Dynamic Host Configuration Protocol (DHCP)

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1answer
188 views

DHCP: Create a scope within a scope

Before my employment at the company I am currently working for, a scope was set up to encompass the whole 10.2.0.0 range of IP addresses (10.2.0.0-10.2.63.254 to be exact). I was recently tasked with ...
0
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1answer
24 views

ISC DHCP Server “Dynamic and static leases present”

i have a problem similar to Fixed and dynamic IPs in ISC DHPD lead to double lease In my DHCP-Log I often receive warnings like Jan 21 10:20:56 dc2 dhcpd: Dynamic and static leases present for ...
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1answer
39 views

How to force DHCP server to provide a new IP? [closed]

I am using DHCP option 50 (client is an embedded device running eCos RTOS) to request a specific IP from the DHCP server (DHCP server is a built-in one with Windows 2003 server). First DHCP client ...
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2answers
102 views

DHCP scope not being created or created incorrectly [closed]

I'm trying to automate the creation of DHCP scopes, but have run into a tricky pickle. When I try to create a scope via the commandline like so: netsh dhcp server add scope 10.10.15.0 255.255.254.0 ...
0
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1answer
57 views

Enable DHCPv6 in dnsmasq to distribute fixed range IPv6 addresses but failed

Help wanted! I want to create a AP in my Raspbian PI. And i choose dnsmasq as the dhcpv4 and dhcpv6 server. However, my laptop can acquire IPv4 successfully but fail to get a IPv6. Why the dnsmasq ...
3
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0answers
56 views

Did I cause this DHCP failure?

I asked this here, it was requested that I move it to this forum instead. I have a question that I need some counsel on concerning DHCP and what may happen in a certain situation. I have a case ...
1
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1answer
22 views

DHCPD configuration by interfaces

I have two interfaces on a machine running Ubuntu 14.04 LTS. Which has two different interfaces namely eth0 and eth1. I need to give IP addresses to the clients by the interfaces. For example, Any ...
0
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1answer
24 views

dhcpd not offering reserved static IP returns unknown lease

typically when I reserve an IP for a MAC addr the device when booting up and requesting a dhcp address, will pick up the address I reserved. However recently the request looks like it comes in but ...
0
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1answer
17 views

How to interpret certain aspects of dhcpd logs

I have a DHCP server running on RHEL 6.6. I understand the process (somewhat) involving how the conversation goes from a protocol standpoint to set up a lease. 1 - The DHCPDISCOVER message. 2- The ...
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77 views

Why do our Windows 2012 R2 DHCP Servers lose reservations?

Windows takes our DHCP reservations, but does not know how to hold-on to the reservations. There is a history of this in Windows 2008 DHCP server, but the closest i could find for Windows 2012 R2 ...
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1answer
72 views

Server 2012 R2 Installed AD DC and Lost Internet Access

I am a developer and new to set up and server config... so please forgive my full lack of understanding. I am using a 1&1 Cloud Server with Server 2012 R2 Standard and am trying to set it as an AD ...
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2answers
55 views

Window Server 2012 with external DHCP

I have a Cisco router connected to a server with Windows Server 2012 fresh installed on it. What should I do to configure DNS if I leave the DHCP of the Cisco router active?
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1answer
61 views

CentOS DHCP server gives DHCPNAK upon DHCPREQUEST from client

I'm trying to setup a DHCP server on a virtualized host only network and I'm having some issues. Currently I'm only running two VMs one being the server and the other being the client both VMs are ...
7
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4answers
649 views

What happens if the DHCP server comes online after the client devices do?

If I have a Windows PC running a DHCP server. I expect it will take on order of minutes a few to boot. My network will have a variety of other devices from various vendors that will boot within ...
0
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1answer
80 views

How to change a DHCP's Scope Subnet - Windows Server 2012

I am trying to edit my DHCP Scope and want to Change only Subneting. The Reason I am searching for this is "I am using MAC Addresses in Policies". I have tried this solution ...
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0answers
13 views

Rotate Gateways between DHCP clients

On a small factory we have 3 Internet Fiber Optic Modems, about 40 computers, 1 server running windows server 2003 with one NIC, and an unknown number of cellphones The server has DHCP, Active ...
0
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1answer
50 views

dhcp server not assigning ip (centos 7)

I configured a DHCP server on centOS 7 (192.168.1.103) but it's not assigning an IP address to the client (using Windows as client). I am not getting any errors while starting/restarting the ...
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1answer
41 views

AD and DHCP in one server and have 2 diffrent network

I have two lans every one should use individual internet line : First is 10.10.10.0 255.255.254.0 topology: router connected to switches and have one sever connected to same switches server act ...
0
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1answer
20 views

Multiple DHCP Servers maintain multiple LOGICAL subnets

I have one physical LAN, but I have several distinct groups and each should have their own subnet. What this means is each server should be able to recognize its own clients and ignore the rest. ...
0
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1answer
93 views

DHCP in router with AD, DNS and DHCP in one Server

My Lan is working fine 5 switches connected to core switch and have a router, DHCP configured in the router, network 10.10.10.1, 10.10.11.254 -- Mask 255.255.254.0 -- d.g 10.10.10.1 (Router IP).DNS ...
0
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1answer
38 views

Extending IP-range

We have a problem with our IP-range. For the moment it is 10.0.0.1 to 10.0.0.254. Unfortunately it isn't enough anymore. So we wanted to setup a whole new scope on our DHCP server 2008. We want to ...
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0answers
70 views

What would cause DHCP Scope to thinks it's full when it's not?

