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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1answer
2k views

Aliased network interfaces and isc dhcp server

I have been banging my head on this for a long time now. There are many discussions on the net about this and similar problems, but none of the solutions seems to work for me. I have a Debian server ...
14
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4answers
2k views

Windows DHCP Server - get notification when a non-AD joined device gets an IP address

SCENARIO To simplify this down to it's easiest example: I have a Windows 2008 R2 standard DC with the DHCP server role. It hands out IPs via various IPv4 scopes, no problem there. WHAT I'D LIKE I ...
3
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1answer
896 views

pfSense - DHCP Relay

I have 3 pfSense boxes acting as routers on a single subnet (172.22.12.0/26). Router A - 172.22.12.1 Router B - 172.22.12.17 Router C - 172.22.12.33 I want Router A to be the only DHCP server. ...
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1answer
2k views

Assign two static IP addresses to one mac address

Can Isc-dhcp-server give two static ip addresses to one mac address? I have several Genexis terminals in my network. Each terminal have two interfaces, one for public traffic and one for a management ...
0
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2answers
106 views

Controlling 2 DHCP servers in one network

In my customer network, we have 2 DHCP servers. One is fully controlled by me and another by a different vendor. I want to make sure a set of devices (my devices) when connected, should get IP address ...
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0answers
1k views

CentOS 6.4 - Cant get an IP from DHCP

I have a Ubuntu and CentOS system running on XenServer. The Ubuntu Box gets and IP from DHCP no problem. The CentOS will not take a DHCP but a static address works fine. [root@XenCentOS ~]# service ...
21
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3answers
2k views

How do I protect a low budget network from rogue DHCP servers?

I am helping a friend manage a shared internet connection in an apartment buildling with 80 apartments - 8 stairways with 10 apartments in each. The network is laid out with the internet router at ...
2
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0answers
206 views

ISC DHCPD IPv6 for multiple interfaces

I want to assign multiple IPv6 to a server with multiple NIC. As IPv6 RFC defines, each server has a unique DUID that can have one of the 3 formats (LL, LLT or enterprise). And each NIC has an IAID. ...
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2answers
648 views

DHCP serving has stopped working

Something happened in our server room over the weekend that had me in the office late Saturday night replacing two switches. After powering down both racks, I have an issue where none of the computers ...
0
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1answer
52 views

Changing from router DHCP to Server DHCP [closed]

I want to setup a Linux DHCP server instead of a router based DHCP. I'm guessing that I will need to turn off the router DHCP, but keep the router as the gateway. I think that the BCAST DHCP requests ...
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1answer
362 views

Using DHCP on virtual servers (ESXI) [closed]

I am setting up a small lab with 5 virtual servers running on VMware ESXi 5. The servers are: Network Services server (CentOS 6.4) LAMP server (CentOS 6.4) File server (CentOS 6.4) Zimbra mail ...
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0answers
84 views

BOOTP on Juniper 4200 stack works one one subnet, not another

I have a Juniper Stack that connects vlans 10,11 and 50. 10 is servers, 11 is desktops and 50 management. Bootp is redirecting DHCP requests to a AD box on 10.x just fine for 50 vlan, and worked well ...
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2answers
376 views

DHCP split-scope using Windows 2008 and Windows 2012 servers

Can I configure DHCP split scope using our current Windows 2008 server with DHCP, and a new Windows 2012 server which I have installed DHCP on?
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3answers
281 views

How to get machines to use a DNS without a fixed IP, which does not appear in the DHCP lease? [closed]

I have some machines on a network. This network has a DHCP server - which I have no control over, and no DNS server, i.e. the DHCP lease refer you to some ISP's server and do not serve IPs for local ...
1
vote
3answers
543 views

Windows 2008 Domain - DHCP on Server vs Firewall

I currently administer a Windows 2008 domain network with DHCP running on the DC. Clients obtain addresses dynamically and servers are assigned static addresses. In the case that the DC fails ...
0
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1answer
485 views

DHCP over PXE fails, but in the OS it works - with configured (R)STP

I'm trying to PXE-boot desktop-machines to install a new OS over the network, but it isn't picking up an IP address via DHCP during boot. When an OS is already booted on the machine, it is working ...
0
votes
2answers
941 views

how to disable RRAS on windows 2008 r2 pre-reserving blocks of IPs

I have a problem where one of the DHCP scopes has exhausted its scope of IPs. Investigating, I found that a couple of the window 2008 r2 servers were reserving blocks of IPs for RAS running on the ...
0
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1answer
94 views

Private DHCP through a switch using two eth interfaces?

