Dynamic Host Configuration Protocol (DHCP)

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25 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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0answers
27 views

CentOS being used as DCHP server I need to have it service another network

I have added a new Vlan40 to a network & want the DHCP server to manage this one as well. currently It only manages a guest WIFI Vlan10. I have config. Vlan40 already & cant connect manually ...
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0answers
28 views

DHCP Server Dynamically Updating DNS on Other Server (Both Windows 2012 R2, No AD)

We have had a single Windows Server 2012 R2 server (with no Active Directory) running DNS and DHCP for our main network for a good few months with dynamic DNS updates from DHCP working fine. We have ...
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2answers
46 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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0answers
8 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 ...
3
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1answer
45 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 ...
4
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1answer
64 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 ...
0
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2answers
43 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
25 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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2answers
55 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, ...
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0answers
26 views

IPv6 Ping is unsuccessful when IP is obtained from DHCP server

I just faced this problem and it's driving me crazy. I have DHCP server for both IPv4 and IPv6. IPv4 works like a charm but the problem is IPv6. My client gets IPv6 (fc50::a9 to be exact) from DHCP ...
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0answers
19 views

dhclient bound to recorded lease even if no DHCP server is availabe

My Ubuntu machine is connected to switch and switch is connected to DHCP server(router).Now whenever DHCP server is down but link is available through switch it tries DISCOVER multiple times. But ...
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41 views

DHCP option 43 on switch Dell PowerConnect 5500

I have Dell PowerConnect 5524. Put SW01(config-dhcp)# option 43 hex f104ac1338fa got Option code 43 is not a valid HEX string. Strange. Its worked ok for me on Cisco device. Looking at User ...
0
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1answer
55 views

Possible to configure DHCP server to only hand out IP's to PXE clients

Is there a way when you are setting up a Red Hat DHCP server for PXE boot to ONLY hand out IPs to PXE clients? We already have a Windows DHCP server on the network (a server which we do not manage)and ...
0
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1answer
44 views

Does a Linux DHCP server have IP conflict prevention?

Scenario: We are migrating DHCP off our Cisco gear and onto a Red Hat 6.7 server. I am concerned about clients who will not release and renew for several days. Since the new server will not have any ...
0
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2answers
49 views

DHCP Reservation Without Knowing MAC

Is there any possible way to have a DHCP reservation set for a device which I do NOT know the MAC address for? In other words, is there any thing that might just be unique for a certain model of ...
3
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1answer
72 views

How to generate DHCP Decline scenario / packets

I have a dhcp packets sniffer, which needs to log if it sees dhcp decline response coming from client.I need to know the scenario where client can send dhcp decline response to dhcp server. I tried to ...
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0answers
118 views

Force isc-dhcpd to disregard client hostname in ddns updates

I have the following configuration of isc-dhcpd-4.3.1: ignore client-updates; ddns-update-style interim; subnet 192.168.128.0 netmask 255.255.255.0 { use-host-decl-names on; ...
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0answers
15 views

Can I use isc-dhcpd to provide an IP address based upon the request parameters?

I've got a dhcp request to be served with ISC-DHCPD: Gateway-IP 10.128.1.9 Client-Ethernet-Address 00:01:23:45:67:89 Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message ...
4
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1answer
209 views

DHCP: Create a scope within a scope

Before I joined the company I am currently working for, they set up a scope to encompass the 10.2.0.0/18 range of IP addresses (10.2.0.0-10.2.63.254). I was recently tasked with adding reservations ...
0
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1answer
73 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
49 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
138 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
159 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
63 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 ...
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1answer
24 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
125 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
19 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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0answers
107 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
119 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
89 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?
1
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1answer
86 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
709 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
102 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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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
56 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
49 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
21 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
131 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 ...
0
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0answers
105 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
237 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
votes
1answer
123 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
37 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
277 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
85 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
189 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
53 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 ...
0
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3answers
145 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
388 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: ...