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

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59
votes
5answers
49k views

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 ...
48
votes
6answers
5k views

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 ...
28
votes
3answers
71k views

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 ...
26
votes
7answers
80k views

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 ...
19
votes
4answers
48k views

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 ...
14
votes
1answer
9k views

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 ...
12
votes
7answers
13k views

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 ...
11
votes
10answers
49k views

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 ...
11
votes
6answers
13k views

Why is my router assigning the wrong address via DHCP

I have a WRT54G router that is set up to serve out addresses via DHCP. It correctly serves up addresses to every other machine on the network, including another PC, my macbook when connected via ...
11
votes
5answers
8k views

IP address alias assigned by DHCP

I would like to create several aliases to eth0, but have the addresses assigned by DHCP instead of being set to static IP's. Is this even possible? All the examples I've seen assign a static IP using ...
11
votes
1answer
7k views

Windows clients not using NTP server provided via DHCP

I have a network consisting mostly of Windows Vista and 7 clients and an Ubuntu server. The server provides both the DHCP and NTP services through dhcp3-server and openntpd. In my dhcpd.conf, the ...
9
votes
4answers
81k views

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?
9
votes
3answers
6k views

Unable to resolve .foo.local domain names

My workplace has an intranet with domain names like server01.foo.local, server02.foo.local, etc. I recently booted the Fedora 16 live environment to test it out and discovered that these domain names ...
8
votes
4answers
1k views

Does a router know not to hand out static IP addresses to other devices?

I set a computer on my network to use a Static IP address Shutdown the computer so its not on and not connected to the network Question: How does my router know not to hand out that IP address to ...
8
votes
4answers
8k views

Obtaining a DHCP IP address if static address is not available

I have seen some questions that are similar to my problem but not a good solution. Ex. User has a laptop and has a static IP address at the office. They also take the laptop off site where they also ...
8
votes
6answers
11k views

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, ...
8
votes
4answers
11k views

How to configure `eth0` to retry `dhclient` when unplugged and replugged?

I'm working on a linux gadget. I want it to get DHCP if I plug in the network cable after it has booted up already or if the network cable unplugged and replugged. One solution is to run a script ...
7
votes
4answers
3k views

What does static DHCP mean? Static Dynamic is confusing

I've found some home wireless routers/ADSL+ modems (ZyXEL 660) talking about Static DHCP, when refering to assosiating a specific MAC to an IP, but still serve the configuration over DHCP. Doesn't ...
7
votes
1answer
3k views

Preventing SSH RSA host key warnings for change of key vs IP address

I have a network with DHCP enabled, and also a computer that dual boots operating systems and has different SSH keys on each (and yes, I would like to keep different keys on each rather than copying ...
7
votes
4answers
6k views

dhclient and dhcpcd the real difference

I can't figure out the difference from just the man pages. I can see what is a daemon and one is a client, but what does that mean practically when using the commands? Also what is the difference ...
7
votes
4answers
12k views

Creating WiFi Access point on a single interface in Linux

I am trying to create a WiFi hotspot or an access point on my Linux laptop. I am using Opensuse Kde 12.3. I found out a software called hostapd which lets you create hotspot but it requires two ...
7
votes
2answers
2k views

WiFi cannot connect to internet in two router setup

I am struggling to setup my home network. I have the following setup, also shown in the diagram below (sorry for the MS Word screenshot!): My landlord has an ADSL connection, established by Router ...
7
votes
3answers
11k views

Accessing a router which isn't a DHCP server

I have a Linksys WRT54GL router with Tomato installed on it. My network configuration requires me to disable the DHCP server on the router. After disabling it, I do not know the IP of the router ...
7
votes
1answer
2k views

Can I add DNS but keep those provided by DHCP in OSX?

I'm trying to add an additional DNS entry in my OSX network preferences but I want to keep the DNS provided by DHCP. These show up in gray, but when I click the plus button below them, they disappear ...
6
votes
3answers
3k views

How to use dnsmasq with DHCP-assigned DNS servers?

TL;DR version: How do I configure dnsmasq to fall back to the DNS servers pointed to by the DHCP server on my LAN, to enable switching wireless networks? On my developer laptop I've recently started ...
6
votes
2answers
6k views

What is the “Alternate Configuration” tab in TCP/IP settings

As I know there is two choice for configuring a computer IP address in the network. Assigning a Static IP or obtaining a dynamic IP from a DHCP server. But what is the Alternate Configuration in ...
6
votes
10answers
21k views

Why won't a MacBook Pro running Snow Leopard obtain an IP address (DHCP)?

Background: I am trying to connect my MacBook Pro to a business grade network where I do not have access to reboot the server, switches, or router. Problem: The MacBook Pro (running Snow Leopard ...
6
votes
2answers
7k views

DD-WRT: DNSMasq expand-hosts not working

I have a Linksys router running DD-WRT (Firmware: DD-WRT v24-sp2 (09/08/09) mini). I have it successfully resolving the DNS names for my DHCP-assigned systems, but only when I fully-qualify those ...
6
votes
1answer
11k views

How to run a DHCP server on an ethernet port of a MacBook successfully?

