Questions tagged [isc-dhcp]
ISC DHCP is open source software that implements the Dynamic Host Configuration Protocols for connection to a local network. It is a reference implementation of those protocols, but it is also production-grade software, suitable for use in high-volume and high-reliability applications. DHCP is available for free download under the terms of the ISC License, a BSD style license.
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Linux Bind9 DNS server, configuration throwing errors
I am having problem with DNS configuration in Linux. I am using isc-dhcp-server as DHCP server and bind9 as DNS server, but I it returning me errors.
This is my Setup
Internet <--enp0s3 interface--&...
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2
answers
217
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DHCP starting before network is ready
I am having a problem with my DHCP server. When it restarts the isc-dhcp-server does not get ready because the network (it uses NetworkManager) is not ready.
I put a sleep command in the isc-dhcp-...
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votes
1
answer
118
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How do I deploy correctly my DHCP Servers with DHCP Option 82?
My Goal is to achieve a seperate DHCP Pool on my switches, how am I able to achieve it on a flat network hosted for a LAN-Party. Which means seperate VLANs should be avoided
We're talking about ...
1
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1
answer
196
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Stuck with DHCP option 43/60 with ISC
if´ve already checked the existing threads for option 43, but I don´t get it for my case.
I want to implement a thin-client auto-registration in our productive thin-client subnet - and I´m not DHCPD ...
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1
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125
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Why am I not able to resolve names on subnet behind a lab network?
I have gotten the task of setting up a network where there is an existing gateway for my "public ip" 10.200.3.2/28 already. I am to setup a gw/dhcp which uses the existing gateway the given ...
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0
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307
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Different gateway for a single host in DHCP server
I am using ISC DHCP Server and I want to assign a different default gateway for one of the devices using that DHCP.
I have the network 192.168.0.0/24, and two redundant ISC DHCP servers assign IP ...
- 51
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1
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94
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how to parse DHCP vendor-specific-info
Hello I would like to allocate IP based on the serial number as the mac address is not available without me connecting physical cable and login.
Tcpdump PCAP DHCP packet:
TIME: 2023-10-27 09:58:33....
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0
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1k
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ISC DHCP server web interface
I want to ask what web interface could be used for isc dhcp server on Ubuntu 22.04 server. I want to create dhcp server on ubuntu, I installed and configured isc dhcp but now i want to manage it from ...
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1
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639
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isc-dhcp-server "No subnet declaration for enP4p65s0"
TL;DR: I'm aiming at configuring my own Ubuntu 22.04LTS-based router for my home network, using isc-dhcp-server, nftables & NetworkManager. I'm experiencing weird DHCP behaviors.
I'm using a Nano ...
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1
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1
answer
426
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DHCP server does not provide correct filename for PXE
I'm trying to configure PXE server for both Legacy/UEFI support. So I need to provide different bootloaders based on architecture of machine.
Here's part of dhcpd.conf:
option architecture-type code ...
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1
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654
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Centos 7 dhcp server not responding to UEFI PXE DISCOVER
I'm trying to set up a Centos 7 server as a dhcp server for PXE (UEFI). I'be tried several changes to the dhcpd.conf file, but nothing seems to make a difference.
dhcpd.conf:
allow booting;
allow ...
1
vote
2
answers
2k
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No subnet declaration for WAN
I have 2 netcards enp0s3 for WAN and enp0s8 for LAN.
WAN has dynamic IP address (received from ISP).
LAN has class C static IP address for my local network
I have isc-dhcp-server with this config:
...
- 398
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1
answer
140
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Migration strategy to migrate a DHCP scope from old DHCP server to new DHCP server as smooth as possible
My current homeLab and entire home is currently running on a single subnet 192.168.0.0/24 with my ISP provided router running a DHCP scope handing out addresses in the 192.168.0.20-192.168.0.254 range,...
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1
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323
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Setting up LAN gateway for school club network - "No subnet declaration for enp3s0"
I am a computing teacher, I am trying to setup a "sandbox" network with internet access for an after school computing club.
I have an old PC (Debian 11 installation) with 2 ethernet ...
0
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0
answers
91
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Configure a DHCP server with isc that gives the clients IPs depending on the OS
The problem is that I cannot put a static IP or filter by mac because some clients have dual boot and use both Windows and Ubuntu, I need to be able to somehow distinguish between both OS and both ...
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1
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809
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DHCP logs showing (no free leases)
I have setup new isc-dhcp-server in ubuntu 20.04. all client getting connect but showing there logs (no free leases)
client connected only 25 machine.
sudo tail -f /var/log/syslog
Sep 9 09:43:57 ggn-...
