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Questions tagged [dhcp-option]

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33 views

dhclient.conf - append to system hostname [duplicate]

I'm running a Raspbian on a bunch of Raspberry Pis. They each have a unique hostname set in /etc/hostname and the dhcp client correctly registers that name with my router. The problem I'm running ...
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37 views

DHCP Boot File Size Option

The description of the Boot File Size Option in RFC 2132 is not very useful: https://tools.ietf.org/html/rfc2132#section-3.15 3.15. Boot File Size Option This option specifies the length in ...
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25 views

How many DHCP Pad Option Bytes should be added?

RFC 1553 (DHCP Options) states: 3.2. End Option The end option marks the end of valid information in the vendor field. Subsequent octets should be filled with pad options. The code for the ...
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53 views

How to add more than 32 routes to isc-dhcp-server and separate them to 2 fields?

Is there any way to add long list routes to server? Actually now I can add only 32 routes because we have only 1 octet for them. After adding more than 32 routes I received "Malformed packet" by ...
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1answer
272 views

DHCP: Advertise DNS Server with port (not 53)

In my network I have a small docker swarm running several apps. Latest I tried to setup two new services offering DHCP with ispcpd and DNS with unbound to the network. Master of the swarm is a new ...
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1answer
185 views

DHCP snooping - my clients dont get ip from dhcp

Why the PCs don't get ip from Core switch Dhcp pool? without dhcp snopping there is no problem, but when i enable dhcp snooping clients stoping to get ip from dhcp. This is my topology: topology ...
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2answers
259 views

dhcrelay append option 66 and 67

I'm running a PXE Linux server in a VLAN. How is it possible to use [dhcrelay][1] to forward the DHCP requests to the main DHCP server and add the options for PXE with dhcrelay? I've tried something ...
0
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1answer
434 views

How can I configure DHCP server to issue the same fixed-address by matching with the client identifier in the discover message

I am able to config fixed ip address with hardware ethernet options, but i am trying to assign fixed ip based on client id(option 61) from DISCOVER message. I tried with below configs , but it doesn't ...
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1answer
1k views

Option 81 in DHCP

Just curious about this. When we enable option 81 on a DHCP network, the DHCP server will start updating the zone that comes along with the client's FQDN. Now, how would client will ever know its ...
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1answer
2k views

DNSMASQ Specify Port Number in dhcp-option=6

I run Ubuntu 16.04 LTS. I want to redirect DNS requests coming from some ip[-range] to another instance of dnsmasq on port 1995. To do so I added these lines in /etc/dnsmasq.conf file : dhcp-range=...
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2answers
3k views

Assigning a hostname of the fqdn assigned to a dhcp client with dnsmasq?

I'm aware that you can assign static DNS entry names by doing the following in dnsmasq.conf: address=/wiki.leerdomain.lan/192.168.1.200 ptr-record=wiki.leerdomain.lan/192.168.1.200 and then ...
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1answer
55 views

dhcpd daemon taking huge amount of memory and restarting with out of memory error

I have to configure isc-dhcp-server for 1 million clients which listens on 4094 vlan tagged interfaces, where each vlan interface is mapped to a subnet declaration. Therefore in total 4094 subnet ...
3
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2answers
61 views

Server 2012R2 DHCP & DNS Updates

I have the following DNS settings configured on an DHCP scope: My question is, will the DNS entry be made against the DNS server that the DHCP is configured to go against or will it update the DNS ...
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2answers
72 views

How do I configure Dynamic Host Configuration Protocol to return a FTP server's IP address along with the interface IP address?

Given that there is a dhcp client, a relay agent and dhcp server. There is also another ftp server. Requirement is that the client starts the DORA process and the server responds with IP address and ...
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0answers
523 views

OpenVPN: automatic proxy detection after connection is established

I have setup an OpenVPN server and an HTTP proxy server on the same host in cloud. I have also configured OpenVPN client on my desktop. I have also setup redirection rules on the cloud host to ...
4
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1answer
260 views

rfc 6939 support for dhcpv6 relay

isc-dhcp-server now supports rfc6939 as of version 4.3, and I would like to be able use it as it is quite nice to be able to just use the mac address to identify dhcpv6 clients. However, I can't seem ...
1
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1answer
934 views

dhcpd option 82 logging not working

We are implementing Option 82 in our network and I am just scratching the surface of how to setup my server. I have successfully created my first Option 82 ACL based on the agent circuit ID that is ...
3
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1answer
2k views

