October 21, 2025 • 25 mins
Ever wish the network would just explain itself? We walk through the real language of connectivity—how links come alive, how packets choose their paths, and how a few core ideas unlock routers, firewalls, addressing, and the exam questions that test them. It starts with the wire (and the air): DSL over copper, cable scaling with DOCSIS, fiber to an ONT at your home, and why fixed wireless, satellite, and 5G fill coverage gaps with very different tradeoffs in speed and latency. From there, we draw the line between moving traffic and governing it. Routers forward based on IP and subnets; firewalls enforce policy using IPs, protocols, and ports—think velvet rope, but for packets.
We bring the TCP/IP stack down to earth with a clean mental model of layers and encapsulation, then dig into IPv4 addressing, subnet masks, and private ranges that rely on NAT to share a single public IP. You’ll learn why static IPs belong on printers and servers, how DHCP’s DORA flow keeps clients online, and what APIPA is telling you when a lease fails. We also size up IPv6—128-bit addresses, hexadecimal notation, dual stack—and unpack the practical roadblocks that slow adoption despite the promise of massive address space.
Transport choices make or break performance, so we compare TCP’s three‑way handshake and delivery guarantees with UDP’s low-latency approach favored by streaming and gaming. We highlight the ports every tech should know—22, 53, 80, 443, 67/68, 21/20, 3389—because port literacy speeds troubleshooting. On identity and isolation, we translate DNS records (A, AAAA, CNAME, MX, TXT) into everyday use and show how VLANs reduce broadcast noise while VPNs protect data over untrusted networks. To cement it all, we run live quiz walkthroughs and model how to spot keywords, eliminate distractors, and reason under time pressure—skills you can carry straight into the CompTIA A+ and beyond.
If this helped you think more clearly about networks, follow the show, leave a rating, and share it with a friend who’s studying. Got a topic you want us to deep-dive next—DHCP, DNS, or VLANs? Drop a note and subscribe so you don’t miss the next breakdown.
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Music by Joakim Karud
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
SPEAKER_01 (00:27):
And welcome to Technology Tap.
I'm Professor J-Rodd.
In this episode, The Language ofNetworks, I just think,
Connections, and Communication.
Let's tap in the world.
(01:06):
Welcome back to Technology Tab,where we keep tapping into
technology.
I'm Professor J.
Rod, and today we're decodingthe language that keeps every
network alive (01:14):
addressing and connectivity.
Whenever you're installing arouter at home or supporting the
hundreds of users in anenterprise, the same
fundamentals apply.
IP addressing, ports, DACPs,DNS, VPNs, and VLAN.
This episode follows the modulefor the Compia core exam, and by
(01:35):
the end, you'll see how everypacket knows where it's going
and how it gets there.
Internet connection types frommobile from modems to fiber.
Every internet session beginswith a modem, the bridge between
your network and your internetservice provider.
DSL, digital subscriber line,runs over regular phone lines.
Asymmetric DSL is fasterdownload.
(01:57):
Symmetric DSLs keep speed equalsfor businesses that upload data
consistently.
Cable modems.
That's why upgrading to DOS Sys3.1 can bump you from 300
megabits per second to 1 gig.
Fiber to the premise.
(02:18):
Pure glass from the providerstraight to your home or
business, terminating at an ONT,optical network terminal.
Wireless and cellular.
Imagine a rural repair shop toofar for cable or fiber.
It might use a fixed wirelessthrough a wireless ISP or WISP.
Satellite, like the Starlink LEOLEO constellation, offer lower
(02:40):
latency alternative togeostationary orbit.
And on the go, cellular networkshave revolved from 3G CDM to 5G
with massive MIMO enablingspeeds once reserved for
wirelines.
Routers and firewalls.
Your router makes IP-basedforwarding decisions determining
which interface each packetuses.
(03:02):
Meanwhile, a firewall enforcesrules known as access
controllers.
Filtering traffic by IP, Mac,protocol, or port.
