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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Dynamic IP address to Domain

A camera when connected to a DHCP Network receives an IP address. Using IP lookup I find the IP address of the camera. Then I type the camera IP address in a browser - it shows a website (index.html) ...
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1answer
571 views

Why does a DHCP-provided DNS IP address becomes a static one in Windows 10?

I have a Windows 10 machine which often changes networks and retrieves its IP configuration via DHCP. Since an indefinite moment in the past it started to set its DNS as fixed, despite the fact that ...
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11 views

What is better, DHCP on Cisco Meraki MX64 or Windows Server 2012R2? [on hold]

I'm new to the Cisco world and I would like some advises. Currently I'm configuring a Windows Server for a small bussiness (less then 50 users). Normally the Windows server would have the AD, DNS and ...
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36 views

dhcpd class match on hostname or mac address

We are running DHCPD 4.1.1-P1 on a RHEL 6 server. Currently we have 1 class defined for deny purposes. We now have a need for a class match to allow all devices that match a variable and deny ...
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32 views

libvirt: set hostname using dhcp in virtual network

I've configured a host-only (aka private) network for a group of VMs on a CentOS 7 host. I've created static leases in the DHCP section for the virtual network. The IP address is getting set ...
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28 views

DHCP on Meraki MX64 or Windows Server 2012R2?

I'm new to the Cisco world and I would like some advises. Currently I'm configuring a Windows Server for a small bussiness (less then 50 users). Normally the Windows server would have the AD, DNS and ...
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1answer
24 views

Set Internet Access for VLAN + Default Gateway + DHCP Client

I have a question that make my mind so bussy. I would appreciate if anyone guide me about this. So let me explain: Firstly consider We have bellow devices: Devices: 2 L2 Managable Swiches 1 ...
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24 views

How to configure isc-dhcpd-server to update reverse zone without client pre configuration?

I'm trying to set up isc-dhcpd-server from ubuntu 16.04 (4.3.3-5ubuntu12) to configuring heterogeneous network with ubuntu, windows, macos, other ip devices. I'm already setuped bind to store ip ...
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62 views

Why does a DHCP4 client not respond to the DHCP Offer from a DHCP server?

An extremely simple DHCP server works reliably with Windows 10 PCs and Android devices. It receives DHCP Discover from a client, replies with DHCP Offer, then receives DHCP Request from a client. ...
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27 views

Do DHCP server messages have to be sent from port 67?

I know DHCP servers receive messages (e.g. Discover, Request) at port 67. Can a DHCP server send responses (e.g. Offer, ACK) to port 68 from a port other than 67? I thought the client should not ...
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9 views

What data is stored in DHCID RR by rfc 4701 (in lay terms)?

To understand what is going on my dhcp server I need to understand what is stored in this record that idenities my dhcp clients. I have long read this standart. But cannot understand. In lay terms I ...
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29 views

Configuring DHCP for two separate subnets in same lan

I have 192.168.1.0/24 network right now. As number of users growing this is getting difficult to manage them. Hence I added one DHCP server in network with two scopes. One is for 192.168.1.0/24 & ...
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211 views

Wireless Client (Laptop) unable to connect to domain (windows server)

I have established a server in the office using Windows Server 2008 R2 and Active Directory. And then created several users in Active Directory Users and Computers. The PC users can successfully join ...
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1answer
32 views

Wireless devices are detecting DHCP/DNS but Wired are not

I set up a server hosting AD, DNS, and DHCP. My wireless devices are successfully contacting the server and receiving an IP address, but my wired devices are not connecting. I have 2 virtual servers ...
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20 views

Setting dnsmasq_config_file with Puppet managed OpenStack installation

Our OpenStack installation is rolled out with Puppet. We use the excellent puppetlabs-openstack module for that. Due to the slow turnover cycles we are still stuck with version 5.0.2, right now we ...
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35 views

Interface being deleted

I have a cluster consisting of CentOS6.5 and CentOS7 virtual machines. I've come across an issue where the network interface, eth0, is being deleted for reasons unknown and I'm looking for help on how ...
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1answer
62 views

How can I clear the DHCP GUI in OSX Server? Ghost clients in the building

I have a few client machines showing up in the network (not only in Server.app but also in various logs), which have "Computer Names" (Bonjour names in Apple-speak) which I don't recognize, but ...
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1answer
16 views

