Install netcat with
sudo apt install netcat
or on RedHat based systems
yum install netcat
The below command will scan all the ports up to 1000. Change if needed.
nc -v -z 192.168.1.20 1-1000
Port scan with Netcat
Reply
Install NextCloud on Ubuntu 19.04
Install with snap
sudo snap install nextcloud
Set user and password for NextCloud
sudo nextcloud.manual-install nextcloudadmin password
Allow https access for firewall
sudo ufw allow 80,443/tcp
For the following steps to work, you’ll need an A record setup on your domain name server to point a domain to your Next Cloud servers public ip address. Change www.example.com in the following steps to the domain name you’ve setup.
View trusted domains
sudo nextcloud.occ config:system:get trusted_domains
Setup new trusted domain. Change www.example.com with your domain.
sudo nextcloud.occ config:system:set trusted_domains 1 --value=www.example.com
Run through Lets Encrypt to setup a SSL certificate.
sudo nextcloud.enable-https lets-encrypt
Should be able to access NextCloud from a web browser www.example.com
Recovery, Your PC/Device needs to be repaired
File: \EFI\Microsoft\Boot\BCD Error code: 0x000000f The Boot Configuration data for your PC is missing or contains errors.
The following notes may be of some help when trying to resolve the above error. Think the primary issue had to do with cloning a GPT drive to a RAID array that was using MBR. So think everything worked after converting it to GPT
All the commands are/were run from a recovery Command Prompt
Convert MBR disk to GPT
After running the following command the EFI directory was automatically created.
The command is supposed to be non destructive. Change the disk to whichever disk your trying to change to gpt.
gpt2efi /validate /disk:0
Other commands
If running the above command did not work then you may give the following command a try. Change the drive names where appropriate.
bcdboot c:\windows /s s: /f UEFI /vYou may be able to get away with just using
cdboot c:\windowYou can check if the above worked by seeing if it created any files in the directory, if new efi partition is S:, then from a command prompt run
S:
dir
Commands for recreating the EFI partition (WARNING! MAY DESTROY DATA!)
diskpart list disk select disk # Note: Select the disk where you deleted the EFI System partition. list partition create partition efi format quick fs=fat32 list partition list volume
How To Reset root Password on CentOS VM – XenServer
Basic steps are as follows.
- Shutdown VM
- From XenCenter, insert the CentOS iso into the VM’s Virtual DVD drive.
- Boot the CentOS VM in recovery mode. If you need help with that check this post out.
- On the grub menu, select recover OS Installation.
- Run through the recovery and mount the VM’s disk where CentOS is installed
- You should now be able to drop to a prompt and chroot /sysimage
- Change the root password with passwd
- Shutdown the VM
- Eject the CentOS iso
- Boot up the VM and login with the new password
Set static ip address in Ubuntu 19.04
The network configuration settings for the server edition of Ubuntu are now stored in the following location. Create the file if it does not exist.
sudo vi /etc/netplan/01-network-manager-all.yaml
Add or edit the config file to the following. Change eno1 to your interface name and the address and gateway to the appropriate IP’s
For more information, see netplan(5).
network:
version: 2
renderer: networkd
ethernets:
eno1:
dhcp4: no
addresses: [192.168.200.24/24]
gateway: 192.168.200.1
nameservers:
addresses: [8.8.8.8,8.8.4.4]
Now apply the changes with the following command.
sudo netplan apply
OpenVas set password for user
After installing OpenVAS you may need to setup a user. Running the following command will create the user admin and will print the password for the user below.
openvasmd --create-user admin
Example output.
User created with password 'b4539967-c521-fe41-d255-aeb53e735h9a'.
If needed you can delete a user with the following command
openvasmd --delete-user=USERNAME
LibreNMS – Remove unused Geo locations
Access all the locations in LibreNMS by clicking on “Devices > Geo Locations > All Locations”
This will bring up all the locations in LibreNMS. To remove a unused location, hit delete. Note: to be able to delete a device, there must be no devices using that location.
Verify Ubuntu iso on Windows
On Windows you can use the CertUtil utility to verify an iso image.
First, you’ll need the checksum of the iso. Should be on the page where you downloaded the iso. More info about that here.
Next generate the hash by running the following in a command prompt. Replace the path and ISO name with the one you downloaded
certutil -hashfile Downloads\ubuntu-19.04-live-server-amd64.iso sha256
Example output
SHA256 hash of Downloads\ubuntu-19.04-live-server-amd64.iso: 25d483341ccd0d522a6660b00db933787c86c47b42f1845bcf997127f4b61e9d CertUtil: -hashfile command completed successfully.
Compare the output with the checksum. If they are the same, you should be good to go.
Raspberry Pi – Ping IP Address and Toggle LED
The following script is for monitoring if an IP address is reachable or not. If it becomes unavailable the script will turn on a LED that is plugged into one of the GPIO pins of the Raspberry Pi. View pinout here
Script
#!/bin/bash
# Script to ping ip address and turn on LED on if device is unreachable.
nPin="18" # Change if GPIO pin is different
ledPin="gpio${nPin}" toPing="8.8.8.8" # Change to address you want to ping
echo "${nPin}" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/${ledPin}/direction
if ( fping -r1 $toPing | grep -v alive ); then
echo "Internet unreachable"
# Turn on LED
echo "1" > /sys/class/gpio/${ledPin}/value
else
# Turn off LED
echo "0" > /sys/class/gpio/${ledPin}/value
fi
Save script as ping_led.sh and make it executable.
chmod +x ping_led.sh
and run the script.
sh ping_led.sh
Run script in crontab
You can setup the script to run every minute using a crontab
crontab -e
Add the following line
*/1 * * * * /home/pi/ping_led.sh
Should now execute the script every minute and not need any human interaction.
LibreNMS manually adjust GPS coordinates for a Geo Location
The locations are stored in the LibreNMS locations table
mysql -u librenms -p librenms
To list all the locations
select * from locations;
Set the specific coordinates for a location using the following command.
Replace the lat and lng, also the id should match the line your wanting to update.
update locations set lat = "33.5140",lng = "-86.8178" where id=25;