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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3
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1answer
775 views

On Windows 2008 R2, how do I back up DHCP if the DHCP .mdb database is always busy?

I get this from my backup software. C:\WINDOWS\system32\dhcp\dhcp.mdb : The process cannot access the file because it is being used by another process. C:\WINDOWS\system32\dhcp\j50.log : The ...
8
votes
1answer
10k views

dhclient: What does “RTNETLINK answers: File exists” Mean?

I wanted to update the DHCP lease of an Amazon EC2 instance, so I executed the following command: user@host:~$ sudo dhclient Following that, the system's DHCP lease is updated successfully updated. ...
1
vote
0answers
594 views

DHCP offer is unicast but DHCPACK is broadcast

My DHCP server broadcast DHCPACK 0xffffffff . it is not working on layer 3 dhcp relay agent . as it can not forward this broadcast message to my client. can any one help me from exactly the broadcast ...
1
vote
1answer
159 views

CentOS 6 DHCP server configuration

I have a CentOS 6 server running on a virtual host. The IP address on this host get assigned through DHCP host and another interface has an static IP ( a test network). I want to setup an private DHCP ...
3
votes
2answers
807 views

Assign fixed IP address via DHCP by DNS lookup

Preface I'm building a virtualization environment with Ubuntu 14.04 and LXC. I don't want to write my own template since the upgrade from 12.04 to 14.04 has shown that backwards compatibility is not ...
0
votes
3answers
2k views

Superscope DHCP leases and configuration set up

Hello I wanted to see if someone could help with a network problem I am having. Right now we have a super-scope and scopes of 192.168.50.1 and 192.168.51.1, as of now both are activated but only ...
2
votes
1answer
1k views

How to statically configure DNS servers on a Cisco router when the WAN interface uses DHCP?

I have a Cisco router (model 887VA, IOS 15.4) used to connect a LAN to the Internet via ADSL. The WAN interface uses DHCP: interface ATM0.1 point-to-point ip address dhcp I need the router to use ...
2
votes
1answer
93 views

Routing DHCP traffic over the internet

i'd like to know if it's possible for the internet to be between a DHCP server and the network it's "assigned" to? so basically, something like this: -------------- ------------- ...
1
vote
1answer
166 views

Is there a way to use Bind9 $GENERATE directive for rDNS of ranges bigger than /24?

The $GENERATE directive of bind9 makes it possible to autogenerate the reverse mapping for a range of IPs what is really helpfull for reverse dns of a dhcp range. But it seems that the $GENERATE ...
1
vote
0answers
32 views

failing to configure a dhcp scope under Oracle Virtualbox

I've got a problem configuring a link between WS 2008 and Windows 7 both running as virtual machines (under Oracle VM 4.2.something). Static addresses do well, with both ping 192.168.1.2 (client) and ...
1
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0answers
194 views

pfSense + Squid, Windows 2008 DHCP

I recently installed pfSense and Squid3-dev on a spare machine. It is now connected to the network and Internet is working alright. The problem is that I can't get my users to go through Squid proxy ...
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0answers
227 views

ISC DHCP Option 82 binary-to-ascii for host declaration

If the relay agent encodes the option 82 as binary data (as is the case with Cisco and Brocade systems, at least), How can one perform this match: host 10-24-24-9 { host-identifier option ...
0
votes
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> ...
2
votes
1answer
242 views

Forwarding DHCPOFFER through bridged OpenVPN

Setup: host <---> OpenVPN-client with DHCP-helper <---> OpenVPN-server <---> DHCP-Server Except "host" everything is setup with static IP's and routing works fine. All stations can ping ...
2
votes
1answer
501 views

DHCP Administrators Group: No Permissions Granted on DHCP Server

I have added 'Group1' as a member of the DHCP Administrators group in my domain. Problem is, Groups and/or Users added to that group are not given permissions to view/manage the DHCP servers. How do I ...
0
votes
1answer
98 views

DRBL without modifying the DHCP: Possible?