Think of it as a bouncerchecking IDs before anybody
enters the network club.
Here's an example.
A rule that says allow TCP 443from any internal web server
permits encrypted HTTPS trafficbut blocks everything else.
(03:29):
The four layer model.
The TCP IP is a suite ofprotocols with layers.
One, link layer, framestraveling using MAC address.
2.
Internet layer, routing packetsvia IP address.
3.
And 4.
The application layer protocolslike HTTP and DNS.
(03:52):
This TCPIP 4 layer model issimilar to the OSI model.
The OSI model, as you know, hasseven layers.
The TCPIP model has only fourlayers.
Each layer wraps the data in itsown header, like stacking
envelopes inside envelopes.
IPv4 masking and addressing.
(04:12):
An IPv4 address is 32 bits long.
Four octaves, eight bytes each.
Four times eight equals 32.
So for example, 192.168.1.25.
Each octave, so for example, 192will be considered an octave,
has eight bits.
168 has eight bits.
(04:33):
One has eight bits.
What do you get the number from?
The number, and I'll have to doa deep dive, a little bit of a
deep dive on this.
The number depends on how manybits you turned on.
Which bits you turn on.
So there's certain bits, youknow, there's eight, the eight
bits are 128.68, 32, 16, 842.1.
And so 25, you would have 16 on,8 on, and 1 on.
(04:58):
So that's the example.
But I'll do a little bit of adeep dive on another episode
about IP addressing.
It cannot be done.
It has to be its own separatetopic.
Uh the setnet mask devicenetwork ID and host ID.
Example 255.255.255.0 means thefirst three octaves identify the
network.
(05:18):
Public versus private.
Private range uses inside lens.
Use the class A is 10.0.0.0.
For class B, the range is172.16.0.0 to 172.31.255.255.
(05:38):
For class C is 192.192.168.0.0.
The router performs NAT ornetwork address translation,
mapping private address topublic ones.
That's a hundredths of device,share one internet IP.
Again, this is another topicthat's going to have its own
segment because it's just too,you know, I can do 23 minutes
(06:03):
just on public-privateaddressing.
So that'll be its own separatething.
So example, your phone192.168.1.50 says request.
The router translates it to7575.32.18.7 on the internet.
Uh the reply returns and is DNATback to you.
(06:25):
Static, dynamic, and uh PIPA.
Static IP, you manually enterit, useful for printers and
servers.
Usually you want to use staticIP for uh devices that are never
going to change, that you don'twant the IP never to change.
So you know, your printers, yourservers, your routers, maybe a
managed switch, right?
(06:46):
Those are devices that you neverwant to change.
So it's fine.
Uh DHCP automates addressassignments through Dora.
Discover, offer, request,acknowledge.
These are for like yourworkstations, right?
Things that you don't care ifthe IP address changes.
You know, pretty much yourworkstations, you don't really
care if the IP changes.
(07:07):
There's no you don't need tohard code your workstations.
And a PIPA is when the addressstarts with 169.254, appears
when DHCP fails, Windows way tostay local when disconnected.
IPv6, which is going to be thenew standard of internet
(07:30):
addressing, when is that gonnahappen?
Who knows?
I've been hearing about IPv6 forthe last 10 to 15 years.
Yeah, I don't know when it'scoming.
Coming soon, it's like forever.
So, what's the biggest obstacle?
I'm pretty I'm pretty sure it'smoney.
And why?
You know, why at this point, ifeverything's working, why change
(07:53):
it?
And then in order to change it,you know, it's gonna cost it's
gonna cost money, it's gonnacost time.
You gotta get these texts tomake all these changes.
That's that's gonna cost money.
But anyway, IPv6 uses 128 bits,hexadecimal notation, and
colons.
So an IP address can be let'ssay 2001 0 dB858300, colon 8A2E,
(08:27):
0370, 7334.
Dual stacking lets Ipv4 and IPv6run side by side.