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1
answer
1k
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Decode UID from dhcpd.leases
I have am testing a device on my network which has this lease assigned:
lease 192.168.110.85 {
starts 3 2022/07/20 16:12:37;
ends 3 2022/07/20 16:22:37;
cltt 3 2022/07/20 16:12:37;
binding ...
- 297
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1
answer
1k
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ISC DHCP Server - Matching client identifier won't work for single device
I hope someone can help me with this problem.
What am I trying to do
I want to provide information to a Cisco ASR1k depending on its serial number.
Reason for this is I don't have any MAC address of ...
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1
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4k
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How to supply hostname using isc-dhcp-server to hosts without fixed-address
I have a DHCP+DNS setup on my network using bind9 and isc-dhcp-server. It works fine for all clients that have a "proper" hostname configured without any special setup in dhcpd.conf in the ...
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RFC 3074 DHCP Load Balancing STID vs RFC 2131 DHCP xid
Section 2.2 of RFC 3074 defines a Service Transaction ID (STID) as:
An attribute of the individual client requests used for load-balancing.
However, section 2 of RFC 2131 defines the xid field of a ...
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1
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1k
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ISC DHCP for relay agents
I would like to configure DHCP server for my networks, but in the same time, i don't want to setup dhcp server on the network where the server itself is.
DHCPD insist to configure subnet declaration ...
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1
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450
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isc-dhcp-server ip-range speicifc domain-name-server
I'm trying to get an isc-dhcp-server configuration to use different DNS-Servers based on the ip-address assigned.
Basically, I want some of my client marked as not-trusted, which then may not access ...
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1
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495
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What is the proper way to back up ISC DHCPd lease files?
According to this answer, DHCPd lease files are cleared every hour. The goal is to back up the leases file continuously, so there is never a lease lost. This is made difficult since it is unclear ...
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2
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2k
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Simple stateful DHCPv6 using ISC DHCP and RADVD. Doesnt work?
I'm trying to set a simple ipv6 network using ISC DHCPv6 on a linux machine.
Here is my dhcpd6.conf:
subnet6 beef:fade::/112 {
max-lease-time 3600;
range6 beef:fade::100 beef:fade::fffe;
}
The ...
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0
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558
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isc-dhcp-server not replying to relayed requests
DHCP request is being relayed from a server in a different subnet to the ISC-DHCP box.
ISC-DHCP is not responding
dhcpd.conf is like this:
subnet 10.0.1.10 netmask 255.255.255.254 {}
host test {
...
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1
answer
94
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Dynamic Google hosted DNS zone update by DHCP
I have dns zone running in Google Cloud.
I would like to integrate my ISC-DHCP with that zone by enabling automatic host registration into the zone.
I'm looking for some analogy to enable in Google ...
google-cloud-platform
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0
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646
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ISC-DHCP and BIND 9 DNS: DDNS update fails for /27 subnet
I have a problem with DDNS update with ISC-DHCP server.
My /etc/dhcp/dhcpd.conf subnet section that doesn't work is:
subnet 193.198.186.192 netmask 255.255.255.224 {
range 193.198.186.200 193.198....
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554
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ISC DHCP/DDNS setup: Static entries for non-dhcp clients
I have set up a local network with ISC BIND9 and DHCP service. New leases trigger the DHCP to add an A and PTR record which works perfectly.
I also added lots of static host entries in the dhcpd.conf. ...
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1
answer
863
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DHCP server failover with dynamic bootp range declaration
I am trying to configure a failover for a ISC dhcp server running on Linux that has dynamic-bootp range declaration.
The configuration file looks like this (I am trying it locally first, therefore ...
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0
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196
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ISC Dhcpv6 pool
I recently set up a dhcpv6 server in my network. The problem is: I set the range of it to
#VLAN120
subnet6 2001:470:2249:120::/64 {
range6 2001:470:2249:120::20 2001:470:2249:120::250;
...
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1
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442
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isc dhcp multiple option 240 in same subnet
I'm fairly new to isc dhcp.
I'm working at an ISP and need to provide our STB's with an option 240, and it has worked fine for years, the problem now is that we are getting a newer model, that needs a ...
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1
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2k
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isc-dhcp-server assigns same IP address for different hosts
I have an isc-dhcp-server running in a Docker container, which I configured with one subnet of 100 available IP @.
When starting my laptops (they are all running Linux OS), when they are requesting IP@...
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1
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536
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DHCP Pools on Ubuntu DHCP server not working properly
Mac addresses ending with "55:a3" and "56:2a" are also ending up in last pool
123 match if binary-to-ascii(16,8,":",substring(hardware, 5, 6)) = "55:a3"; ...
