Spoiller: go to the bottom of the page. When you add an IPV6 address to your control panel, like Plesk, you must still use SSH and use CLI to configure the IPv6 address on the CentOS/Umbuntu server’s network interface at the OS level. This is not necessary when adding IPV6 addresses.
The problem can mask itself in many ways, especially after reboot. In one case, you are experiencing two main issues in your Plesk control panel on Linux:
The “Services Management” and “Web Configuration Troubleshooter” pages hang and do not load, while other links work.
The “Diagnose and Repair” tool reports many missing .conf files for various domains, and repair attempts do not resolve these errors.
Analysis and Likely Causes
1. Hanging Pages (“Services Management” and “Web Configuration Troubleshooter”)
This behavior often indicates an underlying problem with the web server configuration or Plesk services. If configuration files for domains are missing, Plesk may be unable to generate or read the necessary data, causing certain tools to hang when they attempt to access or rebuild these configurations[1][2].
2. Repeated “File not found: [domain].conf” Errors
These errors mean that Plesk expects configuration files for these domains (typically in /etc/httpd/conf/plesk.conf.d/vhosts/ for Apache or /etc/nginx/plesk.conf.d/vhosts/ for Nginx), but they are missing. This can occur if:
The domains were deleted improperly.
There was a failed migration or backup restore.
The filesystem was altered outside of Plesk.
If the domains still exist in Plesk, the system will repeatedly try to generate these missing configs and fail, leading to persistent errors and potentially causing tools that depend on these files to hang.
Recommended Steps to Resolve
1. Run the Plesk Repair Utility via SSH
Use the command line to attempt a deeper repair, which may succeed where the GUI fails:
plesk repair all -v
or, to focus on web and FTP services:
plesk repair web -v
plesk repair ftp -v
This will provide detailed output and may resolve or clarify the web server configuration issues[3][4].
2. Use the Webserver Configuration Troubleshooter (CLI Alternative)
If the GUI for the Webserver Configuration Troubleshooter is inaccessible, install and run it from the command line:
plesk installer –select-release-current –install-component config-troubleshooter
plesk ext config-troubleshooter –check
This will analyze web server configuration issues and may offer specific error messages or solutions[1][2].
3. Investigate and Clean Up Domain Configurations
If the affected domains are no longer in use, remove them from Plesk via the CLI or GUI (if accessible).
If they should exist, use the repair tools above to attempt to regenerate their configs.
Check for orphaned database entries or subscriptions in Plesk that reference these domains and clean them up if necessary.
4. Check Logs for More Details
Review Plesk and web server logs for errors that may explain why the config files are missing or why the repair tools are failing:
/var/log/plesk/panel.log
/var/log/httpd/error_log (Apache)
/var/log/nginx/error.log (Nginx)
Look for lines containing “fail”, “No such file”, or “error”[2].
5. Restart Plesk and Web Services
After repairs, restart Plesk and the web servers:
service psa restart
service httpd restart # For Apache
service nginx restart # For Nginx
This ensures all changes are applied and services are running[5].
Summary Table
Symptom | Likely Cause | Solution Steps |
Hanging Plesk tools | Broken/missing domain configs | Repair via CLI, clean up domains, restart |
“File not found: [domain].conf” | Orphaned/missing config files | Repair web/ftp, check logs, clean up |
If Problems Persist
If the CLI repair tools and troubleshooting steps do not resolve the issue, you may need to manually remove orphaned domain entries from the Plesk database or filesystem.
For persistent or complex issues, consider contacting Plesk support or restoring from a recent backup.