Organizations adopt IPv6 for itsnearly limited address space.
I don't know anyone that isactually using it, but again,
it's coming soon.
(08:48):
You have your protocols andports.
TCP and UDP uses ports from zeroto sixty five thousand three
hundred to differentiateservice.
TCP is connection-oriented,which is reliable.
UDP is connectionless, faster,but no guarantees.
UDP is like Netflix, YouTube,right?
A lot of data going back, youknow, send me the data, send me
(09:09):
the data, send me the data,right?
TCP is like email, logging intoa website, right?
So some well-known ports that wehave out there that you know you
may need to learn.
FTP file transfer port codesuses port 2021 and is TCP based.
SSH, port number 22, TCP based,DNS 53, it's UDP and TCP based.
(09:35):
HTTP is 80 port, uh port 80 andit's TCP based.
HTTPS uh port numbers 443 andit's TCP based, DHCP, port
numbers 67 and 68, and it's UDPbased.
And RDP remote desktop is 3389TCP-based.
(09:57):
When you're visiting a websiteusing HTTPS, your browser
initiates a three-way handshake: sync, sync act, and act to (10:01):
undefined
establish a reliable connection.
Sync means synchronization andact means acknowledgement.
So it's synchronization,synchronization,
acknowledgement, and thenacknowledgement.
A real world example is a gamestreaming platform may use UDP
for real-time videos becausedropping a few frames is better
(10:23):
than delaying the stream.
Just like Netflix, right?
Dropping a few flame uh framesin Netflix is better than
delaying the film.
So and they use UDP.
Network configuration concepts,DHCP functions.
A DHCP server manages scope,leases, and reservations.
(10:44):
If you reserve a MAC address,that device always gets the same
IP.
Perfect for printers or securitycameras.
DNS, the phone book of theinternet.
The domain name systemtranslates names into IPs.
When you type, you know,www.google.com, right?
It resolves to something like8.8.8.8.
(11:07):
A record type should know Athrough quadruple A is IPv4,
IPv6, C name is your alias, MXis always for mail server, and
that's a clue for the Camtiatest, right?
If you see a question and thequestion that they ask you has
the word MX in it, just look formail server or email.
(11:29):
It's usually that's usually whatthe answer is.
And TXT or text uh verificationor SPF data.
Example DNS lookup follows achain root server, right?
Then the top level domain, andthen the authoritative server,
and then your answer VLANs andVPNs.
(11:51):
VLAN or virtual LAN segment aswitch into isolated uh
broadcast domains.
For instance, separating financetraffic from students in a
capitalist network, and thenyour virtual private network
creates an encrypted tunnel overpublic Wi-Fi.
Example, when you connect yourcollege VPN, all traffic to
internal servers is secure, evenif you're in a coffee shop.
(12:12):
Again, this some of this stuffwe would have to expand on it.
It's just you know, to do theseshort snippets that I'm trying
to do, especially with thequestions at the end and the
allotted 23 minutes, 24 minutetime that I want to get to.
It only gives us time for thesesnippets.
But I will do like a deep, deepdive into DHCP, DNS, VLANs.
(12:37):
I'm you know, that needs thatdeserves you know, a
public-private address, all thatstuff deserves huge deep dives,
separate podcasts on its own,separate episodes.
I'm following the the like whatCertmaster gives you, which
honestly doesn't really give youa lot as far as the PowerPoints
(12:58):
is concerned, and that's whatI'm using just to just for quick
snippets.
But to be fair, I have to, ifI'm gonna, you know, be a good
instructor or a good teacher, Ihave to give you the full
definition of what DHCP does.
And I have a whole thing, I youknow, if my if you take my class
(13:19):
and I've gone over DHCP, youknow how I do it.
I do a whole scenario and stuff,and but it deserves its own
episode.
You know, a couple of thesethings, now that we're getting
into the meat of A plus, itdeserves its own, its own uh
(13:59):
episode.
Some of these stuff is just toobig to cover in snippets.
