Questions tagged [dhcp]

Dynamic Host Configuration Protocol; allows computers on the same network to automatically obtain unique IP addresses and other network configuration parameters.

Dynamic Host Configuration Protocol (DHCP) is an IP protocol that offers dynamic configuration of terminals, allowing automatic assignment of host IP addresses and other configuration parameters for network clients. DHCP is the successor of the simpler BOOTP protocol, which had more limited functionality. DHCP was first released as a standard in October 1993; the most current specification is given in RFC 2131 published March 1997.

Briefly, DHCP works as follows:

  1. A client sends a UDP packet broadcast (for all machines) with a DHCP request.
  2. The DHCP servers that capture this packet will respond (if the client falls within a range of criteria) with a packet which will include configurations with at least one IP address, netmask and other optional data, such as gateway, DNS servers, etc.
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How can I stop Mac OS X overriding my hostname when I receive a DHCP request on Snow Leopard?

Whenever I go on a network where the DHCP server assigns hostnames then it overrides the settings I've set for my hostname on my Mac in the "Sharing" section of System Preferences. How do I stop this behaviour from occurring and always have the same…
Mike McQuaid
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What is the difference between ARP binding and DHCP address reservation?

In my TL-WR1043ND I have these functionalities and both of them pair an IP address to a MAC address. What is the difference? I read that ARP is for security reasons, others say it is for Wake-on-LAN. I also read there is no difference, but in that…
totymedli
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How to force Windows 7 to ask for a "fresh" IP address from DHCP server?

I'm troubleshooting a certain issue with my DHCP configuration, and need my Windows machine to ask for a "fresh" IP address, so I can see which address DHCP server gives by default. When I do ipconfig /release followed by ipconfig /renew, Windows…
haimg
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Why is a router needed?

I‘ve been trying to figure out why a router is needed. I know a router can be used for DHCP and some other things, but I’m just thinking of networking with static IPs. So the following: Is it possible to do the following with static IPs: Modem ->…
Maxbit
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Why is Windows' default IP address 169.xx.xx.xx?

My Windows system got an 169.xx.xx.xx IP address the other day, and I fixed the issue, but why did Microsoft chose this address as the default? Why not 1.xx.xx.xx or 255.xx.xx.xx? Did one guy at Microsoft say Hey, pick a number 1 to 255....who…
Adam
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How does a router obtain its IP address?

So let's assume I connect a secondary router to my first. An Ethernet cable from one of the LAN ports to the secondary router's WAN. Now, how does my secondary router actual obtain its IP address? Is it through DHCP protocol or any other? The…
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How can I add additional search domains to the resolv.conf created by dhclient in CentOS

When my CentOS virtual machine boots it uses DHCP to get an IP address. It also overwrites resolv.conf with the DNS settings provided by the DHCP server. The DHCP server doesn't supply any search domains so I would like to get dhclient to put in a…
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Release/renew IP address via Terminal in OS X

I am looking to release and renew my IP address in OS X 10.4 (Tiger) using Terminal. Essentially, I need the OS X equivalent of Windows': C:\\> ipconfig /release C:\\> ipconfig /renew However, I need the interface to remain active during this…
Rupert
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6 answers

Add a static IP alias to a DHCP interface on Windows 8 (and above)

I have a Windows 8 machine that has only a single Ethernet port. It needs to use DHCP and also needs a static IP. Each IP is in a different subnet, and each serves a different, incompatible purpose. This machine must use DHCP because the site…
Warren Young
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How to request a specific IP address from DHCP server?

How to request a specific IP address from DHCP server? This question also touches the topic of DHCP address reservation in a router. Background: My home routers DHCP table only allows to create an IP address reservation of an assigned IP. It does…
leo
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Check if a DHCP server existing in my network using bash

using CentOS with static IP, Is there any way to determinate if a DHCP server running on the network using bash ?
Steve
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Why do most routers not include local DNS?

I need to change my firewall/router, and I'd prefer something with built-in DNS to resolve queries on the local subnets. I've got a mixed Linux/Windows system, often with only one computer turned on, and I frequently have problems resolving local…
EML
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How to find my DHCP server IP address via a command prompt in Windows?

Linux has easy commands to find the DHCP server IP address via a command prompt. Is there anything for Windows?
helloworld
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3 answers

Wrong IP address from DHCP client on Ubuntu 18.04

I'm experiencing a weird issue where my Ubuntu 18.04 (server) box gets issued a wrong IP address during boot from the DHCP server. Running dhclient after boot on the interface results in the right IP being added to the interface. The DHCP Server is…
NoMad
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Why is my subnet mask 255.255.255.255?

I have a modem which used for internet broadband and I got an IP address in the 'A' class 10.x.x.x and have netmask 255.255.255.255. What does 255.255.255.255 mean exactly? When I try to sniff with promisc mode, will this 'netmask' never allow me…
capede
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