- You know, I've been in
this industry for a long time and over the years you
learn many tips and tricks. But there's a much quicker way
of learning a bunch of stuff than just many years of experience. And the way to do that is to find someone who knows something or
has learned something and can teach you. So in other words, find mentors. Now, I'm gonna be creating
a series of videos where I want to help you become a better network engineer. Don't spend 15 years like I have, having to learn all these
tips and tricks the hard way. Just learn from these videos. So hopefully the tips and
tricks that I'm gonna show you in this video and subsequent videos will make you the so called
Ten-X network engineer. In other words, you'll
become a network engineer that's set apart from others. You're gonna learn some
commands in this video that I wish I had known many years ago. Use these commands to set you apart from others in the industry. When you go for an interview or when you have a senior
network engineer or someone else watching what you're doing, use these commands and amaze
them with what you can do. In this video I'm gonna show you how you can leverage a Linux
commands classic Cisco IOS. Now, I'm not talking about
dropping into Linux shell. I'm not talking about enabling a Linux VM or Linux shell separately
from the Cisco IOS. These commands run
directly within Cisco IOS. This is classic Cisco IOS. In other words, the
IOS that's been running on network devices for many, many years. I've tested this on multiple devices. I'm gonna use GNS3 in this example, but I'll also show you that these commands work on older
devices like 1900 routers. So use these commands to get ahead to show others that you know stuff that many others in the
industry don't know. Hopefully you'll enjoy this video. If you do, please like it and please consider subscribing
to my YouTube channel. That really does help me. Okay, you're ready to learn some really cool Cisco IOS commands. Let me show you what's possible and show you how you
can set yourself apart from others in the industry. Okay, glasses on because I'm old. (upbeat electronic music) Okay, so here I've got a Cisco
IOS router running in GNS3. "show version" shows me that this is VIOS. Here's the version of operating
system on this router. Now some of you may already
know some of these commands. As an example, "sh ip int brief" shows me interfaces on this router. But notice here, I have got
many many loopback interfaces. So I've got my physical interfaces. So gigabit 0/0, 0/1, 0/2, 0/3. But notice here whole bunch
of loopback interfaces. Now there are plenty of these. I'm gonna use forward slash now. That command is available in Linux. You'll find it in VI, as an example. So here's a Linux device. "Uname -a." Notice I'm running Linux here. This is an Ubuntu Linux PC. It's actually a docker
container running in GNS3. But what I'll do here is start VI. And I've got a file
here, which is actually a show run of a switch configuration. Notice when I use forward slash, I can filter as an example for face. I can filter again for line and that just scrolls through the configuration to that point. I'll put out a VI here. So this forward slash allows me to filter, as an example, for 192. It's gonna take the show
IP interface brief command and filter it, notice
filtering, up to that point. Notice Loopback192. I'll filter again because
what I'm actually looking for is this Loopback300 interface starting with 192.168.100.1
as the IP addresses. And there's a whole bunch of these. I'll filter again for,
let's say UN, as in tunnel. And notice it filters all
the way down to tunnel. Now, I have shown this forward
slash command in other videos but that's not what I wanna show you here. I'm gonna show you a really cool command. Notice I'm gonna go into
global configuration mode and type "shell processing full". So I've enabled full shell processing. That's the only command that you need. And notice what I can do now. So rather than doing it that way, like show IP interface brief, and then having to filter
through the configuration looking for interfaces, I'm gonna type "show ip int brief" and notice what I'm gonna use here. Grep. Grep is a Linux command that allows me to filter or search for stuff. Now, some of you may already know include. I could include, let's say 192. And that shows me all the
lines that include 192. But that include statement
is quite limiting. I can only do one include. I can only search for one thing. But notice what I can do here. I can do a grep for let's say up. So I'm looking for all
interfaces that are up. Now, that's a bit boring because it's just gonna show me every interface that's up. But what I'm gonna do now is do "| grep" and let's not show
interfaces that include 172 and let's also not show 192. This is a three-tiered grep. I'm doing a search for something and then I'm excluding something and I'm excluding something else. So I'm doing a three-type
include as an example. You can't do that with the
standard include commands. Notice this shows me interfaces
that have up in the list. So these interfaces are up but I'm not seeing 172 and 192. I've just filtered a
whole range of interfaces and all I'm seeing are
the gigabit interfaces and then these tunnel interfaces and I've got two loopback interfaces here in the 10.100 range. So that's really powerful. I could do another one here. So let's remove those. So let's say "grep -v" and
I could just do it this way where I could say remove loop. I don't want loop. And notice that just shows
me gigabit interfaces and tunnel interfaces. Now some of you may say, "Well you could just do that once." And that's true. Just play around with the commands and see what works for you. So I could just do grep up. "Grep -v loop." So show me interfaces that have up in them but don't show me loopback interfaces. So that's a positive and
negative grep of output. You try and do that with
just include commands. Now you may be able to do some of that but let's show you an example on a switch that may really help you. "Show ip int brief." This will show me
