Hey @Deepak-Sharma

Try adding the "mode" to the command and see if that helps.

So...

find /usr/bin/ -perm -a=x (this gives you files with execute set for all modes <ugo>)

or you can just set the specific mode you want.

For User/Owner mode <u>

find /usr/bin/ -perm -u=x

for Group mode <g>

find /usr/bin/ -perm -g=x

for Other mode <o>

find /usr/bin/ -perm -o=x

Hope that helps :)

Cheers,
Daniel

@Adam-Gordon Thanks Adam!

You gave me a lot of food for thought. I'll be looking in the access tokens.

It looks like you might have some missing or corrupt files in your apparmor install. First, make sure you aren't out of disk space. Then, consider removing apparmor and then reinstalling it. I generally do a sudo apt remove apparmor followed by sudo apt purge apparmor and then reinstall with sudo apt install apparmor.

Modules are binary files that the kernel can load at runtime. They are not necessarily "installed" on the kernel, but they can be statically built into it during compilation (see: /etc/mkinitcpio.conf) if you want them to. Most of the time though, the module is loaded on-demand as required by the kernel.

Drivers are just modules that happen to deal with hardware components and devices, so you pretty much hit the nail on the head there.

Difference: Modules also deal with the software features side of things. The kernel by itself doesn't know how to read filesystems, encrypted storage or root partitions, or LVM setups. It needs to "learn" how to read and write in their languages in order to make meaningful sense of these 1's and 0's.

I haven't watched the Linux courses myself, but looking at the titles and content this is probably the surest route:

Before your course:

Getting Started with Linux (4.5 hours) Linux Essentials (8.5 hours) Becoming a Linux Power User (8.5 hours) Becoming a Linux System Admin (11 hours)

If you dedicate yourself to watching an hour of video per day every day, it would likely take you about a month to watch those four video series. You probably don't even need the "Linux System Admin" series before you take your Linux Administration course, but it would allow you to enter the course with a head start on the other students.

Then after your Linux Administration course:

Becoming a Linux Server Admin (12 hours) Linux Command Line (9 hours) Linux Shell Scripting - Basics (8.75 hours) Linux Shell Scripting - Advanced (8 hours) Linux Security Techniques (11 hours) CompTIA Linux+ (22.5 hours)

In this case, the $ means we are setting a default value for a session variable. It's confusing, but the $ is used for multiple purposes in Bash scripting.

Thanks,

Don

@WU-TANG and @Don-Pezet Sorry for late response. That answered it perfectly--thank you!

Sunny,

Localization is covered briefly as part of the "Installing CentOS" and "Installing Ubuntu" episodes at the end of the series. Cloud and virtualization concepts are covered in depth in the CompTIA A+ Core series.

Thanks,

Don

Michael,

The short answer is yes, you can do it. The long answer is that it won't be a very good firewall. There are a few obstacles you will have to overcome.

The Raspberry Pi only has one NIC. There is no "official" build of Ubuntu for the Raspberry Pi. Ubuntu is not natively designed to function as a firewall.

The first problem can be overcome a few ways. The easiest solution is to add a second NIC using a USB Ethernet adapter. This will put an increased power burden on your Pi so make sure you have a proper power adapter for it. Another issue you will run into is bandwidth. The USB pipeline on the Raspberry Pi is constrained. While it has one built-in NIC, that NIC is actually attached to the same bus as the USB ports, so your NICs will be competing with each other for access to the bus. Also, the Raspi does all of its NIC functions in software, so it isn't very fast. The most I have ever been able to push through a Raspberry Pi is 300Mbps, and that includes the new Raspberry Pi 4. You could help this out a little bit by using VLANs and building an 802.1q trunk to a switch, but now you are talking enterprise hardware and you could just buy a dedicated firewall.

The second problem is Ubuntu. There is no official build for the RasPi. You could run one of the unofficial builds, but I have found them to be slow and unreliable. That is a big deal for a security device. You could run Raspbian, which is an official port of Debian to the Raspi, but it wasn't designed with security in mind.

The last problem is native firewall functionality. Ubuntu was designed as a desktop first and a server second. Everything else falls by the wayside. That means if you configure pf or another firewall/router combination on it you will have to spend a good deal of time hardening the OS and removing unused features. That is why distros like pfSense and OpenWRT are so popular. They are designed as routers/firewalls from the beginning.

Personally, I use a Raspi as a personal server at home. It runs a web server, file server and email services alongside some tabletop gaming software and performs like a champ. My firewall, on the other hand, is running pfSense on a MiniITX board and handles my gigabit fiber connection without issues.

Hope that helps,

Don

Abhay,

The sudoers file contains a list of who is allowed to invoke the sudo command and what they are allowed to do with it. We can edit it a few different ways. You could easily run sudo vi /etc/sudoers and edit the file directly. However, if you make a mistake while editing the file, you could lock yourself out of the sudo command, which means you wouldn't be able to fix the error. That would be bad. So that is where visudo comes in. In addition to letting you edit the file, it also runs a syntax check on the configuration file to make sure it isn't broken. If there is an error, it won't let you save which ensures you will still be able to use the sudo command.

Thanks for writing in,

Don

Great. Your opinion is gold to me. Let's go back to the course :)

Thank you for your time helping me.

God bless you,
Ricardo

:wq!

I find that 9 times out of 10 sed and awk aren't necessary (which is good because sed and awk are hard). In this case, I would try to leverage some of the options in blkid to make it easier to get what you want. Try this out and see if it meets your needs:

echo "$(blkid /dev/sda1 -o value -s UUID) /mnt/Storage xfs defaults 0 0" >> /etc/fstab

In that example, I use blkid's filters to only return values for the drive I want that are tagged for the UUID field. Next, I use Bash's command expansion to build a string suitable to append to /etc/fstab. The result is a pretty straightforward command that doesn't require a lot of CLI-Jedi tricks to accomplish.

On a side note, remember that command expansion can behave weird when used in scripts. Running it on-off like you described will be fine, but in a script we would need to do the expansion in a variable first.

Hope that helps,

Don

@Don-Pezet So excited for LPIC-1! Thanks Don!

Sorry, the permissions should be fixed now.

There's a few things that can cause that problem. The easy one is that Webmin is run by just one guy so occasionally his repo goes offline. If that is the case you will get the error you posted. However, I just checked and it is online for me, so that may not be the issue. Double check your /etc/yum.repos.d/webmin.conf file and make sure there aren't any typos. It should look like this:

[Webmin] name=Webmin Distribution Neutral #baseurl=https://download.webmin.com/download/yum mirrorlist=https://download.webmin.com/download/yum/mirrorlist enabled=1

Then, try re-importing the certificates to make sure the permissions are correct. You can do that by running:

cd ~ wget https://download.webmin.com/jcameron-key.asc sudo rpm --import jcameron-key.asc

Let me know if it still doesn't work and we can dig through the syslog and see what else is going on.

Thanks,

Don

@Don-Pezet Exactly, looking for something like a bastillion. Thanks for help.

Thank you Don for your detailed explanation.