References:
⁂
after reboot i was finally able to at least run the plesk Web server Configuration Checker, and I cannot start nginx due to these dam ipv6 addresses that plesk has huge problems with. here is the checker error: Checking nginx configuration
nginx: [emerg] bind() to [2607:f1c0:86f:7659:2:2:2:2]:443 failed
(99: Cannot assign requested address)
nginx: configuration file /etc/nginx/nginx.conf test failed
………………………………………………………… [ERROR]
Your nginx startup failure is caused by Plesk trying to bind nginx to an IPv6 address ([2607:f1c0:86f:7659:2:2:2:2]:443) that does not exist or is not configured on your server’s network interfaces. This is a common Plesk issue, especially after reboots or network changes, and results in the error:
nginx: [emerg] bind() to [2607:f1c0:86f:7659:2:2:2:2]:443 failed (99: Cannot assign requested address)
nginx: configuration file /etc/nginx/nginx.conf test failed
Why This Happens
Plesk stores IP addresses in its database and generates nginx configs for all listed addresses, even if the OS does not have those IPs configured.
If the IPv6 address is missing from the OS network configuration, nginx cannot bind to it and fails to start[6][7][8].
Solutions
1. Allow Nginx to Bind to Non-Local IPv6 Addresses (Quick Fix)
This allows nginx to start even if the IPv6 address is not present (recommended by Plesk):
SSH into your server.
Add this line to the bottom of /etc/sysctl.conf:
net.ipv6.ip_nonlocal_bind = 1
Apply the change:
sysctl -p
Restart nginx:
systemctl restart nginx
This workaround lets nginx bind to addresses not yet present, resolving the immediate startup issue[6][7].
2. Clean Up Broken or Stale IPv6 Addresses in Plesk (Permanent Fix)
In Plesk, go to Tools & Settings > IP Addresses.
Look for any IPv6 addresses marked with an exclamation point or broken state.
Click repair or remove any IP addresses that do not exist on your server[8].
If none are marked, click re-read to refresh the list.
After cleanup, reconfigure web server configs:
/usr/local/psa/admin/sbin/httpdmng –reconfigure-all
Restart nginx:
systemctl restart nginx
3. Ensure OS Network Configuration Matches Plesk
Verify with ip -6 addr or ifconfig that the IPv6 address is actually present.
If not, either add the IPv6 address to your network interface or remove it from Plesk as above[9][10][8].
Summary Table
Solution | Effect |
Allow nonlocal bind | Immediate workaround; lets nginx start even if IP is absent |
Clean up Plesk IP addresses | Permanent fix; prevents future config errors |
Sync OS and Plesk IPs | Ensures configs match actual server state |
Recommendation:
Apply the net.ipv6.ip_nonlocal_bind = 1 workaround for immediate relief, but also clean up your Plesk IP addresses for long-term stability[6][7][8].
⁂
in plesk, i went to tools and settings > ip addresses. only that one ipv6 address shows and under it I now see an error has been added that was not there before, with a repair link. i wonder why it says it is not configured proeprly. It shows like this in plesk: 2607:f1c0:86f:7659:2:2:2:2 / 128
This IP address is not configured properly. Repair
The error “This IP address is not configured properly” in Plesk means that Plesk sees the IPv6 address (2607:f1c0:86f:7659:2:2:2:2/128) in its database, but this address is not actually configured on any of your server’s network interfaces[11][12][13]. This mismatch often occurs after network changes, OS updates, or if the server was provisioned with a dynamic IPv6 address that has since changed or disappeared.
Why This Happens
Plesk expects all IPs listed in Tools & Settings > IP Addresses to be present on the server’s network interfaces.
If the OS does not have this IPv6 address configured, Plesk marks it as “not configured properly” and offers a “Repair” link[11][12][13].
Clicking “Repair” rarely works unless the underlying network configuration is fixed[13].
How to Fix
1. Confirm the IPv6 Address on Your Server
SSH into your server and run:
ip -6 addr
or
ifconfig
If you do not see 2607:f1c0:86f:7659:2:2:2:2 listed, that’s the problem.
2. Remove the Broken IPv6 Address from Plesk
In Plesk, go to Tools & Settings > IP Addresses.
Remove the problematic IPv6 address.
If you need IPv6, add the correct static IPv6 address that is actually configured on your server.