Our DHCP server is not allocating addresses on one of our scopes. Statistics seem to show it's full: However, I can see there are only 88 addresses in use. I can't see any errors in the system or ...
0
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2answers
128 views

How to ignore unused network interfaces in dhcpd on Centos 7

I have a machine running Centos 7 with 8 network interfaces. I have three of those interfaces configured and running. I have configured dhcpd to handle the local lan interfaces. I get the following ...
2
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1answer
118 views

Microsoft DHCP server giving “old” lease to clients switching networks

I have 2 Windows Server 2012 R2 DHCP servers running in active/active load-balancing on one of the networks. DHCP requests from the other networks are DHCP relayed by the router to these DHCP servers. ...
0
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1answer
27 views

DHCP Authorization for Non-Windows Devices

I hope I can nail this question because I keep having a difficult time framing it properly. I'm looking at the feasibility of configuring switches to act as a DHCP server. In this article ...
3
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1answer
157 views

Windows DHCP Reservation Outside of Lease Pool

I am very sorry if this has been answered already. I found this post: DHCP Reservation However I wasn't sure if that was related to Windows or Linux DHCP server and I wanted to clearly state my ...
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0answers
62 views

Can I configure ISC DHCP to issue the same fixed-address to every client?

I have a handful of devices which are normally in separate networks (or perhaps not even connected to a network), and they use DHCP to get their IP addresses. Now I would like to run some script on ...
0
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1answer
139 views

ISC DHCPD class is not assigned

I'm trying to setup a boot server which only answers to devices which want to boot over the network. Depending on the boot rom, I need to deliver different boot images, the other settings are common. ...
0
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1answer
49 views

Why are DHCP request and acknowledgment messages broadcasted and not unicasted?

In 'Request' part of the DORA process, IP and MAC address of the DHCP server is known to the client (as the IP datagram sent in Offer has this information). So if the destination is known, why is the ...
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3answers
115 views

Can I use a router as a backup DHCP if the DC's are offline?

Server 2012 R2, Cisco RV082 This is for a very small network system where the DC's have to be shutdown periodically for a day or so. 2 DC's exist & are also acting as DHCP servers. It's a ...
0
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1answer
277 views

Event ID 1340 - DNS registration for DHCPv4 Client & DHCID has been denied (DHCP Name Protection)

Event ID 1340 warnings are consistently being logged on a Server 2012 R2 domain controller in the System log whenever Apple/Mac clients connect to the network. Here's a log example: Log Name: ...
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489 views

What happens when “Auto state switchover interval” is less than “Maximum client lead time” in DHCP?

I was wondering what happens when "Auto state switchover interval" is less than "Maximum client lead time" in DHCP? The question was raised after reading definitions of MCLT & ASSI: Maximum ...
0
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1answer
72 views

is it possible to use cobbler using windows dhcp server or without dhcp?

I want to configure cobbler in my network but my network already managing by a windows 2k8r2 dhcp server. Is it any way to configure without dhcp server ?
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86 views

How to disable or turn off DHCPv6 on Cisco 3939B router?

I am trying to set up a Windows Server 2012 R2 Essentials server properly. I would assume it could also apply to non-Essentials also. i.e. Standard. DHCP for BOTH IPv4 and IPv6 MUST be turned off or ...
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2answers
253 views

Can ping server one from client 1, but can't ping client 1 from server

I set up a router on my linux machine as described here. Now I can ping the server/router from my windows client. I can also ping my linux client from my windows client. But I can not ping the windows ...
0
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1answer
132 views

Error when configuring a failover DHCP: “The following scopes already exist on the partner server”

Server 2012 R2 I get that error message when clicking next in the Failover Wizard after specifying the partner server, but I don't understand it. In trying to research how to setup a failover DHCP ...
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0answers
89 views

Server 2008R2 DHCP Server not responding to Windows Clients

I have a Windows 2008R2 Server running DHCP Server, configured with a custom dll to assign IP addresses based on circuit IDs. Linux clients and pxe boots (using ipxe) recieve IP addresses from the ...
1
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1answer
427 views

DHCP post-install configuration error

Server 2012 R2 I moved my DHCP operation out of my Cisco router and into the server. In this case I used the domain server as I have a small system. DHCP seems to be working fine. However, Server ...
0
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2answers
277 views

Different subnet mask on router and DHCP server

ran into something funny today and am still scratching my head on why this happened. I was trying to increase the number of ip addresses available from my dhcp server by changing the netmask from /24 ...
1
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1answer
23 views

Obtaining the running config for dhcpd

Is it possible to obtain the current running config for dhcpd? I inadvertently wiped dhcpd.conf but have not yet restarted the service. It is currently assigning the correct IPs to my test ...
0
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1answer
56 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
32 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
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2answers
184 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
109 views

Windows DHCP server not discarding PTR records when an address is leased

Got the following setup regarding DHCP & DNS: Windows Server 2003 doing DHCP Windows DNS (different server)authoritative for the forward zone BIND DNS (on a UNIX server) authoritative for the ...
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votes
1answer
227 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 ...
1
vote
1answer
88 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
320 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
votes
1answer
55 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 ...
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1answer
38 views

How to use Server2012 as DHCP and on the same time Ubuntu Server as Gateway for the client Machines? [closed]

I want to use Windows Server 2012 R2 as a DHCP for the client computers with Ubuntu server acting as gateway to the internet. I am using VMWare WorkStation. Both machines are installed on it. Windows ...
0
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0answers
156 views

Windows 2012 DHCP ignores priority among server / range / class-policy / reservation options?

I am observing that the priority of DHCP settings in Windows 2012 DHCP server server options range options class options reservation options among which the ones listed later always override ...