subnet 169.254.0.0/16(link local address) that is probably ...
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0answers
25 views

DHCP, IP conflict on LAN (pfsense)

On my router I occasinally get a log with multible entries like this. It is a LAN with DHCP so I guess here should be no conflict at all... Is there a nature to this? May 11 09:24:36 220002 ...
3
votes
1answer
47 views

Reaching out DHCP relayed hosts

I have one primary server (DHCP) and one secondary (DHCP-RELAY). Majority of hosts are served from primary (wirelessly), however there are a few (wired ones) which get their IPs from secondary. ...
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64 views

Configure WiFi and LAN network to use the same Kerio DHCP server

We have a local network in the company: An Ubuntu server hosted for VPS. Kerio Control Appliance 8.5 installed on VPS as internet & DHCP server . WiFi modem connected to eth0 of Kerio. eth1 of ...
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0answers
28 views

Virtualbox vm lstp client login blank for lstp server on ubuntu 14.04 , what I'm missing here..?

I am trying to configure a lstp server ( ip of lstp server : 172.16.40.0 ) on a 64bit ubuntu 14.04 and check it network booting virtualbox vm (harddisk less vm) I configured everything according to ...
1
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1answer
42 views

Is it possible to bring down a network with DHCP discover?

When a DHCP server receives a DHCP discover message it broadcasts the offer across the entire network. If a malicious machine joined a network and somehow began spamming DHCP discover messages, would ...
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57 views

How to configure DHCPv6 and DNSv6 configuration in Ubuntu 12.04?

I'm planning to configure DHCPv6 and DNS server in my network. I would like to understand whether both DHCPv4 and DHCPv6 can be configured using isc-dhcp-server service? When i tried nslookup ...
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31 views

How to set up a simple Cisco ISG config for controlling internet access

First off, here is my config so far. http://pastebin.com/fV2NGCE2 I've gone through a few guides online and the 15.2s manual and the xe3 manual for Cisco's ISG (intelligent services gateway) and ...
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1answer
42 views

How to move company voip phones to a different subnet by modifying DHCP of a Cisco Switch?

Our company has replaced its old voip phones with new ones which are the NEC phones. We are done with the configuration part, and the phones are working fine. But I want the phones to be in a ...
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1answer
27 views

Why does starting openvpn client, then dhcpcd give different routing table than the reverse order? [closed]

I am connecting through a router in my home, and tunneling all traffic via openvpn through a remote server. When I first connect with dhcpcd, then start openvpn, my routes look like this (on a linux ...
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50 views

DHCP Server ignores DHCPDISCOVER request

Within a VPN I am trying to implement dhcp. I have the following setup now: DHCP Server (dnsmasq) is listening/should listen on a virtual network interface. The interface is configured as follows: $ ...
0
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1answer
73 views

Installing a new domain server on a small network without taking down the old one

I'm attempting to replace a windows server 2003 domain controller/dns/dhcp server on a small business network with a new machine running server 2012 without having to take down the old one until ...
2
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1answer
84 views

How to get the DHCP-controlled DNS domain name for my Ubuntu machines in a Windows network?

I've been going in circles for a while trying to figure this out. I have a number of Ubuntu machines (some virtual) on a Windows network. From a Windows machine, I can ping or nslookup the Ubuntu ...