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2
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dhcpd server invalid MAC detection
On my DHCP configuration, I have on commit hook to save device information. My problem is some of the MAC addresses becomes invalid:
8:7c:39:cf:b6:3f - this should start with zero
8:d0:b7:52:f9:68 - ...
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0
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682
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isc-dhcp-server can't get DHCPDISCOVER packet from some clients whose MAC address not in the subnet
isc-dhcp-server running normal, it can offer IP address to most clients in all subnet which are defined in the dhcpd.conf file, but it can't receive some DHCPDISCOVER packet from several clients which ...
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0
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What is the exact meaning of "On Commit" in ISC DHCP server configuration?
I know there are three kinds of events we can use for scripting in ISC dhcpd -- commit, expire and lease. My problem is, I am having a little problem in understanding the "commit" event. I ...
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1
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5k
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how to load grub with menu in ipxe setup
I am trying to setup an ipxe environment on a vmware.
I would like to configure the setup with UEFI.
I have setup a ubuntu-server and configured it as pxe-server.
via downloading ipxe, isc-dhcpd, tftp-...
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Define multiple filename options in DHCP config based on different range
Intro
I am trying to use a centos box for DHCP and TFTP function, for iPXE boot.
I have one subnet configured for DHCP, but it has multiple ranges and each range has a different iPXE boot URL.
Problem
...
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1
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295
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Cannot ping anything on intranet or internet when connected to second subnet in isc-dhcp-server
On my local network, I've got Ubuntu Server running isc-dhcp-server and named. I have a lot of devices that I've assigned static addresses to, and up until now have assigned a small range of IP ...
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1
answer
3k
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isc-dhcp-server does not push domain-name to client
I have installed the DHCP server (isc-dhcp-server) on my Ubuntu 20.04. The client computer (also a Ubuntu 20.04 Desktop machine) gets assigned IP address, but id doesn't get the assigned domain-name (...
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1
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1k
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Server DHCPv6 with Linux Alpine
I want create a server dhcp6 with alpine
I'm using Kea-dhcp6. The my file config this is:
{
# DHCPv6 configuration starts on the next line
"Dhcp6": {
# First we set up global values
&...
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1
answer
234
views
Windows AD not updating Linux DDNS in hybrid integration
I am setting up a Windows AD server, with a Linux DDNS setup. The Linux DDNS runs perfectly fine as expected. However, when I try to add the AD role to the Windows Enterprise 2019 server, the role ...
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0
answers
412
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How to get custom option on client from ISC DHCP server
Over ISC-DHCP server I wanted to define a custom DHCP Option, for which I am using below config
option imagefile code 224 = ip-address;
subnet 192.168.29.0 netmask 255.255.255.0 {
range 192.168.29.1 ...
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1
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6k
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netplan - Network with DHCP configured, but no internet
I am trying to configure my Ubuntu Server 20.04 LTS to use DHCP in its network configuration.
Many tutorials on the internet recommend that I create the following file with the following settings...
...
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1
answer
8k
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Unable to add forward map SERVFAIL/REFUSED DDNS
I am using bind9 on a primary dns server with two secondary dns servers in a master/slave relationship. I am attempting to implement DDNS but seem to be running into a problem when it comes to adding ...
- 13
0
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0
answers
1k
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Block the DHCP server from broadcasting into the second ethernet interface
I have setup my DHCP server by following the instructions in https://wiki.debian.org/DHCP_Server.
This all works but the issue I am having is the DHCP server is being broadcast in the main company ...
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0
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704
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Can isc-dhcpd be configured to remove DNS records when leases expire?
I've configured my dhcp server so it can successfully add records to a private DNS zone when it issues a lease for a client.
I never see it removing a lease however.
Is it supposed to do so or is ...
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1
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1k
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Why is ISC DHCP server ignoring the fixed-address statement?
I want for the devices which belong to different VLANs to have different routers. For instance:
The device 10.0.10.84 inside a VLAN 10.0.10.0/24 would have its router set to 10.0.10.1, whereas:
The ...
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2
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926
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DHCP Server - Unable to share Internet to clients
note: I will call the server running isc-dhcp-server "DHCP-SERVER", and computer wired to my switch "DHCP-Clients"
Hi,
I am currently setting-up a network, and i am unable to share ...
1
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1
answer
4k
views
how does isc-dhcp-server start on debian 10 with systemd
I'm on a beaglebone black running a debian 10 console image.
A bit of an odd setup that I have, but I need to make it run that way.
The issue:
isc-dhcp-server fails to start at boot, but does start ...