So all right, let's do thequestions.
All right, so if you're new tothis, the way I do it is I ask
the question, I read thechoices, and then I do it again.
I give you five seconds and youtry to guess if the answer is
right.
(14:19):
Question one Which internetconnection typically uses an
optical network terminal at thecustomer's presence?
A DSL, B, cable, C fiber to thepremise, or D satellite.
Again, which quet which internetconnection type typically uses
the optical network terminal atthe customer premise?
A D DSL B cable C fiber to thepremise or D satellite.
(14:43):
I'll give you five seconds tothink about it.
Five, four, three, two, one.
And the answer is C, of course,fiber to the premise.
Connections terminate at an ONTthat converts optical signals
into internet for use inside thebuilding.
And ironically enough, ladiesand gentlemen, if you took my
(15:04):
classes years back, I wouldalways say there was, you know,
there's no way they would putfiber in your house.
But now they do.
They actually do put fiber inyour house, which I find amazing
that they do that because fiber,if you know anything about
fiber, it's very, very delicate.
I have a Verizon 2G, and there'sactually a fit of uh fiber cable
(15:28):
inside my house, which I neverthought they would do.
I would never throw they woulddo, but it's there, so I just
gotta be careful not to uh breakit.
All right, question twoaddressing.
Which IPv4 address range isreserved for automatic private
IP addressing or a PIPA?
A 10.0.0.0 slash eight, b169.254.0.0 slash 16, C
(15:56):
172.16.0.0 slash 12 or D what192.168.0.0 slash 16.
I'll read it again.
Which IPv4 address range isreserved for automatic private
IP addressing or a PIPA.
A 10.0.0.0 slash eight b169.254.0.0 slash 16 C
(16:24):
172.16.0.0 slash 12 or D192.168.0.0 slash 16.
I give you five seconds to thinkabout it.
54321 and the answer is B169.254.0.0 slash 16.
(16:46):
Windows assigns a PPR address inthe 169.254.0.0 to
169.254.255255 range when noDHCP server is available.
See, this is what I mean.
Like that is something that Ineed to explain more.
Right?
So maybe the next episode of A,I will go into a whole deep dive
(17:11):
of what DHCP is, how it works,you know, fully, fully express
explain it, break it down.
I think I do a really good jobof breaking it down for my
students for DHCP, you know,using a scenario that
everybody's familiar with.
And then that way they, youknow, you can they you really
understand how you know thingswork, right?
(17:33):
Because we're getting into thegranular level of things, and
you really need to know howthese things work, especially if
you're gonna take the A plusclass.
So, and I'm gonna do a lot moredeep dives on the on the A plus.
All right, protocols and ports.
A network administrator wants tosecure remote logins by encrypt
by encrypting traffic.
(17:55):
Which protocol and port shouldthey use?
A telnet port number 23, B SSH,port number 22, C HTTP, port
number 80, D FTP port number 21.
Again, I'll read it again.
A network administrator wants tosecure remote logins by
encrypting traffic.
Which protocols and ports shouldthey use?
(18:16):
A telnet slash 23 or port number23, SSH port number 22, HTTP
port number 80, or D FTP portnumber 21.
So this is uh here's how youwould tackle this question, and
this is part of the CAMTIA way,right?
If you look at the question, ifyou listen to the question,
(18:37):
because you can't look at it, ifyou listen to the question, you
will see that it says a networkadministrator wants to secure
just that word secure, that'sthe clue in the question,
secure.
So out of all of these, whichone could you eliminate right
away?
Well, HCTP is not secure, sothat's our right telnet.
(18:58):
If you know anything abouttelnet, that's not secure.
That's out, right?
And then you're left with SSHand FTP, and then wants to
secure remote logins.
The answer is B, SSH.
Right?
SSH encrypts remote terminalsessions, unlike telnet, which
sends data in plain text.
(19:19):
So there's also like a about, Idon't know, 20, 22 of these
ports that you need to know forthe exam.