Right now, I have an Scientific Linux blade connected to the internet on eth3, and connected to a 48 port Cisco switch on eth2. This Cisco switch is connected to the eth2 of 24 blank blades (which are ...
1
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0answers
178 views

How to send several instances of the vendor-specific options to a DHCP server using dhclient?

I need to send vendor-options to DHCP server using dhclient (ISC). I've added following lines in the dhclient.conf: option dhcp6.vendor-class code 16 = {integer 32, integer 16, string}; send ...
1
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1answer
219 views

What determines which of a DHCP Relay Agent's IP addresses are attached to relayed requests?

I have a vlan with multiple IPs set, and a helper-address: vlan 15 ip helper-address 172.17.1.11 ip address 172.17.5.254 255.255.255.0 ip address 172.17.51.254 255.255.254.0 All relayed requests ...
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1answer
73 views

Hi, I have 3 dhcp servers like dhcp1,dhcp2,dhcp3 in my LAN. If client send the request for ip, which server will respond & offer the ip address [closed]

I have 3 dhcp servers like dhcp1,dhcp2,dhcp3 in my LAN. If client send the request for ip, which server will respond & offer the ip address
5
votes
1answer
12k views

VLAN tags not shown in packet capture (Linux) via tcpdump

I am adding a tagged VLAN onto eth0: #ip link add link eth0 name eth0.20 type vlan id 20 This results in: #ip link 2: eth0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc ...
1
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1answer
56 views

Server connections not connecting when switching to Static IP

I have a Centos 6.4 based VM, and I'm running Virtualmin on it to host my personal site. The problem is that by default, the OS is using DHCP, even though at router level (virtual router defined ...
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3answers
1k views

Linux server not receiving default IPv6 route over PPP link

I'm replacing a pfSense router in a remote office with a small linux device, running Debian. The router only has to handle very basic iptables / DHCP and VPN facilities. It is configured so that the ...
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votes
1answer
42 views

Server between our office network and the internet, as wireless router and ssh tunnel [closed]

We have a small office network that today is behind a normal router connecting us to the internet. We have a web based system on the internet and we have some admin tools on it that we want to lock ...
1
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2answers
216 views

IP Alias and port bridging

The situation is that I have an Ubuntu box with multiple ethernet ports, which I'd like to behave as if connected to the computer through a switch. I can achieve this easily with a bridge. In ...
0
votes
2answers
133 views

multiple (required) dhcp servers causes network problems in public library

A client of me asked me for helping with a network problem. The client in question is a public library. The problem: The library provide wireless internet access to the guests via an all-in-one ...
1
vote
1answer
84 views

Multiple DNS mappings for a host via DDNS

I have a network in which DNS is automatically updated with a record for hosts when they get an address via DHCP (isc-dhcp-server & Bind configured with DDNS updates). The DHCP server is ...
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votes
1answer
101 views

Where can I download the dhcpd3-server source code? [closed]

could you tell me where I can find the source code for dhcpd3-server? I know I can find the ready packages for Ubuntu/Fedora but I need to download the source code so I can..study it Thanx in advance ...
0
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2answers
208 views

DHCP is assigning existing static ip

I have some devices such as QNAP NAS drives and a computer that is not part of the domain connected to our network. I have assigned a static IP to these devices. Sometimes I find that the windows DHCP ...
0
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1answer
3k views

Hyper-V: Guest external internet access

Following setup: Host machine has 1 physical NIC Host OS = Win Server 2008 R2 (hosted in data center) Guest OS = Win Home Server 2011 Network setup basically as described here or here. Goal: ...
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1answer
54 views

DHCP and static IP

I have a server that dishes out IP addresses from 192.168.1.100 to .254. I then have a linux client that must be assigned on 192.168.1.150 for a few days (this is done in the eth0 network script. If ...
0
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1answer
306 views

Can't obtain ip-addres from my DHCP server

I can't obtain a ip-addres from my dhcp-server and it's going trough a firewall (pfsense), The firewall(pfsense) and DHCP server are two virtual machines on my physical server(ESXI). As rules i use ...
1
vote
1answer
87 views

DHCP server not assigning IPs - Linux (CentOS)

