When you want to discover LAN metadata without being part of that network. So, when you want to discover network address range, gateway, DNS IPs, DHCP server IPs, etc. this simple nmap parameter will help you so much.
# nmap --script broadcast-dhcp-discover
Starting Nmap 7.60 ( https://nmap.org ) at 2021-05-19 15:07 CEST
Pre-scan script results:
| Response 1 of 1:
| IP Offered: 192.168.1.127
| DHCP Message Type: DHCPOFFER
| Subnet Mask: 255.255.255.0
| Renewal Time Value: 4d00h00m00s
| Rebinding Time Value: 7d00h00m00s
| IP Address Lease Time: 8d00h00m00s
| Server Identifier: 192.168.1.1
| Router: 192.168.1.1
|_ Domain Name Server: 18.104.22.168, 22.214.171.124
WARNING: No targets were specified, so 0 hosts scanned.
Nmap done: 0 IP addresses (0 hosts up) scanned in 1.43 seconds
Simple shell script based on bash which monitor a host with command line ping. Just bash and ping are the unique dependencies. Only state change are going to be printed:
echo "$(date '+%Y-%m-%dT%H:%M:%S') - " + $STATE;
ping -c 4 $IP > /dev/null 2>&1
if [ "$?" = "0" ]; then
if [ "$STATE" = "offline" ];
if [ "$STATE" = "online" ];
When you work with embedded systems sometimes you would feel happy to have a Linux box until you discover there are plenty of basic things that you don’t have available, the extreme of that could be the ‘ps’ command which is used most of the time for checking if any process is running . Maybe you know that thanks the /proc filesystem there is access to the source of the information.
Keep next command close for solving this inconvenience he next time:
Lately I bought a Surface Go for working specially as an agenda and for working outside home when I don’t have to work on technical stuff. At some point I considered the idea of working on that device remotely when I’m working with my desktop environment because it could be more comfortable specially because I have a bigger screen and keyboard for interacting with the content that I have on the tablet.
The first thing that I tried to do was enabling Remote Desktop Protocol on my Surface Go. But it was officially impossible because it has Windows 10 Home and the “Home” version doesn’t have this feature. BTW when you are not comfortable with this the best is googling little for finding any hack which allow me to enable the service. And yes, it exists and works really well.
You can find the project which hacks that in Windows 10 Home GitHub it’s called “rdpwrap” and if you want to know more about that go to next links:
After so much effort for getting RDP working on Windows 10 I discovered that RDP doesn’t work like Team Viewer, so you’re not going to control remote desktop while you can view what is happening in that remote session. This is not mandatory for me but in some cases it’s really useful. After some weeks I had to install Team Viewer for getting that feature working and I rediscovered that tool after some years without using it, and I was pleased to discover how good it works and how it improved after some years.
Then something inside me triggered the idea to look it up for an alternative to Team Viewer without so many restrictions and with a better free version. After trying some alternatives to Team Viewer I have to recommend Anydesk as an excellent and simple to use tool. And the most important thing, you don’t have to install anything in your Linux, Mac or Windows computer for using it. The only thing that you have to do is run the executable and use the auto-generated code for connecting to the remote system. I felt very good for those features and currently this is the option which I use for giving some support to friends remotely and for connecting to my Surface Go desktop remotely from my desktop computer.
As you can see this is not an exahustive revision, or comparsion of feautrues of all those three tools. But at the end of the day most of them allow you to do the same things but with slightly different procedures. BTW, the killer feature for me is something that I’ve got from “join.me” in the past, I mean use a tool for remote desktop control without having to install anything in the server and neither in the client part. I didn’t talk about “join.me” because it eats all my resources when I run it, and they focused the tool as a meeting tool and this is not anything that I want. Those extra features killed IMHO the best things that tool had in the past.
I’m a byobu user for a long time, I love it for many reasons. But this is just a quick tip for extreme users like me. I mean people who use byobu for local consoles with remote byobu sessions running on top of SSH, for instance.
When prefix key combinations has to be sent to the remote host we have to press “Control + a + a” and finally the command that we want to send to the remote systems. This is not comfortable many times. So, I modified my configuration file for changing the prefix when I want to send remote commands to the nested byobu.
This is going to work this way:
Control + a
as a prefix for local byobu session.
Control + b
as a prefix for remote byobu session
Take a look on this screen capture where you can see byobu status bars stacked.
If you find useful the configuration that I described the only thing that you have to do is modify the configuration file: ~/.byobu/keybindings.tmux
unbind-key -n C-a
set -g prefix C-a
set -g prefix2 F12
unbind-key -n C-b
bind-key -n C-b send-prefix
Do not expect something exception, or may be anything that nobody else has. Both services are very common and widely available on Internet but I usually have issues when I try to use them.
This is the same reason because I created https://url.joor.net, my own short URL service. Maybe you are asking yourself about which are the next two service that I created for myself; but I exposed to everyone on the Internet.
Firstly I’m talking about a service that returns your public IP address mainly focused to be used from a shell console, but also available by web.
curl -L ip.joor.net
And it only returns your IP address as a plain text, allowing you to do things so useful as assigning the IP address to a variable. Of course, if you access with your web browser is it going to work perfectly to.
Finally, I want to reference a file sharing service also oriented on being used in the console, but it works OK when you use the browser. IMHO, the WUI (Web User Interface) is too much basic and it will be nice if it was more basic user oriented. But the simplicity of the API is the most powerful value of this service and which it makes a Swiss knife in the console. I’m not going to say anything else about the service try it by yourself.
Usually, simple things are the best, in the case I want to recommend an FTP server for Windows. This is a really simple but super useful FTP server for Windows. I’m using in Windows 10 and it works perfectly. Configuration is done in less than 10″ and installation is not required, I love that. Super portable.
Don’t expect sophisticated options but the most useful and advanced ones are there. If you need something like that my recommendation is: