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Questions tagged [dhcp]

DHCP stands for Dynamic Host Configuration Protocol and is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol.

The Dynamic Host Configuration Protocol (DHCP) is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol. DHCP allows for computers to be configured automatically to communicate with each other over an IP network without the need for manual setup by a network administrator.

The implementation of DHCP relies on a DHCP server to hand out network configuration information to DHCP-capable clients that request an IP address (and other information required or useful in communicating with other devices on an IP network). In addition to an IP address, common configuration information served over DHCP includes a default gateway, subnet mask and DNS sever(s), though there are many more possible configurations that can be sent out using the DHCP protocol.

More in-depth detail on DHCP and its implementation can be found at Wikipedia.

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How to prevent or block other DHCP servers?

Is it possible in a managed switch such as a 3com 4500 or a HP Baseline PWR-Plus type switch to block DHCP from being served through specific ports, or all except 1 port? I have a DHCP server for example plugged in to port 1, I need that to continue…
Scott Szretter
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How do I convince Dell blades to PXE Boot

Scenario: Brand new Dell M610 blades. Connected to the network with a 10GE uplink into a Dell PowerConnect M6220 blade switch. DHCP server evidently working, as everything else boots / gets addresses fine. TFTP server working fine. Can't seem to get…
Tom O'Connor
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Why is dhclient issuing a unicast DHCPREQUEST every ~15 seconds instead of at T1/T2 timers?

I am running a CentOS 6.2 server as my gateway and firewall, while also providing some internal services. This is a setup I have had for years using various hardware and distributions (redhat based). Recently I have ran across an internet…
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How do I MAC filter with DHCP server

I want to Only allow certain MAC addresses to get a IP from my DHCP server, currently I use dnsmasq and I rather not change dhcp server but I'm open to other software aswell. However, I need to be able to set static IP addresses for specific MAC…
Joelbitar
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Exclude IP address from DHCP pool

Is there a way to exclude a single IP address from a DHCP pool? For various reasons I have a machine that I can't reconfigure or move off the network (let's call it a printer). It has been hard coded with address x.x.x.50 and my DHCP pool is…
James Butler
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Preventing duplicate DHCP server on network

How can I prevent a duplicate DHCP server on a network from interfering? Is it possible? I am not asking for any actual scenario that is happening, just curiosity. In my apartment complex there is a network and internet provided, someone caused…
Sonny Ordell
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Why would Windows Server not respond to DHCP DISCOVER?

My network was working just fine and I broke it. There is a Cisco 1711 router which was configured to hand out DHCP leases to the client PCs. I have a domain controller (Server 2008) on the same network that I wanted to take over the DHCP role. I…
Nic
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Debian 10 Buster can't renew DHCP as client, when IPv6 is disabled

After I upgraded Debian 9 to 10 Buster server lost network connection after 24 hours since reboot, I think problem is it can't renew IP address from DHCP server. In /var/lib/dhcp I see the file dhclient.eth0.leases with expired date inside. This…
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Changing OpenVPN DHCP pool

I have a config at the moment which is working almost fine until some clients connect, the server starts to kick the clients off from the server or something like that. As I have checked every clients get a good IP address and there is no IP address…
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Ubuntu - dhcp server 'not configured to listen on any interfaces'

I'm at my wits end on this one; I have tried for hours to get this to work, but I'm stumped. Hope one of you can help. :-) I'm trying to get dhcp3-server to work on Ubuntu. It's installed, and setup correctly to run in rc2,3,4,5.d runlevels. On…
Jez
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How would a PCAP filter look like to capture all DHCP related traffic?

As I understand it, for IPv4 I would need to capture UDP port 67 and 68, ARP, ICMP echo request and reply, and for IPv6 I would need UDP port 546 and 547, all DHCP-related multicast addresses, ICMPv6 neighbor discovery. I want to capture DHCP…
Mathias Weidner
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Multiple DHCP uplinks - How to ignore DNS and default route on all but one?

A multi-homed box needs more than one uplink to be configured for DHCP. It needs to ignore default-route and DNS for all but one DHCP uplink. There is a similar question here [ Debian interfaces file - ignore gateway and dns entries from dhcp ], but…
Nils Toedtmann
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How does a router get its IP address assigned?

I understand how a device connecting to a router (e.g. 72.73.74.75) gets assigned a local IP address (e.g. 192.168.1.5) using DHCP. BUT, how does the router itself get the IP address assigned from the ISP in the first place? How does it make sure…
Justin Hou
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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 did not have PXE services or WDS installed. I…
Colyn1337
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Force DHCP Reservation Updates to Secondary DHCP Server in Windows Server 2012 R2

I have setup and configured two DHCP servers on my private network in load balancing mode as outlined in the following technet article: http://technet.microsoft.com/en-us/library/dn338979.aspx Both VM's are running Windows Server 2012 R2. Since the…
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