Frequently Asked Questions


Q: My EVE is showing: “Eve host license host error (97)”?
A: It can happen if your EVE was very long time offline and after power it on, EVE VM still not received the license validation token. It usually solves automatically in 15 minutes.

To force EVE Pro license validations please do:

1. Make sure EVE is online and FQDN settings are properly configured.  You must be able to ping named ping, like: ping www.eve-ng.net
2. Then from EVE CLI issue command:

systemctl restart licserver

3. After 15-20 seconds check License with with fix permissions command:

unl_wrapper -a dummy

It must show: Online Check state: Valid


Q: My EVE’s HDD is full. How to expand HDD space in the EVE?
A: It is achieved by adding new HDD to your EVE. Do not expand current HDD. Follow the guide to the link below.

NOTE: DO NOT Expand same HDD on VM machine you have !!!



Q: How to propely finish work with EVE and shutdown EVE ?

NOTE: If you are powering off your PC or server, but EVE VM is still running, you can have EVE Internal SQL database crash, which is following by, “I cannot login to he EVE WEB GUI”. To avoid it, please follow simple steps below:

Step 1. Save your work on lab nodes, like for Cisco router or switch nodes “wr”, for other vendors use their “save” documented commands.

Step 2. Stop all your running Labs

Step 3. As root user SSH to your EVE and execute cli command:

shutdown -h now

Now you are safe to power off your server or PC

If you caught this issue and cannot login in the EVE anymore, please visit EVE Live Helpdesk for remote support: https://www.eve-ng.net/index.php/live-helpdesk/


Q: How to recover my EVE-PRO or make backup copy ?
A: Please follow this How To: Recover or backupe EVE-PRO


Q: How to stop all running nodes by CLI ?
A: from the EVE cli type:

/opt/unetlab/wrappers/unl_wrapper -a stopall


Q: How to backup content of EVE-NG ?
A: For backup EVE content copy following folders:


Optional: if you had created own templates in EVE-PRO then backup data below as well.



Q: How to reset EVE management IP settings / DNS / NTP / Root password ?
A: from the EVE cli type:

rm -f /opt/ovf/.configured
su -

 Your EVE will jump to initial setup wizard.


Q: I cannot login in the EVE WEB UI?
A: Usually it can be 2 issues.

First issue is, if you have simply overloaded your EVE HDD. To check if HDD is not overloaded, please issue command:

df -h

Make sure if no one value is showing 100%. If so you must expand EVE HDD. Expansion of HDD is mentioned above or in EVE Cookbook.

Second issue is, if you had powered off your PC when VM ware and EVE VM was running. Same could happen if you had used suspend VM. These two actions can crash your EVE login database. To fix  database issue single line cli command:

unl_wrapper -a restoredb ; grep -q default_time_zone /etc/mysql/mysql.conf.d/mysqld.cnf || echo "default_time_zone='+00:00'" >> /etc/mysql/mysql.conf.d/mysqld.cnf ; systemctl restart mysql

To do not crash your EVE SQL database, use the following EVE cli command to properly shutdown it:

shutdown -h now


Q: My EVE after boot shows prompt (initramfs)>: ?
A: It looks like it is went something wrong with your EVE HDD system

First enter exit at the initramfs prompt.

(initramfs): exit

Take note of the path of the file system from the above image and shown below. Your root file system name will probably be different,
so use the information displayed on your system, which is used in the next command.

Example: The root filesystem on /dev/mapper/ubuntu-eve-ng–vg-root requires a manual fsck. Use the fsck command with the file system path determined above. This is in the following format.

fsck /dev/mapper/ubuntu-eve-ng--vg-root -y

Finally enter the reboot command at the (initramfs) command prompt.



Q: When in HTML5 console, I click on disconnect and got into a guacamole login page and can’t get any sessions in HTML5 now.
A: Logout/Login from/into eve to be able to open html console again.


Q: Why Qemu nodes are slow on my I7 64G ram ?
A: Typically, Antivirus deep inspection slows down Vmware Workstation and Virtual machines. Last observation was that even nodes (vIOS, CSR) running on EVE were under AV inspection. Avoid using AV on Vmware binary.

Q: How to upgrade my EVE?

A: run those commands on EVE CLI as root:

apt autoremove
apt update
apt upgrade

 (reboot if needed  – see homepage instructions )

IMPORTANT: after updating your EVE VM reboot it and CLEAR your browser cache.


Q: How to migrate from UNL to EVE? Is an upgrade possible?
A: No. The only way is to backup all images, labs etc from UNL, Install fresh EVE from ISO or OVA and restore backups.


Q: Why my wireshark doesn’t work?
A: You need to edit C:\Program Files\EVE-NG\wireshark_wrapper.bat file and change root password to match one you use.


Q: Starting more then 10 CSR gives CPU HOG. What to do?
A: UKSM is good for 10 CSR, if you want to launch more than 10 CSR, disable UKSM


Q: How to fix permissions?
A: Run bellow command from cli

/opt/unetlab/wrappers/unl_wrapper -a fixpermissions


Q: How to check which EVE-NG version is running from CLI?
A: Run those commands from cli for EVE-Community or EVE-Professional

dpkg -l eve-ng
dpkg -l eve-ng-pro


Q: What is the default username and password for EVE-NG?
A: CLI   – root/eve
WEB – admin/eve


Q: How to connect multiple nodes to the same network?
A: Add a network object to the lab topology and connect multiple nodes to it.


Q: What is CPU Limit Status?
A: It’s limiting CPU overload per node, but it does not involve common CPU utilization.


Q: My IOL nodes lost configuration in the NVRAM after upgrading to v2.0.3-53, what should I do?
A: Correct, if lab was created before version v2.0.2-23, IOL used old code with bugs which was fixed in later releases. new Version need re run node which will create new NVRAM for your IOL. Solution to keep your configurations: The best way if you have exported those configuration using export cfg feature. Then you can boot node after NVRAM wipe with your configuration in the new version of EVE.


Q: How to Reset/Recovery Web admin access?
A:  For community Edition, Type next 2 command lines in EVE CLI as Root user:

echo "DELETE from users where username = 'admin';" | mysql --host=localhost --user=root --password=eve-ng eve_ng_db
echo "INSERT INTO users VALUES ('admin',NULL,'root@localhost',-1,'Eve-NGAdministrator','85262adf74518bbb70c7cb94cd6159d91669e5a81edf1efebd543eadbda9fa2b',NULL,'','admin','',1);"| mysql --host=localhost --user=root --password=eve-ng eve_ng_db

This will add/restore “admin” account with password “eve” (without quotes)


A:  For Professionnal Edition (if you have EVE Pro version 2.0.6-1 and higher) , Type next 2 command lines in EVE CLI as Root user:

echo "DELETE from users where username = 'admin';" | mysql --host=localhost --user=root --password=eve-ng eve_ng_db


echo "INSERT INTO users VALUES ('admin',NULL,'root@localhost',-1,'Eve-NG Administrator','85262adf74518bbb70c7cb94cd6159d91669e5a81edf1efebd543eadbda9fa2b',NULL,'','admin','',0,-1,'internal',-1,-1,0,-1);" | mysql --host=localhost --user=root --password=eve-ng eve_ng_db

This will add/restore “admin” account with password “eve” (without quotes)


Q: How to fix error “Failed to lock the lab (60061) ?
A: Type next  command line in EVE CLI as Root user:

find /opt/unetlab/labs/ -name '*.lock' -exec rm {} \;