Dynamic Host Configuration Protocol (DHCP)

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3answers
72 views

how to monitor network traffic in small office [on hold]

We have a small office with around 30 systems . We have an internet connection connected to a router , The router is connected to a gigabit switch . All the computers are connected to that switch. ...
1
vote
1answer
14 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
votes
2answers
49 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 ...
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0answers
16 views

how i can use DHCP for outer users safely

i have one 2k08 r2 DHCP-server serving multiple Vlans at work. is it safe to use the same DHCP-server to serve guests from outside company and also using it at living area (combined to the company) or ...
1
vote
1answer
15 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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0answers
22 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
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 ...
0
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0answers
44 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 ...
-3
votes
1answer
57 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
43 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
votes
2answers
73 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
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0answers
25 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 ...
-1
votes
1answer
33 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
votes
0answers
87 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 ...
1
vote
1answer
54 views

Why are DHCP leases not included in DHCP Log?

Running Windows Server 2008r2. DHCP Logging is enabled (Server Manager, Roles, DHCP Server, , IPv4, Properties, General, Enable DHCP Audit Logging). In the DHCP event log (Event Viewer, Custom ...
1
vote
1answer
42 views

Is it possible to bring down a network with DHCP discover?

When a DHCP server receives a DHCP discover message it broadcasts the offer across the entire network. If a malicious machine joined a network and somehow began spamming DHCP discover messages, would ...
0
votes
1answer
65 views

calculate reserved ip address based on mac address

Is it possible to calculate ip address based on mac address for isc-dhcp server? For example: 'aa:aa:aa:aa:aa:x' => '10.10.10.x' I have following in dhcpd.conf: subnet 10.10.10.0 netmask ...
0
votes
1answer
63 views

How to configure DHCPD server to bind static IPv6 address by DUID?

how can i configure the server to make static record DUID - IPv6 ? For example i have such DHCPv6 request: Client Identifier Option: Client Identifier (1) Length: 7 Value: 31303030303133 ...
0
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0answers
158 views

CentOS DHCP server supporting multiple subnets on a single NIC

I understand that what I am asking has been asked a million times already. I think I have read just about every post I can find on the subject yet I still cannot get this to work. I have a DHCP ...
1
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0answers
110 views

2008R2 DHCP Server Becomes Unresponsive

At the end of 2013, our single Windows Server 2008R2 DHCP server started becoming unresponsive once every week or so. The server itself was up, but the DHCP server was unresponsive. Attempts to ...
1
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1answer
35 views

1-dhcp server for 2 separate network

Debian Server Setup (wheezy) 1 - eth0 - Connected to INTERNET 1 - eth1 - LAN 1 (Network 1 : 192.168.100.0/24) 1 - wlan0 - Access Point (Network 2 : 192.168.200.0/24) /etc/network/interfaces auto ...
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votes
1answer
152 views

XenServer 6.2 DHCP Setup

I have a XenServer 6.2 running on a dedicated OVH Server. For this dedicated server I have 2 additional IP blocks. Whenever I setup a new VM (mostly CentOS 6.6) i have to skip the network ...
0
votes
1answer
14 views

Change DHCP on server 2k3

Ok I am trying to mess with our dhcp settings on our domain server because at this point we kinda have competing dhcp servers between the router and the server. (Long predates me and I have finally ...
1
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0answers
43 views

dhcp relay with failover to local service

I'd like to set up a dhcp server which normally relays to a central site, but has a pool of addresses to hand out if the link to the central site goes down. I'm using isc dhcp server on Debian, but ...
0
votes
1answer
334 views

configure a dhcp server to serve two different scope on the same subnet with multiple interfaces

Ok, so here I am with a pretty complicated problem on a Debian Wheezy server I have three interfaces : eth0, eth1 and wlan0 on a single server, eth0 will act as a gateway for eth1 and wlan0, I have a ...
0
votes
2answers
527 views

SCCM 2012 R2 OSD pxe-32 : tftp open timeout

I have SCCM 2012 R2 standalone primary site on windows server 2012 and i have Cisco dhcp server i configured the distribution point for pxe boot to work with osd i added boot images and configured ...
8
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3answers
1k views

Why does a DHCP server need a static IP address?

I'm experimenting various network setups using VMs. When I setup the DHCP role on Windows Server, it requires a static IP. I am having trouble understanding why this is necessary from a technical ...
1
vote
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 ...
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votes
1answer
18 views

DHCP server with 2 NICd

I have windows 2012 r2 x64 standard server. That server has 2 NIC nic1 gather IP from LAN1 nic2 - here i need run dhcp for LAN2 (black network) This server will have firewall which will be use ...
0
votes
2answers
92 views

Duplicate MAC address, can be blocked?