3. (If Needed) Add the IPv6 Address to Your Network Interface
If you want to keep using this IPv6 address, add it to your server’s network configuration. For example, on Ubuntu with Netplan:
Edit your Netplan YAML file (e.g., /etc/netplan/01-netcfg.yaml) and add the IPv6 address to the correct interface[11][12].
Apply changes with:
netplan apply
4. Reread IP Addresses in Plesk
After fixing the network config, in Plesk go to Tools & Settings > IP Addresses and click Reread IP to refresh the list[11][12].
Additional Notes
If your server was assigned a dynamic IPv6 address, Plesk may not handle it well. For production, always use a static IPv6 address[12][14].
If you’re on Plesk Obsidian 18.0.27 or later, you can enable limited support for dynamic IPv6 in the panel.ini (not recommended for production)[12][14].
Summary Table
Problem | Cause | Solution |
IP not configured error | IP not present on server interface | Remove from Plesk or add to server config |
“Repair” doesn’t work | Underlying OS config not matching Plesk | Fix network config, then reread in Plesk |
In short:
Plesk is warning you because the IPv6 address is not actually set up on your server’s network interface. Either remove it from Plesk or configure it on your server to resolve the error[11][12][13].
⁂
OK, I removed the address before trying to repair it, I tried this before rebooting and it failed to delete ipv6 address, but it is gone now. should i try to restart nginx now?
Yes, now that you have removed the problematic IPv6 address from Plesk, you should try to restart nginx. Removing the address from Plesk should update the configuration files so that nginx no longer tries to bind to a non-existent address, which was the cause of the previous error[15][16][17].
Recommended steps:
Reconfigure your web server configs to ensure Plesk generates new, correct configuration files:
/usr/local/psa/admin/sbin/httpdmng –reconfigure-all
Then restart nginx:
systemctl restart nginx
or
service nginx restart
If nginx starts successfully, the issue is resolved. If you still encounter errors, check /var/log/nginx/error.log for any remaining references to missing or misconfigured IP addresses[18][15][16]. If errors persist, a server reboot or rereading IPs in Plesk (Tools & Settings > IP Addresses > Reread IPs) may help finalize the cleanup[15].
⁂
well, what I did was simply REREAD the ip’s like you said, and my domains now resolved. Then I checked the congig troubleshooter, and there are no longer any issues. Also the diagnose and repair no longer shows all those missing configuration files. very strange dont you think?
Your experience is actually a known behavior with Plesk’s IP address management. When you removed the problematic IPv6 address and then used the “Reread IP” function, Plesk refreshed its internal list of network interfaces and IPs, which prompted it to update all related configuration files for web and FTP services[19][20][21][22]. This action removed references to the missing or misconfigured IP, allowing Plesk to regenerate clean, correct configs for all domains.
That’s why:
Your domains started resolving again.
The configuration troubleshooter found no more issues.
The “Diagnose and Repair” tool no longer showed missing configuration files.
While it can seem strange, this is exactly how Plesk is designed to recover from IP configuration mismatches: the “Reread IP” function acts as a reset, syncing Plesk’s database with the actual state of your server’s network interfaces and removing stale or broken references[19][21][22]. This is a common fix for “IP address not configured properly” and similar errors, especially after network changes or removing problematic IPs[19][20][21].
So, while it might feel odd that such a simple step resolved a cascade of issues, it is the intended and documented recovery process in Plesk[19][20][21][22].
⁂
ok thanks. now lets talk about why these ipv6 addresses are so problematic all the time and everyone is bitching about it 🙂 So what I did was add a new ipv6 address at the ionos server control panel. Then I went to plesk and added the ipv6 address to the TOOLS AND SETTINGS> IP ADDRESS section. Is not that enough? Did I have to check and use the ipconfig and then netplan apply command you mentioned? I assume plesk would handle it. or did I enter the ip address incorrectly when I added it as 2607:f1c0:86f:7659:2:2:2:2 128 – I believe the /128 was correct which I had to add to the end of the assigned ipv6 address
Adding an IPv6 address in your host’s control panel (like IONOS) and then in Plesk’s Tools & Settings > IP Addresses is only part of the process. For the address to work correctly, it must also be configured on your server’s operating system network interface. Plesk does not automatically configure the OS-level network settings for new IPs added in the panel—it expects the IP to already be present and properly configured on the server[23][24][25][26].