DHCP Relay agent not working

I'm quite new to the DHCP Relay Agent thing, but it seems to be best solution. So here is the deal: DHCP server (Win 2012R2) is at 10.0.3.1/24; ServerB (Win 2012R2) is at 10.0.3.3/24 and 10.0.2.1/24. ...
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40 views

DHCP client not getting IPv4 address from a DHCP server

I configured a DHCP server on a VM in VirtualBox. This machine has 2 network adapters, enp0s3 - NAT (from where I have my network connection) and enp0s8 - Internal Network (intnet). DHCP server is ...
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27 views

Abnormal DHCP Android device traffic cannot be identified

Hi Serverfault community members. I've been trying to identify the source of an abnormal broadcast traffic generated by some Samsung Android devices with no success, so I ask for your help. I have ...
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1answer
20 views

DHCP snooping on distribution layer stops cliens on access from getting ip address

Here is my topology: sw1(gi0/1 trusted port)->sw2(gi0/1 trusted port)->core-sw(gi0/1)->DHCP_server at the beginning i only configured sw1: ip dhcp snooping ip dhcp snooping vlan 18 int ...
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39 views

Why a computer in one VLAN cannot get an IP address from a DHCP server in another VLAN?

Can anybody please explain as to why a computer in one VLAN cannot get an IP address from a DHCP server in another VLAN by default? Why is there a need for a DHCP Relay Agent or an IP helper, they all ...
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24 views

Dhcp Classless Static Routes hook error

I have a dhcp server that hands network information to vms of mine. It works fine for centos6,7 , and debian 7 clients. However it fails for Debian 8 and Ubuntu 16.04 clients. For the ones where it ...
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44 views

Can a computer on one VLAN acquire DHCP from another VLAN?

Can you please explain what needs to be done in order for a computer in one VLAN to get an IP from a DHCP server in another/different VLAN? (Yes if something is done and no if that something is not ...
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45 views

How can I block access to the internet for static addresses?

I have a router on CentOS 7 which provides access to internet for several IP addresses, which are reserved at DHCP server. Other hosts are blocked. If someone put static address from the reservation ...
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36 views

DHCP renew fails with multiple subnets on same link

Our network currently consists of 3 subnets on the same link: 1.2.3.0/24 is the global subnet 10.1.0.0/16 is used for NAT (because there are far more than 200 clients) 192.168.0.0/16 is the "guest ...
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20 views

Restricting Source IP of DDNS Updates

Goal: For a non-Microsoft DHCP server to send dynamic DNS updates on behalf of non-Microsoft domain clients. Question: With a particular zone in a Microsoft DNS server configured for "Nonsecure and ...
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1answer
54 views

Multiple interface Red Hat 6 ISC DHCP Server sending Incorrect PXE next-server

My setup: Red Hat 6.7 isd dhcp server 2x networks connected (A and B) One DHCP pool configured on Network A When I had this server set up on a single network ("A") it worked fine, now that I added a ...
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66 views

DHCP unable to deliver offers over routers

I have the following network: PCVLAN10 -> SWITCH_LAN1 -> ROUTER_LAN 1 -> ROUTER_LAN2 -> SWITCH_LAN2 -> DHCP(ROUTER) I have set up subinterfaces on the routers, and allowed trunking on VLAN 10 on ...
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85 views

How to get the connected wireless router's DHCP server not of another router's in the same network?

I have two internet connections and three separate wireless routers on the same network. The two dlink routers are serving one internet connection and the speedport the other internet connection. My ...
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38 views

DHCP Configuration

Our network ran out of IP address on the current local subnet, so my boss requested our service provider to change our subnet from /24 to /20, it will give us more than enough IPs to assign to the ...
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32 views

How can I configure systemd.network DHCP server to distribute IP routes?