Let's say we have DHCP server and provided MAC filtering system. Can we blocked the next spoofed MAC address? The next device will not be leased any IP address. Or normally it is already blocked by ...
3
votes
1answer
182 views

GPO to Configure DHCP Options

Our environment has approximately 15 Domain Controllers that also provide DHCP functionality to their networks. We have discovered several to have incorrect DNS settings. Their are providing incorrect ...
1
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2answers
95 views

SBS2011E + WS2012 + split-scope DHCP + site-to-site hardware VPN

Bit of a newb when it comes to this but I'm giving it a go and, so far, things work but I hope I'm doing it in a correct manner and a couple of little hiccups... HQ has a SBS2011E DC (DC1) that ...
1
vote
2answers
178 views

How to “segregate” non-domain DHCP clients with Windows 2012 R2?

I search a way to prevent network access to devices not belonging to our corporate Active Directory domain. Some people connect their personnal laptops to our corporate network, and some of them ...
2
votes
1answer
69 views

2 client classes sharing the same subnet range

basically I would like to achieve the followings: using only one subnet different types of user sharing this subnets creating 2 pools accordingly an user class called "l2vpn_user" if matched by MAC ...
2
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0answers
74 views

How to associate a DHCP pool or subnet with declarations for a class

I have the following working configuration for ISC DHCP server 4.1.1, which hands out fixed addresses to registered clients. Some of those clients are configured for PXE booting (for FAI and SCCM). ...
2
votes
1answer
57 views

Are MAC ID passed via DHCP Relay

Do MAC ID pass through dhcp relay? Even if its connected on the WAN from the internet? So if the DHCP Server is on the WAN of the router and connected to a DHCP server on the internet is it passed?
2
votes
1answer
2k views

Cant deploy images with WDS: PXE-E16: No offer received

I am currently playing around with a WDS lab environment on a virtual 2012 R2 server, which is patched to the latest available update-level. This server is running the DHCP server role and has two ...
2
votes
1answer
75 views

DHCP Relay behind two router

If i have a DHCP Server above two routers and a cleint computer below and the client computer is connected to a router with DHCP Relay, will dhcp pass through those two routers? Here is an example ...
0
votes
1answer
153 views

Backup and Restore DHCP

Today our Windows Server 2003 server is running DHCP to serve all clients with IP addresses. We have installed a new Windows Server 2012 R2. Now i want to move the DHCP from the 2003 server to the new ...
1
vote
2answers
1k views

Windows Server set multiple Gateways and metrics

I would like to configure my DHCP Server (Windows Server 2008 R2) so that it assigns to each host two gateways. The client should use the gateway which is closer (less number of hops). I can do this ...
0
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0answers
225 views

Why need DHCP Relay (Watchguard) inside the Trusted network?

I run a small network that looks like this: { Win 2008 server , desktops , Wifi AP} -> Switch -> Watchguard XTM21 firewall (the Switch is connected to the XTM's Trusted interface ; the XTM ...
1
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0answers
258 views

One server has multiple IP address leases but just one adapter and no dhcp reservations?

One of our servers' has multiple (10) DHCP Addressleases and I don't know why. The server itself has only one adapter and even if I execute ipconfig /all I only see one IP address defined. Even in the ...
2
votes
1answer
963 views

How to find out IP address held by a Windows DHCP client yesterday?

We have a Windows Server 2008 with DHCP server running. I can see the current leases and reservations, is there a way to see the status of yesterday (or at least what IP a particular client had ...
2
votes
0answers
52 views

DHCPD does not allow filename option with a colon in it

For some reason, tftpboot does not work with a colon in filename parameter: group { filename "node7:linux/pxelinux.0"; host machine_7a { hardware ethernet 02:01:02:02:01:11; ...
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votes
2answers
109 views

how to get a connection between Windows and Linux without an existing DHCP server

Scenario: In general a ubuntu machine (called server) runs in a network and gets an IP from it. Due to testing, sometimes a windows machine (client) is physical connected to the ubuntu machine ...
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votes
2answers
97 views

How to force the network machines to get the ip from a DHCP server? [closed]

How can I force all the network machines to get the IP from the DHCP server and prevent them from manually editing the network configuration. There are both Linux and Windows machines. The DHCP server ...
0
votes
1answer
740 views

VSS DHCP Jet Writer Experiences Errors During Backup with WBADMIN

Summary My standalone physical server is running Server 2012 R2 Foundation. Two separate backup schedules exist, both using Windows Server Backup. I'm getting VSS errors from the DHCP Jet Writer ...
1
vote
1answer
2k views

Windows Server DHCP import/export scopes using netsh.exe

We have Windows Server 2008R2 as domain controller with DHCP Server functionality. Task was to make reserve server on remote site in case of failure of main one. The reserve one will be running ...
13
votes
2answers
9k views

What are the possible issues in using very short DHCP lease time (< 1min)?

We have a network setup for a demo, which lasts about 15mn. Our DHCP server is configured to assign ~ 100 addresses (max number of simultaneous connections or our AP) ... but since people might come ...