Why IPv6 Causes So Many Problems in Plesk
- Manual Coordination Required: You must ensure the IPv6 address is set up both in your hosting provider’s control panel and on your server’s network interfaces. Plesk only manages its own database and web server configs; it does not configure the Linux network stack for you[23][24][25].
- OS-Level Configuration Needed: If you add an IPv6 address in Plesk but not to your server’s network config (e.g., via Netplan, /etc/network/interfaces, or ip addr add), Plesk will report the IP as “not configured properly,” and web services may fail to bind to it[23][25].
- Common Mistakes: Many admins assume adding the IP in Plesk is enough, but unless the OS recognizes the address, Plesk’s services (like nginx and Apache) can’t use it, leading to errors like you experienced.
- Syntax: The correct format for adding an IPv6 address is 2607:f1c0:86f:7659:2:2:2:2/128 (with a slash, not a space, before the prefix length)[23][25]. Entering it as 2607:f1c0:86f:7659:2:2:2:2 128 (with a space) may not be interpreted correctly by some tools or configs.
What You Should Do
- Configure the IPv6 Address on the Server OS:
ip -6 addr add 2607:f1c0:86f:7659:2:2:2:2/128 dev eth0
-
For permanent configuration, update your Netplan YAML or /etc/network/interfaces file and apply with netplan apply or restart networking.
- Check with ip addr:
Run ip addr to confirm the IPv6 address appears under your network interface and has scope global[23].
- Add the IPv6 Address in Plesk:
- Reread IPs in Plesk:
If you make changes, use the “Reread IPs” button in Plesk to sync its database with the OS state[26].
In Summary
Adding the IPv6 address in your host panel and in Plesk is not enough—you must also configure it on your server’s OS network interface[23][24][25][26].
Use the correct syntax: 2607:f1c0:86f:7659:2:2:2:2/128.
Always verify the address is active on your server with ip addr.
This manual, multi-step process is why so many admins struggle with IPv6 in Plesk and why it’s a frequent source of frustration in the community[27].
If you follow these steps, Plesk should recognize and use your IPv6 address without further issues.
⁂
actually I did have it entered as 2607:f1c0:86f:7659:2:2:2:2/128, somehow that space was errant. I have never used a network configuration tool, so are you positive we must do this command line work effort? And please tell me the exact steps to Configure the IPv6 Address on the Server OS using whichever tool is easiest for centos linus
You are correct that entering the IPv6 address as 2607:f1c0:86f:7659:2:2:2:2/128 is the right format—no space, just the slash before the prefix length.
However, yes, you absolutely must configure the IPv6 address on the CentOS server’s network interface at the OS level. Plesk does not handle this part; it only manages web server configuration and expects the OS to already have the address set up[28][29][30]. If you skip the OS configuration, the address will show as “not configured properly” in Plesk, and web services may fail to bind to it.
Step-by-Step: Configure IPv6 Address on CentOS (the easiest way)
Here’s how to do it using the standard CentOS network scripts (works for CentOS 7 and similar):
1. Back Up Existing Network Config Files (Recommended)
cp /etc/sysconfig/network /etc/sysconfig/network.bak
cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0.bak
(Replace eth0 with your actual network interface name if different. Use ip addr to check.)
2. Edit the Network Configuration
Open the main network config file:
nano /etc/sysconfig/network
Add or ensure these lines are present:
NETWORKING=yes
NETWORKING_IPV6=yes
IPV6_AUTOCONF=no
HOSTNAME=your.server.hostname
(Replace your.server.hostname with your actual hostname.)
