Questions tagged [dhcp]

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Isc-dhcp-server not starting error: not configured to listen to any interfaces

I have installed Isc-dhcp-server and configured the files accordingly still it is showing the error that its not configured to listen to any interfaces. i have ubuntu 17.04 64 bit Interface file : auto lo iface lo inet loopback iface enp2s0 inet static address 10.90.90.5 netmask 255.255.255.0 gatew...
Ashish Ghodake
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DHCP server causes slow docker-compose operations

[Updated as I have found what is causing the problem; now I need to know why.] When I use a custom DHCP server on my network (a Raspberry Pi running Pi-hole) Docker projects on my system take up to two minutes to start. With networking on my computer turned off, or using the DHCP server on my cable...
Daniele Procida
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Loop DHCPDECLINE with Dnsmasq

Since some days I have infinite loop with dnsmasq DHCP… clients seems to refuse their IP that they were accustomed to having. We are talking about various clients, smartphones, PC, Mac,... I have only one DHCP server on my network. Only one subnet. Dnsmasq on 192.168.1.2, ISP router on 192.168.1....
Julien B
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Couldn't open device eth0: eth0: socket: Invalid argument

I am trying to use a simple DHCP client from GitHub. When I try to run this client it fails with eth0 MAC : C8:6B:00:E5:52:5E Couldn't open device eth0: eth0: socket: Invalid argument Any advices? Thanks!
Jebu Nato
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Filename string in DHCP/BOOTP/TFTP Read Request presenting extra characters

While building a basic Windows Image deployment solution (using WinPE and custom applications built in C#), I came across a problem of 2 Computers not being on the same subnet/IP segment (no static IP Address or DHCP Servers & DNS/Routing tables). To combat this I have written a basic but successful...
R.McInnes-Piper
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Windows PXE from virtual machine

I'm using Ubuntu as a dhcp server to PCs that will act as PXE clients and I want to serve those clients with a windows image from VirtualBox. This is for a Linux server running Ubuntu 16.04 and VirtualBox. The virtual machine running is a Windows 10. I aim to turn on the client and log in to Windows...
ChristopherP
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Detecting remote DHCP servers in .NET

Using Hyper-V I built a private windows domain which is fenced off from our main network. Ultimately I want to provision this domain for others to use for dev and test, so they can be domain admin. The domain controller is running the dhcp service (other systems in my domain have dependencies on dh...
Alex Peck
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DHCP request packet in c#

hi how can i send a dhcp request/discovery packet using c# to locate dhcp server any idea or snippet
Ehtsham
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Customized captive portal with external DHCP server

I am stuck in one issue for which I need your help on this. Actually its bit complex to explan about my situatuion but I will try my best. I am working on customized captive portal on arm processor board with embedded linux os. For which I need to run this captive portal server on my arm board. I go...
Dhruv Patel
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DHCP Client on Java, Can't send from IP 0.0.0.0

I'm trying to create a DHCP Client using Java. The client will send Discover, receive a Offer, send a Request, and receive an Ack. However, when sending the discver and the request UDP DatagramPackets, I need to send them from the IP 0.0.0.0 port 68 because, the point of DHCP is is to receive a usab...
Heartinpiece
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Building DHCP packet ( DHCPDISCOVER ) , packet structure

I'm trying to build DHCP packet in then send it via UDP ( '0xff.0xff.0xff.0xff', 67 port ). I have sucessfully connected to my DHCP server, but I have problems with first packet structure ( DHCPDISCOVER ) as I see, but I have built it from RFC && Wiki, and have checked all fields/size in bytes of th...
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iOS DHCP Request

I have observed from a wireless packet capture in my home network that anytime my iPhone device switches from asleep to active, and it is not attached to a power source, it sends a DHCP Request. I have validated this behavior with two different iPhones (with different iOS versions). I have also test...
Ioannis Pappas
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windows mobile force dhcp renew

We have several Windows Mobile 6.5 device deployed and a few of them will occasionally lose the ability to connect to the Internet. I've been able to reproduce the issue by switching from Wi-Fi to 3G over and over again. When I do recreate the issue, I get the message 'A DHCP Server could not be co...
GH23
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Android DHCP enabled disabled check

I wanted to know if there is any way to check programmatically in android phone whether DHCP is enabled or disabled. (Assuming its possible to disable DHCP through some way or dhcpd is not running)
neeraj
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Capture “netsh dhcp server show scope”

I need to capture the output from netsh dhcp server show scope which shows like: ============================================================================== Scope Address - Subnet Mask - State - Scope Name - Comment ============================================================...
BastianW
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How to request a particular IP address from the DHCP Server?