Following up this question I'd like to ask: I use the company's network, but I have no access to the DHCP. I'd like to set up a DRBL server to be able to (re-)install a Linux image any time I want ...
0
votes
1answer
172 views

Adding Logic to DHCP Relay Agent

In our environment we have 3 DHCP Servers used for PXE booting. 1 - FreeBSD PXE 1 - Linux PXE 1 - Disked Imaging (clonezilla-like device) Each device requesting DHCP is on a separate subnet ...
2
votes
0answers
403 views

Windows DNS clients can't update PTR records, but can update A records (not ACLs) [duplicate]

I have clients configured via GPO with the following settings enabled: Dynamic Update Primary DNS Suffix Register DNS records with connection-specific DNS suffix Register PTR Records: Register I ...
1
vote
2answers
173 views

Dns: two pointer (PTR) with same IP resolve to different hosts

I have a Windows 2003 domain. DNS server and DHCP server run on domain controllers. Most workstations have DHCP enabled. Sometimes I have weird network problems and when I diagnose them I can find ...
2
votes
1answer
292 views

How to assign multiple IPv6 addresses with DHCPv6 to a single interface?

This seems to be possible based on the spec rfc 3315 page 23: Excerpt: The configuration information in an IA consists of one or more IPv6 addresses along with the times T1 and T2 for the IA. See ...
0
votes
1answer
209 views

Using DHCP, is it possible to obtain an IP address & MAC address for a cluster? [closed]

I know that DHCP assigns IP addresses, but does it also assign a MAC address? Is this a commonly used paradigm for cluster/cloud computing? Perhaps DHCP could be used to dynamically assign a new IP ...
0
votes
2answers
397 views

Clients getting server ip as their default gateway

I have a problem to solve. Scenario: LAN network 192.168.190.0/255 (1 server, 60 clients) Server Windows 2008 (server roles: mail server, print server, dhcp server...etc) 5 pxe-clients Debian ...
0
votes
1answer
212 views

Don't want isc-dhcp to ever reallocate reserved ip even if hosts is down

I've allocated ip's to some systems through dhcp and then made entries in dhcpd.conf for reservation so that these ip's are not allocated to other macs. But when the system with reserved ip is offline ...
0
votes
1answer
254 views

ISC DHCP Server scope error

Why am I getting the following error after modifying my dhcpd server config? option space definitions may not be scoped
0
votes
1answer
4k views

Windows Server DNS with non-Windows (Linux, Mac) Computers [duplicate]

How do I get my non-Windows (Linux, Mac) computers to properly register their IP address into my DNS server? Server Name: AD1 OS: Windows Server 2008 R2 Roles: DNS, AD, DHCP DNS SETTINGS Dynamic ...
3
votes
0answers
2k views

DHCP Server Not Offering to PXE Client

DHCP Server Not Offering to PXE Client BACKGROUND: I'm in the process of adding PXE services to an existing SCCM 2007 server. The SCCM server is separate from the DHCP server (Server 2008 x86) and ...
2
votes
1answer
174 views

Best Practices Analyzer on Windows 8.1 erroneously complaining about DHCP Default Gateway

I'm using Server Manager on Win 8.1 Update and have DHCP installed and running on a Server Core 2012 R2 domain controller. The BPA believes Option 3 (Default Gateway/Router) is not set. But it ...
1
vote
1answer
25 views

2008 DC DHCP Inquiry

We have a few servers mainly for SVN, File and nightly builds. We only use the DC for ALC. Currently, I'm using the Sonicwall's Built in DHCP to issue IP's to developers. Of course if the firewall ...
1
vote
1answer
888 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. ...
1
vote
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
vote
2answers
75 views

IP auto changed on Win2k8 VM

I'm having a problem with my Win2k8 virtual machine. After the virtual machine boot, it gets an IP address from DHCP. But later on, NTP makes a big time shift, so Windows automatically renew (in fact ...
2
votes
2answers
1k views

Windows 2012 DHCP server with 2 NICs

I have a Windows 2012 Server with 2 NICs running as a DHCP server. Each NIC is connected to a different subnet. I'd like to run DHCP service on each subnet from the same server. Is that possible? ...
-2
votes
1answer
215 views

how can I block internet access for non-domain computer windows server 2012 [closed]

Is there any GPOs that allow me to block an non-domain computers ? I tried to use IPAM for blocking an ip address but it does not work! What should i use ?
4
votes
1answer
1k views

Incorrect lease times from Windows 2012 R2 DHCP

Env: Two Windows 2012 R2 DHCP servers in active/passive (hot standby) mode serving one scope. Scope lease duration: 1 day. MCLT: 1 hour. Situation: New dhcp client gets IP configuration with a ...
1
vote
0answers
73 views

DNS Registration Using Non Windows DHCP

We are searching for a solution for our VPN users. We use a Fortinet SSLVPN. The Fortinet appliance issues DHCP to our clients. It is configured to have the clients use our internal Windows DNS ...
2
votes
1answer
310 views

Motorola SB6141 assigns 192.168.100.0/24 IP via DHCP when cable dies; can I prohibit systemd-networkd from using 192.168.100.0/24 addresses?