How to disable NetBIOS over TCP/IP on pfSense via DHCP

I have a pfSense applicance running version 2.x. I want to disable NetBios over TCP/IP via the DHCP Server so it is not activated on Windows clients. It's possible to do it with a Windows server but I ...
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0answers
2k views

DHCP server assigning same IP address even if Computer is connected in different VLAN

DHCP Server OS - Windows Server Standard 2008 R2 DHCP Client OS - Windows 7, Linux based OS etc.. I have configured DHCP Server on Windows Server Standard 2008 R2 with SuperScope. Let assume that i ...
4
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1answer
2k views

Does a Windows host correctly interpret dnsmasq parameters?

I have a network of Windows 10 machines served (DNS and DHCP) by a dnsmasq instance on a Ubuntu server (Ubuntu 15.10, dnsmasq 2.75). The setup basically works (dnsmasq provides addresses and manages ...
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1answer
1k views

classes declaration inside of subnets in isc dhcp

I would like to use class declarations based on a subnet scope, is that allowed? Or are all classes global scope? here is my dhcp.conf snippet: subnet 10.200.147.0 netmask 255.255.255.224 { ...
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1answer
381 views

Is `127.0.0.1` a special token for Ubuntu 14 LTS `resolvconf` when DHCP pushes DNS settings?

Dear Linux Graybeards, Is 127.0.0.1 a magic token for resolvconf in Ubuntu 14 LTS when using DNS settings pushed by DHCP? I'm using Ubuntu 14.0.3 (LTS) in AWS (ami-0f8bce65) with custom DNS settings ...
2
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1answer
224 views

Is it possible to set a dhcp option 77 value in vsphere as a config parameter so vNIC ROM (e1000/vmxnet3) uses it during PXE?

I'd like to set a dhcp option 77 string value in vsphere as a config parameter on a vm or vm template so that the vNIC ROM (e1000/vmxnet3) uses it during the DHCP part of PXE. My goal is to have PXE ...
3
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1answer
285 views

How did AirPort's DHCP “Welcome Message” work?

I remember that Apple's AirPort base stations used to have a DHCP "Welcome Message" feature, that would display a custom pop-up dialog when computers connected to the network. How was this ...
4
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0answers
1k views

VLAN ID over DHCP for Management Interface of Fortinet FortiAP

When configuring the FortiAP device it's desirable to configure the VLAN ID for the tagged management network. Accordingly to the manual it's possible to do so by "telnetting" to the FortiAP device ...
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3k views

pxe boot uefi ends with pxe-e16: No offer received - ip helper address in place

I've been deploying Windows with wds 2012 to clients running in BIOS mode forever, using wds 2012 and dhcp in the same network, but on different boxes. clients are in a different network and on the ...
3
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0answers
416 views

Can ISC-DHCP bind to Option 82 rather than Mac Addresses?

We use option 82 information to limit leases presently in ISC-DHCP using a spawn with statement for our billing subclass. This keeps a single household/business from obtaining more leases than they ...
0
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1answer
7k views

How can a dhcp client in linux can send the dhcp option 60 - specifying the vendor-id?

I am using fedora core machine. My linux- fedora core machine - client wants to send the dhcp option 60 specifying the vendor id to the dhcp server. Next, I want to read the dhcp option 43 send by the ...
2
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5answers
16k views

Cant deploy images with WDS: PXE-E16: No offer received

I am currently playing around with a WDS lab environment on a virtual 2012 R2 server, which is patched to the latest available update-level. This server is running the DHCP server role and has two ...
1
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0answers
503 views

Sonicwall L2TP Server is using a “phantom” internal DHCP server

Following a few articles on options 121 and 249, I'd like to push out routes to the L2TP VPN clients using the internal DHCP server on the Sonicwall. However, the Sonicwall seems to be using a ...
1
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2answers
2k views

ISC dhcpd dynamic bootfile-name. Is this possible?