I am having a main issue with the DHCP server. It is not assigning IPs and the dhcp.leases file is increasing in size as it is logging multiple entries for same IP. Started and stopped the service ...
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votes
2answers
102 views

I turned off server 2012 which host my dhcp server but computers on the network still getting ip addresses

I have a DHCP server installed on Win Server 2012 which is turned off right now, but my computers still can establish online connections with the IPs previously received from the DHCP server. I tried ...
0
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2answers
44 views

Avoid connect 2nd DHCPs on 1 LAN [closed]

I have a LAN network using Draytek 2910 with DHCP. The network goes through 20 different rooms. At first everything is working good. Suddendly the network keep losing IP addresses every 30 t0 60 ...
3
votes
1answer
2k views

Understanding DHCPv6 Stateful Solicit message

I have been reading the full RFC 3315 and trying to generated spoofed nodes to ask for IPv6 address. (only for practice) Right now, I have a Ubuntu with wide-dhcpv6-server (the DHCPv6 server), one ...
0
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1answer
987 views

Debian hangs on startup (NFS Common utilities: statd)

I am trying to configure my debian 6 machine to use DHCP. I have modified the /etc/network/interfaces to only contain: auto eth0 iface eth0 inet dhcp But when I reboot it hang at NFS Common ...
2
votes
1answer
569 views

determining gateway ip in dhcp server in case of relay agent existence

I've got a situation where i have two subnets. (Say subnet 1 and subnet 2). ` My DHCP Client is configured inside subnet 1 (net id : network id 10.1.1.0) My DHCP Server is configured ...
0
votes
1answer
2k views

Configure DHCPD with assigned IP address and gateway on different subnets for KVM [closed]

I have a dedi with an IP range of 123.123.123.1/24, the problem is the gateway address: 111.111.111.254 and it's on completely different subnet. I have already setup a bridge and KVM virtualization. ...
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1answer
1k views

Can I see DHCP options on my network from a windows client? [closed]

Is there anyway to see the DHCP options configured on the server from a windows client (win 7) with no login / admin access to the server?
2
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2answers
3k views

Inconsistent dynamic DNS update behavior

After having upgraded a Windows Server 2003 Active Directory Domain to Server 2008, and upgraded client PCs from Windows XP to Windows 7, I'm seeing inconsistent dynamic DNS update behaviour. Two ...
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votes
1answer
36 views

AD Server Connection Probem

Ok so i have a Linux server handling the DHCP, and FTP server i have and Network Shares. Then i have a Server (Windows R2) with just the AD. None of the client computers can connect to the Domain. The ...
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votes
1answer
170 views

DHCP-defined local DNS address isn't responding [closed]

I set up a bind DNS server on 10.0.0.2 on my network. named.conf looks like this: options { directory "/var/named"; pid-file "/run/named/named.pid"; auth-nxdomain yes; ...
0
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1answer
95 views

Trying to install new wifi router, continually losing its gateway, sometimes crashing entire network [closed]

So, I'm trying to set up a buffalo router with dd-wrt loaded stock, If I leave the settings alone, the router loses its default gateway each time, and the router admin back-end is never accessible ...
1
vote
1answer
323 views

How do I resubnet my network [duplicate]

Our DHCP is running out of addresses. I cannot extend the range and would like to resubnet. Right now our addresses are: 10.1.24.1-254 255.255.255.0 Would I change the subnet to 255.255.254.0 ? ...
1
vote
1answer
94 views

Client doesn't get new IP when switching between subnets/locations

So here is our setup. We have 14 locations each with its own subnet and router. The routers at these locations have DHCP relay enabled that points back to our central server that is running DHCP. ...
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votes
2answers
1k views

Domain Computers cannot access internet [closed]

I have my own domain that i created not so long ago and i'm just now setting it up. I've been having some problems even from the past on my practice domains. None of the domain or any computers that ...
0
votes
1answer
570 views

Cannot ping gateway

I replaced my aging fileserver with a new server running ESXi 5.1 and migrated my fileserver in a virtual machine running on it. Now I have the following problem with this VM: I'm getting the ...
2
votes
1answer
415 views

DHCP Server Issuing NAK when servicing multiple subnets

We currently have 3 VLANs setup in our network. On our DHCP server (Windows 2008) we have 3 scopes created for the 3 separate subnets. Our clients can't seem to pull addresses on the subnets, except ...