Windows wired clients not find dhcp server

Hi community Im pretty new using nethserver soo i need your help. Recently i do a fresh nethserver 7.9 installation on a Proxmox VE. The nethserver is used like gateway and i also have running other modules and services like firewall and atuth proxy and PDC. On my green network i have installed a dhcp service and i have some wired Windows 10 client whos are joing to the domain and use nethserver like dhcp but happend me that if i restart or just suspend or maybe unpluged the wired of the client and after plugin it back again this client dont see the nethserever DHCP not matther that the client have a ip reservation or not in the nethserver dhcp place. When that happend i do and ipconfig on the windows clienyt and all is good showme all the parametter with the rigth configuration like i discribed below but when i do a ping to the nethserver the network is unrecheable but the ping to the nethserver AD ip i get response like to the Proxmox VE.

  1. I use a proxmox 6 based on debian buster and i already installed a desktop enviroment xfce on it. But i dont think that this have something to do because i test without the desktop enviroment xfce for the proxmox and i get the same result.
  2. If i do a ping from the nethserver to the client or go to the nethserver diagnostic tab and scan the green network i get response or see the windows client after that the windows client start to get connection again at the moment.

My nethwork configurations is
Proxmox VE
static ip =================
Nethserver …
green interface
FQDN==========> serv1.tcg.lan
static ip=========>192,168.15.254/24
dns ==================> primary secundary
AD & PDC =================>
AD FQDN ==================>ad.tcg.lan
nethserver dhcp server configuration
dns=============== , (i already tray with change the dns order and i still have the same issue)
search doamin====== tcg.lan

red interface
static ip ===========================>
gateway ===========================>
dns ===============================>

ip by dhcp =======================
primary dns=======================
secundary dns=====================
DHCP ===========================
ntp =============================
search domain===================== tcg.lan


Hi Manuel

And Welcome to the NethServer community!

I’m just wondering why anyone uses a .lan domain nowadays!

Just as background Information: .local was suggested by Microsoft before 2000…
(They didn’t really understand DNS then…).
Nowadays, even Microsoft suggests using an unused subdomain of a REAL domain: “ad.domain.tld”…

I would strongly suggest to rethink this, especially now, where you’re still more or less still starting!

Using nonsensical stuff like .lan just makes your life more difficult! You can’t eg use LetsEncrypt for a .lan domain…

As I do not use NethServer as Firewall (Everything else BUT firewall & DHCP), I can’t really help you with your connection issue… I also use Proxmox, so that’s not an issue. (With or without GUI…). You ARE using 2 NICs on your Proxmox?

My 2 cents


Hi Manuel Welcome to the NethServer community!

From the stations with windows, have you made any ping to the AD?

check well what Andy suggests


I and thanks for your quick response. i follow your advise to impruve my system. Yes on the proxmox for the VM where i installed the nethserver i assigned 2 NICs What i can use like firewall & dhcp that have a great compatibility with nethserver to do that wich you suggest me.

Thanks for your quick response. Yes i do and i get response from the ad ip address but not from the Nethserver ip address


Hi Manuel

I use at home and for my clients OPNsense, just as free as NethServer…
And it works well also as a VM in Proxmox and supports VirtIO drivers…

I have 25-30 clients running NethServer for most services (AD, File, Mail, Print, NextCloud, DokuWiki, Zabbix Monitoring). Most of my clients want a seperate “box” as a firewall, so I use PCengines apu4d4 hardware for most. Works well with NethServer together.

One advantage is I still have Internet if i need to do any troubleshooting…

Note: I have installed NethServer also as a firewall on Proxmox (With 2 NICs) and had no issues with it. Often with VMs, especially NethServer the “promicious” mode - needed for the AD container - of NICs (eg on VMWare, Hyper-V or XEN) is an issue, but Proxmox handles this out of the box.
-> I always used a “real” domain, never .local or .lan…

Especially check that you deactivate Proxmox firewall on the NICs!

My 2 cents

Sample Network:

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