From this question I understand that I can use DHCP to distribute classfull routes. How to do it with the DHCP server embedded in systemd.network (if possible)?
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53 views

how dhcpd handles static IPs vs DHCP reservations

We have a RHEL 6.7 server for DHCP. I am needing some clarification on how dhcpd handles network addressing when someone wants a permanent IP address. Here is a sample config from one of our servers. ...
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29 views

DNS is not enabled for Local Area Connection

On Windows Server 2008 R2, I have an error saying DNS is not enabled for Local Area Connection with a red circled "X" by the right. In DNS I have Error 4013. I have restarted the Server, the static ...
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63 views

Traffic on eth0 despite denying it with iptables

Despite having an iptables ruleset which should not allow it - DHCP is working on eth0. Given the below information can anyone give me an idea of why? tap0 is not up (not that it should make any ...
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41 views

PFsense 2.2.6 static dhcp hostname blank

We are on pfsense 2.2.6 and we enable static dhcp for each mac address on each VLAN where dhcp is enable. DHCP is working good but when I enable static dhcp and leave the hostname empty and when I ...
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10 views

Unable to access VM after DHCPACK libvirt

The installation of a particular software makes my VM lose its connectivity. The point where it hangs is 2016-04-05 16:49:11.996 | Listening on LPF/o-hm0/fa:16:3e:b2:43:4c 2016-04-05 ...
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1answer
65 views

Does a Windows host correctly interpret dnsmasq parameters?

I have a network of Windows 10 machines served (DNS and DHCP) by a dnsmasq instance on a Ubuntu server (Ubuntu 15.10, dnsmasq 2.75). The setup basically works (dnsmasq provides addresses and manages ...
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1answer
25 views

Identical DHCP leases, excessive dhcp traffic

Fresh install of CentOS 7, removed dnsmasq, installed dhcp server, iptables, webmin, apache. This is school and lot of switches and wifi (bridge mode) AP's connected to this router One network - ...
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1answer
72 views

Best way to connect dual SSID / VLAN wireless to Watchguard firewall

I'm currently sorting out our network so we can have new wireless access points with dual SSIDs, one for internal use and one for guest use. These will be setup so each SSID is on a different VLAN. ...
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24 views

Search option in resolv.conf getting overwritten by prepend statement in dhclient.conf

I have setup a DNS server for my department which is running FreeBSD 10.2. It is currently connected to the campus internet and receiving its address via dhcp, so /etc/resolv.conf looks like this: ...
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1answer
60 views

Minimal requirements to firewall rules for running dhcpd server in linux container

I want to run isc dhcpd server in lxd (lxc) container. But it does not recive clients requests (DHCPDISCOVER, DHCPREQUEST) from clients without this rule: iptables -I FORWARD -m physdev ...
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24 views

Why was the previous authenticity of the host ignored?

I'm on Ubuntu 14.04 Desktop. I have just logged into other machine (Ubuntu 14.04 Server) using ssh in one terminal. I'm still connected. When I did scp in another terminal (opened earlier) to move a ...
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1answer
70 views

Windows Server 2012 Failover DHCP

I've been tasked with migrating from our current 50/50 scope resilient DHCP servers to new hot standby failover DHCP in Server 2012 R2. Built a test bed with the two DHCP server VMs and created a ...
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52 views

How to discard a DHCP request's old IP address (and provide a new one)?

I switched from a 192.168.0.0/24 network to 10.10.10.0/24. The addresses are provided by dnsmasq-dhcp. The switch went fine for all devices but one - a printer (called PRINTER). This printer was ...
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2answers
36 views

Cisco 1841 Router from STATIC to DYNAMIC Configuration

Basic PC-to-Internet Ethernet Configuration I'm trying to find the proper configuration in the IOS to have Fa0/0 = DHCP and Fa0/1 = STATIC-only, to allow packets from the STATIC side (inside network) ...
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1answer
30 views

DHCP removing existing DNS records when asked for leases and none are available

I'm having a problem with my Dynamic DNS and DHCP setup where clients requesting leases when none are available causes a cascading failure where existing clients have their forward and reverse DNS ...
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2answers
29 views

DHCP issue with Cumulus and ESXi

So my switch has Cumulus Linux running on it and I have ESXi running in my network. So my main network is on 172.22.0.0/24 which has my my esxi. The networks I want esxi vms to run on is ...
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17 views

Linux clients get DHCP, Mac and Windows clients does not

I'm a sysadmin for a smaller computer lab (~40 clients and ~2000 users). We are, since this fall, seeing some weird issues with DHCP within our network. The server receives a DHCP discovery from the ...
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64 views

Microsoft DHCP only for reserved addresses

We are runing a Windows Server 2012 DC which also takes care of DHCP. Now I want to limit the DHCP-Server to all the reserved hosts to prevent DHCP leases for foreign devices as laptops, ...