Open your network interface config (replace eth0 if needed):
nano /etc/sysconfig/network-scripts/ifcfg-eth0
Add or update these lines:
IPV6INIT=yes
IPV6ADDR=2607:f1c0:86f:7659:2:2:2:2/128
# Optional: If your host provides a gateway, add it:
# IPV6_DEFAULTGW=2607:f1c0:86f:7659::1
Make sure ONBOOT=yes is set so the interface comes up after reboot.
3. Restart Networking
systemctl restart network
or, on older systems:
service network restart
4. Verify the IPv6 Address
ip addr show eth0
You should see your IPv6 address listed under your interface[28].
5. Finalize in Plesk
Go to Tools & Settings > IP Addresses.
Click Reread IPs to make Plesk detect the new address.
Assign the address to your subscriptions as needed.
Why This Is Necessary
The OS must have the IPv6 address configured so that services like nginx, Apache, and Plesk itself can bind to it[28][29][30].
Plesk does not set up OS networking for you—it only manages its own configs and expects the OS to provide the IP.
Summary Table
Step | Command/Action |
Backup files | cp /etc/sysconfig/network /etc/sysconfig/network.bak |
Edit config | nano /etc/sysconfig/network-scripts/ifcfg-eth0 |
Restart net | systemctl restart network |
Verify | ip addr show eth0 |
Reread in Plesk | Use “Reread IPs” in Plesk panel |
If you follow these steps, your IPv6 address will be properly configured and Plesk will recognize it as valid.
⁂
Good hell, that is a lot of work and room for error! Hey I am just a hack but I had 15 of these dedicated servers over the years with no problem until this ipv6 stuff started giving me grief.
You’re absolutely right: compared to IPv4, IPv6 setup in Plesk (and on Linux in general) is more involved and error-prone for most admins, especially since Plesk doesn’t automate the OS-level network configuration. This is a common frustration, and you’re not alone—many experienced server admins have run into these headaches as IPv6 adoption has increased[31][32].
Here’s why it’s more complex, and what you actually need to do on CentOS:
Why IPv6 Setup Is More Complex
- Plesk Only Manages Its Own Database: When you add an IPv6 address in Plesk, it expects that address to already be configured and active on your server’s network interface. If it’s not, Plesk can’t use it and will show errors[33][32][34].
- OS Network Configuration Is Separate: You must manually add the IPv6 address to your CentOS network interface configuration files. Plesk will not do this for you[33][34].
- Potential for Typos or Misconfiguration: If the address is entered incorrectly or on the wrong interface, or if there’s a typo in the config files, it won’t work—leading to “not configured properly” errors in Plesk and failed web services.
Do You Really Need to Use the Command Line?
Yes, for CentOS you must configure the IPv6 address at the OS level.
There is no GUI in Plesk or CentOS that will automatically do this for you. The command line (editing config files or using nmcli) is required[33][32][34].
Step-by-Step: Easiest Way to Add IPv6 on CentOS
Option 1: Edit Network Script (Traditional CentOS Method)
- Find your network interface name:
ip addr
(Look for something like eth0, ens18, etc.)
- Edit the interface config file:
nano /etc/sysconfig/network-scripts/ifcfg-eth0
(Replace eth0 with your actual interface name.)
- Add these lines (or update if already present):
IPV6INIT=yes
IPV6ADDR=2607:f1c0:86f:7659:2:2:2:2/128
# Optional: If your host provides a gateway, add:
# IPV6_DEFAULTGW=2607:f1c0:86f:7659::1
ONBOOT=yes
(Do not add a space before /128.)
- Restart networking:
systemctl restart network
or
service network restart
- Verify:
ip addr
Make sure you see your IPv6 address listed under the correct interface.
Option 2: Use NetworkManager’s nmcli (if your CentOS uses NetworkManager)
- Add the IPv6 address:
nmcli connection modify eth0 +ipv6.addresses 2607:f1c0:86f:7659:2:2:2:2/128
nmcli connection up eth0
(Replace eth0 as needed.)