I'm trying to request a specific IP address from a DHCP server. My understanding is that I should be able to do this, if the server supports the DHCP_REQUESTED_IP request in the initial DHCP_DISCOVER message. Here's the code I have that isn't working: ip_addr_copy(&dhcp->msg_out->ciaddr , '0xc0a800...
user3171859
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List of all ip address (i.e devices) present in a local area network [closed]

I want to get the list of all IP addresses (i.e devices) present in a local area network. I don't want to use nmap, other networking tools. And also I don't want to ping each Ip address in a sub-net range and find live IP addresses? Is there any way by using C, C++?
Sanket
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How do you properly modify packet data in Scapy?

I’ve been using Scapy a bit and have been messing around with making packets. A problem I have is trying to specify certain data/options in packets. For example, I want to make a DHCP packet with option 60 but I don’t know what is valid input data to use for this. I know the packet should have a...
slyFox
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Scapy custom DHCP Option82

I'm trying to create a custom DHCP request with Option82 included but I'm not able to set the length of the suboption: ethernet= Ether(dst='ff:ff:ff:ff:ff:ff',src=get_if_hwaddr('eth1'), type=0x800) ip= IP(src='0.0.0.0', dst='255.255.255.255') udp = UDP(sport=68, dport=67) bootp = BOOTP(chaddr =hw, c...
Ignacio Verona
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Powershell - Set DHCP scope option to a predefined value

I am looking for a way to set DHCP Scope options on a scope so that when the predefined default value for the server is changed, it changes on the scope. When I use the MMC Snap In to turn an option on(and it has a predefined option value), this is how it works, so I know it's possible, i just don'...
Joshua May
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How to evaluate BOOTP chaddr by mac address?

In dhcp packet, a field means client hardware address, but it's not the same as mac address like 'fa:16:3e:6f:1a:9d'. If I have known a interface's mac address 'fa:16:3e:6f:1a:9d', how to evaluate chaddr by mac address? 0 1 2 3 0 1 2 3 4 5 6 7 8...
Wilence
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Detect hotspot usage

I need a develop captive portal for windows. What i did? I share my ethernet connection via wireless adapter with netsh wlan set hostednetwork mode=allow ssid=wifix key=pass1234 command. Detect connecting users (mac/ip pairing) with help of http://www.codeproject.com/Articles/20431/A-Small-DHCP-Serv...
Ercument Eskar
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How to change libvirt DHCP lease time

I use QEMU KVM on my Ubuntu 16.04 server for managing virtual machines connected via both bridge and NAT. I find that a VM connected via NAT requests DHCP request about every 20~25 minutes, and I want to change the DHCP lease (or request?) time longer. The system log of the host machine is like this...
Byoungheon Shin
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Setting domain name for ip address on pi (Apache, DHCP)

I set up my pi to broadcast it's own 'wifi' and I have an Apache server running on it. I used this tutorial https://learn.adafruit.com/setting-up-a-raspberry-pi-as-a-wifi-access-point I can currently connect to the network that the pi is broadcasting and go to the ip of the server on my phone and it...
DJSweetness
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Regarding DHCP Discover, Offer, Request, and Ack

In DHCP the initial Discover is a broadcast, but the remaining packets could be unicast. How is that possible if the client does not yet have an IP address?
as286713
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UDP socket unable to send packet to DHCP address

I have created simple UDP socket connection to send data between local network. The connection is of two types : peer to peer and group broadcast. Below is my class : Peer to peer server: public class CandyCaneUdpServer { Socket sck; EndPoint LocalEP; EndPoint RemoteEP; int port = 80; IAsyncResult o...
M. Ko
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Openvms dhcp server

Ok so I have OpenVMS VAX running under simh. I am attempting to setup the dhcp server, but I'm unclear on some of the config. I tried following along with the online docs, but no go. My clients aren't getting dhcp leases. Any help is appreciated, I'm still learning OpenVMS. My config looks like this...
Matt Morrow
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powershell Get-DhcpServerv4FreeIPAddress from end of range

We use reservations starting from the end of our DHCP scopes for printers. Get-DHCPServerv4FreeIpAddress starts from the beginning. Is there anyway to make it start from the end to the beginning?
Tuumke
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Extrat Data from DHCP Options List