I aim to have an ethernet switch on my MacBook ethernet port from which I will have several Raspberry Pi's connected getting their IP via DHCP, each will have a VNC server running on them for remote ...
6
votes
3answers
1k views

Why does my computer not always automatically request a new DHCP lease when switching networks?

I've noticed an interesting problem recently where my laptop will not automatically refresh my DHCP lease when changing between wireless networks. Instead, it will attempt to use the existing lease ...
5
votes
5answers
42k views

How can I tell if my IP is static or assigned by DHCP on Windows 7?

I don't know if my IP is static or assigned by DHCP. How can I find out which it is? I'm running Windows 7.
5
votes
7answers
25k views

How to assign a static IP with a linksys WRT54G2?

For all my googleing it appears the best you can do is tell your computer not to use DHCP; I cannot find a way to do this at the Access Point level. EDIT: This is not for port forwarding. This is ...
5
votes
3answers
10k views

DHCP Reservation vs Static IP address

So after browsing some websites, some people are telling me that static IP address is the best. But others say the DHCP Reservation is just as good if not the same. So what is better? Or are they ...
5
votes
2answers
8k views

What are the common router default DHCP IP address ranges?

I'm trying to find out what the default DHCP ranges are for common routers. Does anyone know?
5
votes
1answer
2k views

From my 192.168 box, how do I find 10.0 virtual machine on the same box?

I am running Ubuntu 12.04 and VirtualBox 4.1.12. I have created a Debian server under VirtualBox. For reasons I don't understand, DHCP grants my Ubuntu box 192.168.20.50 and my Debian VM 10.0.2.15. ...
5
votes
3answers
6k views

How to determine gateway address when going from DHCP to static IP address with Ubuntu

What's the proper way to determine the computer's gateway when going from DHCP to a static IP. Operating system is Mythbunutu with Ububtu desktop installed. I had previously been editing ...
5
votes
4answers
1k views

Self-assigned IP address

I sometimes have problems dropping IP addresses after changing networks and get stuck with a self-assigned IP that I cannot drop by hitting the renew "DHCP Lease" button on my Mac OS X.5 Leopard. The ...
5
votes
3answers
4k views

Where does “Client Name” come from in the DHCP client table on router?

I have a Cisco router. The firmware webpage has a tab the displays the DHCP client table. As the name suggests it lists all of the DHCP clients on the network. The first column in the table is the ...
5
votes
3answers
7k views

PXE Boot Server without DHCP, for many different computers?

I work at a helpdesk for a university where it is very common for us to reformat people's computers using XP, Vista, and Win7 CD's and DVD's. Of course, the discs get scratched and lost a lot. It is ...
5
votes
2answers
5k views

Wired connection periodically disconnects requires ipconfig /release and /renew to reconnect

I just got back into University and after a day of using the internet I suddenly was unable to visit other webpages even though I was still able to chat. I restarted the computer and the internet ...
5
votes
2answers
8k views

PC does not get ip address from router using wired connection

I have an ASUS WL-520GU wireless router with four LAN ports. When my laptop is running Windows 7, and I make a wired connection from the laptop to the router, the laptop does not get an IP address. ...
5
votes
2answers
1k views

What are the benefits of dynamic leased IP addresses in a home network?

I have a small network at home with a router, a printer, a NAS and 4 PCs. My router allows full DHCP management and I have set my router, NAS and printer to have static IP addresses (reserved fixed ...
4
votes
8answers
9k views

How can I change my public IP address?

I'm looking for a way to change my public IP address. You know, the one that other websites see. I know what I'm looking for is basically a proxy server, but I don't want to use a proxy for 2 ...
4
votes
2answers
6k views

Possible to ipconfig release/renew for only one nic?

I've got two NICs in my Windows 8 Pro (x64) box each connected to different networks. I would like to release and renew the DHCP lease for just one of the NICs. So far I can't find any way to do it ...
4
votes
3answers
4k views

Network is not connecting after startup automatically in Windows

After some perturbations with network drivers now I have a situation where the network is not connecting automatically after the boot-up. It indicates, that the connection is limited or no ...
4
votes
3answers
5k views

Add a static IP alias to a DHCP interface on Windows 8

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. ...
4
votes
6answers
24k views

DD-WRT serving additional DNS servers instead of just the router’s IP

I have a DD-WRT (using DD-WRT v24SP2-MULTI (03/21/11) std) router set up with DNSMasq to resolve certain domains to internal addresses and pass everything else thru. The router itself is configured to ...
4
votes
2answers
3k views

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 red that the ARP one is there for security reasons, others say it is for ...
4
votes
1answer
6k views

Getting 2 IP addresses on one network card, using DHCP

Given: A computer running Linux (CentOS 5.x), one network card connected to LAN switch, a second one to cable modem via crossover cable. This computer acts as a router/firewall/traffic shaper for the ...
4
votes
2answers
8k views

DHCP table in Debian

How to view all assigned ip addresses on a Debian DHCP server? It is usually easy to do on a standalone router through a web interface. How to do it with dhcpd in Debian?