- Verify with ip addr as above.
Final Step: Add in Plesk
Now, go to Tools & Settings > IP Addresses in Plesk and add the same IPv6 address.
Click Reread IPs if needed.
Assign the address to your subscriptions as required.
Why This Is Necessary
Plesk and your OS are separate layers. The OS must have the IPv6 address active so Plesk can use it—otherwise, you get errors and broken services[33][32][34].
Community Perspective
You’re not alone in finding this frustrating. Many admins have voiced similar complaints about the manual steps and lack of integration[31][32]. The process is error-prone, but following these steps ensures stability.
In summary:
Yes, you must configure the IPv6 address at the OS level on CentOS, using the command line, before Plesk can use it. This is the root cause of most IPv6 headaches with Plesk on Linux[33][32][34].
References:[31]
Plesk forum discussion on IPv6 config[33]
Plesk support: How to enable IPv6 addresses[32] DN.org
: Setting up IPv6 in Plesk[34] Plesk KB: How to enable IPv6 addresses
⁂
One of my servers is umbuntu, is the process the same, or please give me step by step.
Here are the step-by-step instructions for configuring a static IPv6 address on an Ubuntu server (18.04, 20.04, 22.04, and later), using the Netplan utility, which is the default on modern Ubuntu releases:
Step-by-Step: Configure a Static IPv6 Address on Ubuntu (with Netplan)
1. Check Your Network Interface Name
First, determine the name of your network interface (e.g., ens3, enp0s3, eth0):
ip a
Look for the interface connected to your network.
2. Edit the Netplan Configuration File
Netplan config files are typically found in /etc/netplan/. The file might be named 01-netcfg.yaml, 50-cloud-init.yaml, or similar.
Open the file in a text editor (replace the filename as needed):
sudo nano /etc/netplan/01-netcfg.yaml
3. Add Your IPv6 Configuration
Below is a sample configuration. Replace the interface name, IPv6 address, prefix, gateway, and DNS as needed:
network:
version: 2
renderer: networkd
ethernets:
ens3: # <– Replace with your interface name
dhcp4: no
dhcp6: no
addresses:
– 2607:f1c0:86f:7659:2:2:2:2/128 # <– Your IPv6 address and prefix
gateway6: 2607:f1c0:86f:7659::1 # <– Your IPv6 gateway (ask your provider if unsure)
nameservers:
addresses:
– 2606:4700:4700::1111 # Cloudflare IPv6 DNS
– 2001:4860:4860::8888 # Google IPv6 DNS
Indentation is crucial in YAML files.
4. Apply the Configuration
Save and exit the editor, then apply the changes:
sudo netplan apply
This will activate your new network settings immediately[35][36][37].
5. Verify Your IPv6 Address
Check that your IPv6 address is active:
ip -6 addr
You should see your IPv6 address listed under your network interface.
6. Test IPv6 Connectivity
Try pinging an IPv6 address to confirm connectivity:
ping6 google.com
If you get replies, your IPv6 is working.
Optional: Enable IPv6 in UFW Firewall
If you use Ubuntu’s UFW firewall, make sure IPv6 is enabled by editing /etc/default/ufw and setting:
IPV6=yes
Then reload UFW:
sudo ufw reload
Summary Table
Step | Command/Action |
Check interface | ip a |
Edit Netplan file | sudo nano /etc/netplan/01-netcfg.yaml |
Apply changes | sudo netplan apply |
Verify address | ip -6 addr |
Test connectivity | ping6 google.com |
Key Point:
You must configure the IPv6 address on the OS (with Netplan on Ubuntu) before adding it in Plesk—just like on CentOS[35][36][37]. Plesk will not do this for you.
If you need to use the older /etc/network/interfaces method (for Ubuntu 16.04 or earlier), let me know and I’ll provide those steps.
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