I'm writing a Python script that pulls data from DHCP Packets. At the moment, a part of my output is just the list of from DHCP Options: [('message-type', 3), ('param_req_list', b'\x01y\x01\x01\x011\aaa_,.'), ('max_dhcp_size', 1500), ('client_id', b'\x01(\aaa\aa1A\aa1O'), ('requested_addr', '192.168...
dcode1
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Fetch lease time using IP address

I have an application on Windows CE 5.0 and Windows Mobile 5.0 where I am currently fetching the IP address using the following code: IPHostEntry dnsEntry = Dns.GetHostEntry(_host); foreach (IPAddress ia in dnsEntry.AddressList) { if (ia.AddressFamily == AddressFamily.InterNetwork) { _add...
Nethakaaru
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how can I prevent systemd-networkd from sending client identifier?

I have a machine with CoreOS 1800(or 1855) installed onto disk, and with following systemd-networkd config (there is only one network interface in the machine): $ cat /etc/systemd/network/zz-default.network [Network] DHCP=yes [DHCP] ClientIdentifier=mac UseMTU=true UseDomains=true Another notable th...
osexp2003
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Remote access jupyter notebook on Windows 10

My home network environment is using DHCP, the router uses D-link 600m, I want to make remote access jupyter notebook on Windows 10. Here are the steps I used: Windows network part: Open command: Enter ipconfig /all to get my private ip, subnet mask, default gateway. Go to the D-link settings page:...
yun Su
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Does DHCP client receive DHCP NAK if any of the parameters are wrong in DHCP Release?

I am building a dhcp client using C on Ubuntu 9.04. Now I send a dhcp release to the dhcp server, it sends no ack as expected. I was wondering if it sends any DHCP NAK if any of the parameters are wrong. There is one more problem. After sending DHCP Release my internet is still working. Also when I...
Bruce
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C# Poll multiple devices to determine IP type: Static or DHCP

Would like to know the c# code to actually retrieve the IP type: Static or DHCP based on a list of devices I will enter. Output to be viewed: Device name: IP Address: MAC Address: Type: Marvell Yukon 88E8001/8003/8010 PCI Gigabit Ethernet Controller NULL 00:00:F3:44:C6:00 DHCP Gene...
Charles Laird
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Unable to execute configuration on router through TFTP's python script

I am trying to use the ZTP approach to configure my router [R2]. My Ubuntu machine is both DHCP and TFTP server. Ubuntu [DHCP Server]: 16.04.5 LTS Cisco Router [DHCP Client]: 7200, version 15.2(4)S5 This is the python script- ztp.py. ztp.py is stored in /var/lib/tftpboot/ #!/usr/bin/env python3.5....
Prarthana Shedge
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Friendly name to acces my embedded device using USB/ETH connection

I have trouble to configure my network to access my device with a friendly name. Here is my situation: LAN ^ ----¦---- USB/ETH ------------------ ¦ PC ¦ ---------> ¦ Embedded device¦ --------- ------------------ What I'd like to do is using a friendly DNS name to access my devi...
morandg
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How to know all info DHCP returns?

If I am correct, DHCP also returns the SNTP address. Is there a command in CMD (DOS...) that is like a 'test' DHCP, meaning, that I can run it and will tell me everything that DHCP is returning? The IP address, the gateway address, the SNTP address, etc. Thanks,
Amarundo
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protecting /etc/resolv.conf from being overwritten when ppp0 is dialed up [closed]

I have an embedded system running a busybox distribution and for some reason i can't seem to find my dhclient.conf (http://www.freebsd.org/cgi/man.cgi?query=dhclient.conf&sektion=5) that would let me 'protect' resolv.conf wt but DHCP still works, how could that be? Also, is there another way to prot...
cerr
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Python dhcp client

I'm trying to learn how to directly (no libraries) send DHCP request from python on multi-homed machine (multiple interfaces). I've looked at pydhcplib, but still do not get it. This code send DHCP packet on specific interface (eth3 in my case - no IP assigned), but it sends with eth0 IP address. H...
Sergej Srepfler
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dhcp discover and offer messages not appearing

I'm dumping DHCP messages with wireshark and running dhclient interface_name to force the dhcp client reconfiguration. The first time I run dhclient I get all the usual messages: discover, offer, request, ack. From the second time on, I only get request and ack messages. Is the machine storing/cach...
Ricky Robinson

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