Actually I want to dinamically assign bootfile-name based on clients MAC. I have tried this config: option bootfile-name concat( binary-to-ascii(16, 8, "", substring (hardware, 1, 6)), ".cfg"); But ...
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1answer
2k views

How to trigger DHCP request and inspect the reply from DHCP server

Is it possible to trigger a DHCP request from my DHCP server and then sniff and inspect the whole DHCP reply from the server to see what options/parameters it sends to the clients?
4
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0answers
224 views

Assigning option based on class membership inside the subnet section

We are looking for a way to do something along these lines in the dhcpd.conf file: subnet ... { #couple of options for the subnet here pool { allow members of "class-name1"; ...
1
vote
1answer
845 views

Libvirt providing bootp options without being configured to do so

I have a virtual network configured in libvirt and configured to provide DHCP (via dnsmasq) but not configured to provide bootp information (see below), but when I boot an iPXE ISO and look at the ...
1
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0answers
786 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 dhcp6....
2
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1answer
1k views

Why use FQDN as DNS-server option in DHCP?

I've seen multiple default configurations of DHCP-servers with a FQDN set as the DNS-server option. Doesn't this imply a catch-22, or the need for that DNS-server to be in the hosts file of every ...
3
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1answer
538 views

Cannot assign IP address according to an option parameter

I have this DHCP conf file: authoritative; option domain-name "XXX.XXX.XX"; allow bootp; ddns-update-style ad-hoc; class "karpuz-kabugu" { match if (substring (option user-class, 0, 6) = "karpuz")...
2
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1answer
3k views

Mac OS X Server Configure DHCP Options 66 and 67

I need to configure Mountain Lion (10.8.2) OS X Server BOOTP to provide DHCP options 66 and 67 to provide PXE booting for PCs on my network. I have tried following the bootpd MAN pages, but they are ...
2
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0answers
702 views

setup static route via dhcp

I try to push static routes over dhcp in a redhat enviroment. I have already activatet the option rfc3442-classless-static-routes. The dhcp client is also configured to request this optien as ...
2
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1answer
2k views

How to pass a vendor-specific options to a DHCP server using dhclient?

I need to send vendor-options to DHCP server using dhclient (ISC). As I understand I need to describe that options in the dhclient.conf. Do I need make new "space" for options? Or I can do "send"? ...
3
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2answers
2k views

How to save DHCP option 43 on Windows 2008 server?

I need to retrieve the DHCP option 43 from my DHCP server (Linux ISC DHCP server) on a Windows 2008 server (or any other Windows version, as long as the code 43 is specified in the Parameter request ...
1
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1answer
9k views

ISC-DHCP-SERVER - Can different reservations get different options (router, DNS, etc)?

Suppose there's just one Ubuntu / ISC-DHCP (v3) server on the network. I've successfully been able to provide "DHCP reservations" meaning MAC foo gets ip 1.2.3.4, whereas everyone else just gets an ...
3
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1answer
221 views

DHCP IPV6 Environment

May I know what are the changes needed in the DHCP message formats if I want to convert into ipv6 environment? Now I am using ipv4 dhcp client and ipv4 dhcp server. But I want to implement this using ...
5
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3answers
40k views

Linux DHCP server option 43 vendor-encapsulated-options, how to format/encode?

I admin the network for a small business which has an IPCop firewall box providing DHCP services to the network (and various other services). The DHCP server in IPCop appears to be dhcpd and IPCop ...
4
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2answers
15k views

Two DHCP server in the same subnet

So I change jobs recently and in this new workplace I've found that we've actually got two DHCP servers. In the very same subnet, and they both have the same scope. I did not set up this but I see ...
0
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2answers
685 views

Which DHCP clients use which options?

I would like to use my DHCP server to give information about some local services like ntp, using DHCP options as explained in the dhcp-options(5) manpage. Does anyone here know, or is there a good ...
2
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2answers
3k views

Is the native DHCP client for MacOS X able to send “Vendor class identifier” (opTag 60) in a DHCP request?

Is it possible for MacOS X (current version or in any previous one) to easily force DHCP client to send to DHCP server, at the beggining of the conversation - in DHCPDISCOVER packet - option "Vendor ...