interfaces on the switch. I can see gigabit interfaces. I can see vlan interfaces. Some of the interfaces are
up, some of them are down. But what I could do is say show me interfaces that are up but don't show me
interfaces that don't have an IP address assigned on them. That can be really useful if you've got a large configuration
and you only wanna see interfaces that have an IP address on them and that are up. Okay, so how about "show run grep 1.1". Now that dot is actually
a regular expression. Notice we've got a
matching character there. We've got a matching character
here, here, and here. What I could do however is say grep again for let's say 10. So show me everything that has 1.1. In other words, one something one in it. But filter that to only show me the lines that have 10 in it. So something like this. Now you might say, "well, I
could have just done include 10" as an example. And that's true but
don't use these examples to limit what you're thinking. Use these examples just to
show you what's possible and then think out of the box. How can you use this? Try different things and
see if you can think of ideas of how you can use these commands and add them below this video. Tell me examples that you've found useful. Now, notice I can do an include but I can't do an exclude here. So with grep I can do that. So the include, exclude
option is kinda limiting. But with grep I could say show me that but let's do -v, let's exclude gig. And that's probably because
I didn't use grep there. So, "grep -v Gig". Notice same kind of result
as I had over there. This is a double include,
if you like, or double grep. Show me something that matches twice. Here I've got show me a matching line but don't show me this line that matches. So we've got an include/exclude. You can't do that with the traditional show run pipe include,
show run pipe exclude. Here I'm doing include/exclude
at the same time. Okay, so let's look at
some other Linux commands. Here's my Linux PC once again. So "uname -a" shows me
that I'm using Linux. "--help" gives me help
options with this command. But on a Cisco device as an example, I can type "uname -a". This shows me that I'm
using IOSv, as an example. Now just like in Linux, I can use man. So look at the manuals. So give me details of uname. Notice lots of options
available with uname. So "uname -a" shows me all the information about this router. S just give me the version. So it's IOSv. N gives me the name of the router. But let's try R. That's the version of operating system. So if you just wanna get the
version of operating system, there you go. That could be useful in
a script as an example. Or V gives me details of the version. Very similar to the
output over here with -a. Now again, Linux does
something very similar. I could say "uname -a",
gives me all the output. S tells me that this is Linux. This shell option has many commands. Now you may be wondering what kind commands are supported? I don't wanna make this video too long. I will show you some more complex
stuff in a separate video. But if you wanna start investigating what options are available, we have this "show
shell functions" command that will show us which functions are supported by this command. So notice a very basic one, cat. We've got cut. We've got echo. We've got grep, which I've
been showing you at the moment. It says, "search for regular expressions "in piped output or files." We've got head, more. Plenty of Linuxed commands available here. So let's use head and tail. So, "sho run | head" will
show me the first 10 lines of the running configuration. So there you go. So first few lines of the
running configuration. I could also say tail, which will show me the last few lines of the
running configuration. That's very basic stuff. Cat allows me to read a file. So if I type "dir", notice
there's some files in flash. Let's do this. Show run, and this is
very much a Linux command. I'm gonna pipe the show running
configuration to shrun.cfg. So I'm gonna type show run,
pipe that configuration, or push that configuration
to a file in flash. So dir shows me that that
file exists in flash. And what I can do here
is type "more shrun.cfg". And notice there's the file
that I'm reading from flash. But how about this? Let's do "sh IP route". And actually let's push
that to shiproute.txt. So, that file once again exists
in the flash of the router. So what I'll do here is use cat. So, "cat shiproute.txt". Cat just shows you the
whole file in one go. Notice there are a lot of routes here. So I may have preferred to use more. More shows me one line at a time rather than just showing you
the whole output in one go. So while we're waiting for that, let's go back into Linux. So clear. LS shows me the file here. "Cat shrun". Those shows me the running
configuration in one go. So that was a bit quick. So notice, "cat shrun", whole configuration in one go. I could do more. Notice that shows me one page
of configuration at a time. Same here. Rather than using cat, I
may prefer to use more. So I'm reading that file from flash. But what it allows me to
do here is press q to quit. So rather than seeing all that output, I could just see one page
at a time and then quit. Okay so I could go on
for a long time here. Notice we are using classic IOS here and I was able to use these commands by just running the shell
processing full command. Now in other videos I'm going to show you even more powerful ways of leveraging this to make you stand out from the competition as a network engineer. So learn this stuff and
hopefully it will save you a lot of time in the real world. It will help you become a
better network engineer. And it'll help you differentiate yourself from others in the industry. Now hopefully this is gonna
change the way that you work. Hopefully it's gonna separate you from others that you work with or others in interviews. Hopefully it will show
people that you work with that you're serious and that you're an
excellent network engineer. Once again, if you don't mind, please subscribe to my YouTube channel and please like this video. I'm David Bombal and I
wish you all the very best. (upbeat electronic music)
