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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2answers
30 views

Will computers connected to a switch have a different ip?

I want to set up a network switch with several servers connected to it that must be port forwarded. Please refer to the below diqgram for my setup: ___Computer 2 | ...
0
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1answer
37 views

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.
0
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1answer
936 views

VLAN & WiFi & DHCP with Cisco SG200

I'm trying to configure a small business network with one Cisco SG200-26, a Linux server and two TP-Link TL-WA801ND. I have set up the APs to have two different SSIDs, Public and Staff, and have ...
1
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1answer
2k views

Retrieving kickstart and other .img file in pxe remote installation in CentOS

I am trying to installation CentOS through pxe tftp installation. Installation starts but it fails to download image files from the http server. but file are accessible on the http server. Logs from ...
1
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0answers
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 ...
5
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4answers
733 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 ...
0
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0answers
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 ...
1
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1answer
1k views

Client see Windows Deployment Services but still get “selected boot device failed” error

Like the title says I can't Windows Deployment Services working. The client laptop has an ethernet IP address of 10.0.4.94. On the secondary DHCP server I've set option 60 to PXEClient, option 66 to ...
1
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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
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1answer
26 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 ...
2
votes
3answers
710 views

/32 subnets on Ethernet via DHCP

Is it possible to assign to an ethernet host via DHCP a subnet mask of only the host itself, e.g. 192.168.1.123/32? Do common operating systems support this kind of configuration? I'd like for the ...
0
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1answer
1k views

How could I fix “No subnet declaration for restart (0.0.0.0)”?

I have a DHCP service installed on my distribution, Backtrack 5 R2 (ubuntu 10.04) and it was working fine, but when I began to configure DNS it suddenly stoped working, how can I make it work again?? ...
2
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1answer
4k views

IP served by OpenVPN doesn't take ipp.txt into account

I'm facing some troubles right now with an OpenVPN server an former colleague set up (I'm not too into it ATM). We're using OpenVPN for a private network of ~200 clients (to be more specific, only 15 ...
1
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2answers
5k views

Issue with RHEL7 and disabling NetworkManager

Okay community, let's see if we can figure this one out, cause I'm out of answers. Where I work I am setting up a bunch of RedHat Enterprise Linux servers. There is a collection of RHEL6 and RHEL7 ...
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votes
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 ...
2
votes
2answers
4k views

CentOS 7 is not setting my gateway from DHCP

I have a Minimal Install of CentOS 7. I have disabled the Network Manager as I want to setup my network the "old school" way. systemctl stop NetworkManager systemctl disable NetworkManager ...
1
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1answer
1k views

Windows 2012 DHCP Failover: Scope refuses failover config Error: 20044

I have a scope configured on a Windows 2012 DHCP server (primary in a hot standby config) with two Cisco Vendor class options. I've added the Vendor class options, identically, to the standby server. ...
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1answer
26 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 ...
1
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2answers
175 views

Unable to locate DHCP Server

I am supporting a mixed Mac OSX and Windows environment. There is a rogue DHCP Server which seems to be providing the IP-addresses to Mac systems on the network. I have used both ZenMap and Wireshark ...
58
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11answers
124k views

How do I find if there is a rogue DHCP server on my Network?

What's the best approach towards determining if I have a rogue DHCP server inside my network? I'm wondering how most admins approach these kinds of problems. I found DHCP Probe through searching, ...
5
votes
8answers
4k views

What equipment do real ISP's use? [closed]

In a dormitory of 550 residents, people often mistakenly set up DHCP servers for the whole network by plugging in their private Wi-Fi routers wrongly. Also recently, someone mistakenly configured ...
2
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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 ...
0
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1answer
1k views

dnsmasq(as DHCP server) isn't working in KVM+libvirt envirmont

I'm using dnsmasq as DHCP server in VM environment. But It didn't working. I disabled basic DHCP feature in libvirt. <network> <name>default</name> ...
4
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0answers
43 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 ...
0
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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 ...
1
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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 ...
1
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2answers
2k views

Juniper SSG5 DHCP IP Pool is full. Unable to offer IP address to client

hope we have some Juniper guys around, I have configured a Juniper SSG5 as our main firewall/router the DHCP server set on interface bgroup1 to have a rang from 10.10.10.76 to 10.10.10.210 All ...
2
votes
2answers
20k views

Domain connection shows as “unauthenticated”

I have seen various different questions for this problem floating around but either the circumstances arent the same or the solution doesnt work so thought i would post it to see if anybody has any ...
0
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2answers
13k views

Query a Windows DHCP server : find MAC from hostname

From my computer, I want to query my DHCP server to find a specific mac adress. I want to enter the hostname to search, and getting back the Mac address. Something like : netsh dhcp server scope ...
1
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1answer
2k views

Kickstarting an Ubuntu Server 10.04 installation (DHCP fails)

I'm trying to automate the network installation of Ubuntu 10.04 LTS with an anaconda kickstart and everything seems to running except for the initial DHCP autoconfiguration. The installer attempts to ...
7
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7answers
15k views

Command line program to test DHCP service

Is there a simple ping-like command to test whether a DHCP service is running on a network? ...on Linux
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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 ...
0
votes
1answer
2k views

Disable LDAP service in CentOS 6.3

What command needed to disable LDAP service in CentOS 6.3. I tried: authconfig --disableldap but it doesn't work. I am trying to run ISC-DHCP in my machine but it always shows Not searching ...
1
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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. ...
0
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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 ...
1
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1answer
43 views

Workstations connected to SBS 2011 can not connect to “http://connect/” and are getting frequently disconnected or kicked off of the shared drives

Small Office, there are 7 computers and a server running SBS 2011. 2 workstations are not currently bound to the server, because after recently reinstalling windows 7 on them, it was discovered that ...
0
votes
3answers
1k views

Gateway gets stripped from DHCP Reply through OpenVPN tunnel

I have a bridged OpenVPN setup. This is my server config: port 1194 proto udp dev tap0 ca /etc/openvpn/easy-rsa/keys/ca.crt cert /etc/openvpn/easy-rsa/keys/server.crt key ...
0
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0answers
23 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 ...
0
votes
1answer
19 views

Group reservations in Windows Server 2k12 R2 DHCP

I am moving a mixed network from a Linux DHCP server to a Windows 2012 DHCP. Because of some of the applications our Linux users need, we need to specify different DNS servers for Linux and Windows ...
2
votes
1answer
430 views

Windows Server 2012 DHCP and OSX Devices

I've recently put together a small office network (around 20 devices) with an attached machine running Windows Server 2012. Our gateway router provided by our ISP was pretty useless and started ...
2
votes
1answer
1k views

Windows 7 Client gets incorrect IPv6 Prefix Length

I am currently setting up IPv6 and DHCPv6 for Server 2008 R2 on my private network for testing. I was able to get DHCPv6 to work by configuring a static, then setting up the scope. I was also able to ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
2
votes
2answers
653 views

How to make sure clients use only the IP assigned via DHCP

We want to limit the users Internet usage on a daily traffic basis but not the local network bandwidth. Our users are on different platforms (Windows, Android, IOS), therefore it is not possible to ...
0
votes
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
votes
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 ...
0
votes
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 ...
1
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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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2answers
100 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 ...