I have a Motorola SB6141 cable modem connected to a Linux firewall that obtains an IP via systemd-networkd's DHCP function. Every so often, the ISP will have issues, and for some reason, ...
0
votes
1answer
223 views

ISC DHCP - different subnet for specific mac addresses

I'm attempting to create a different subnet for a few specific mac addresses, and have my DHCP config set up as follows: authoritative; shared-network local { subnet 192.168.2.0 netmask ...
2
votes
3answers
468 views

DHCP Relay vs Multi-Homed DHCP Server

I'm sketching out a new network topology and I'm unsure of how to solve the issue of DHCP between two VLANs. 10.50.2.0/23 will hold the majority of our users, corporate wifi, printers etc. ...
2
votes
1answer
94 views

How to show other columns in Windows DHCP server?

In the Windows Server DHCP server, the only column that shows for "Reservations" is the "Reservations" column. That's not very helpful. It would be so much more helpful if I could see the ...
3
votes
1answer
698 views

Have DHCP use different scopes based on MAC address using Server 2012

I'd like my Windows 2012 DHCP server to give ShoreTel phones IP addresses from one scope, and everything else IP addresses from another scope. For example, I'd like to give phones IPs from ...
1
vote
1answer
641 views

DHCP troubleshooting - client timeouts

I have setup two ubuntu 13.10 serwers - one of them is in a small test network + two more clients, separated from our company's main network but connected to the Internet. This server is my testbox, ...
1
vote
1answer
613 views

Is there a limit to the number of DHCP scopes I can have?

Some context: Currently all devices in our remote sites are setup on 1 VLAN. We have 400 remote sites. A project wants to split our sites into multiple VLAN's which on the whole seems like a good ...
1
vote
1answer
44 views

DHCP frames (DISCOVER/REQUEST frames) have AutoIp address as source IPv4 address in Ipv4 header

In my TcpIp stack, I want to trigger AutoIp/LinkLocal and DHCP addresss assignemtn parellelly. But the response from the DHCP server is too slow. By the time I get a reponse from DHCP server the ...
0
votes
0answers
115 views

Edge firewall on Ubuntu, dynamic IP address, static DNS

We're setting up a software firewall, and one of the issues we're facing is that eth0 has a dynamic IP address. In /etc/network/interfaces we've got the following: # The loopback network interface ...
1
vote
1answer
530 views

Windows Server 2008 DHCP: Lease offered, but not accepted

My Windows Server 2008 should be configured to work as a DHCP Server in the Network. Therefore I setup the Role and configured everything. I have downloaded a tiny tool, that can show DHCP-Offers on ...
2
votes
1answer
586 views

DHCP Warning Sign Icon On Windows Server

I have a Windows Server 2008 R2 SP1 Domain Controller. I have the roles AD, DHCP, and DNS installed on this server. I noticed today that there was a warning sign on my IPv4 setting, but not on my IPv6 ...
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0answers
47 views

Windows Dynamic DNS Update Sequence

I'm trying to get the Windows DDNS update sequence straight in my head. Here's what I think happens: Windows Client == DHCP Discover Windows DHCP Server == DHCP Offer Windows ...
0
votes
1answer
90 views

DHCP Reservation being ignored in Windows 2008 R2

I have multiple scopes on my dhcp server. 192.168.10.x and 192.168.20.x I have reservations for certain mac addresses on the 192.168.10.x network. However occasionally they will pull 192.168.20.x ...
1
vote
1answer
685 views

How do I configure an ASA 5505 to pull a DHCP address from a bridged DSL modem/router?

I have a remote office that I am hooking up to our corporate network and this particular site has a centurylink adsl2+ router that I need to negotiate an rfc 1483 via DHCP connection across. The dsl ...
3
votes
2answers
2k views

Can you use WMI to determine if a connection gets its DNS servers from DHCP?

The DNS server search order for a network interface can be read from Win32_NetworkAdapterConfiguration like this in Powershell, or programmatically using .Net ManagementObjects: > $NICs = ...