I will also do a deep dive onthat.
It's important that you knowthese, and once you know them,
it scaffolds, right?
So this is the good thing aboutCompTIA, and this is the good
thing about taking a CompTIAexam at A plus, at the A plus
(19:42):
level, and not skipping toSecurity Plus like right away,
right?
There's some people who whoright away they don't they don't
do anything, they don't theydon't never worked in in PC
before.
Maybe they fixed their friend'sPC, right?
They're that one guy, butthey've never really, really
worked in IT.
So they want to jump all the wayto security, and the and that
(20:02):
that test is really hard.
I mean, there's people who'vedone it, and I've known two
people who have done it.
But both former students, butmost people can't.
I mean, you really, really,really gotta be dedicated if you
want to take a security pluscourse or study on your own.
I know one young lady whostudied on her own and she
(20:25):
passed, and then one took aclass with me and he passed.
But it's not it's not an easyexam, and to just try to jump in
the line is kind of difficult.
But if you start at A1, uh A, itscaffolds.
So you go to network plus, like50% of network plus is in A, and
like 30% of security plus isn'tA.
You know, you know, so you knowyou learn the foundation, and
(20:47):
it's better to start at A.
I don't know why people want tojump the line, but that you
know, that's them.
All right, last question: network configuration. (20:55):
undefined
What is the primary purpose ofvirtual LAN or VLAN on a managed
switch?
A to provide wireless coveragein large area, b to segment
network traffic for performanceand security, C to encrypt
tunnels over the internet, or Dto assign dynamic IP address to
(21:16):
clients.
I'll read it again.
What is the primary purpose of avirtual LAN or VLAN on a managed
switch?
A to provide wireless coveragein large areas, b to segment
network traffic for performanceand security, C to create
encrypted tunnels over theinternet, or D to assign dynamic
(21:37):
IP address to clients.
Now, you have a before youtackle this question, if you
listen to it, there's a coupleof clues here.
One is manage switch, right?
So anything that has to do withIP addresses, it's out because
switch does not manage IPaddress.
So D is out to assign dynamic IPaddress to clients, that's out,
(22:01):
right?
So you left with to providewireless coverage in large areas
to segment network traffic tofor performance and security and
to encrypt network tunnels overthe internet.
Nothing to do with the internet,a switch does not do anything
with the internet, C is out.
So you're left with A and B, andthe answer is B.
VLANs divide a switch intomultiple logical networks,
(22:22):
isolating traffic and reducingbroadcast domain for better
performance and security.
That's how you tackle A plusexam.
Just like the way I did it.
Just look at the question.
Not every question is going tohave a clue because a lot of
them is gonna say, hey, what'sthe port number for Telnet?
Right?
So that there's no clue in that.
(22:44):
Either you know it or you don'tknow it.
But some have clues.
And you look at the clues fromjust reading the clue, reading
the question, you gotta dissectit, right?
That's what I call it.
You gotta dissect the question.
And but you only got a minute todo it.
You don't have a lot of time,you gotta like average like a
minute of question.
(23:04):
So I always tell my students, gothrough the exam first, the
first time, answer the questionsthat you can answer, right?
If you answer the questions thatyou think you can get it right,
answer those and then go backand then answer the rest, and
then take your time because youcan answer a question that you
know like 10-15 seconds.
So then that you know that willhelp you 100%.
(23:28):
Alright, let's wrap this up,guys.
From DSL to DNS, from IPv6 toVPNs, you now understand how
iDressing keeps the internetorganized.
That Comp Tia test doesn't justtest your memory, it tests how
you think through connectivityproblems.
(23:49):
I'm Professor J.
Rod, and I just want to remindyou stay curious, stay secure,
and always keep tapping intotechnology.
(24:34):
This has been a presentation ofLittle Cha Cha Productions, art
by Sarah, music by Joe Kim.
We're now part of the Pod MatchNetwork.
You can follow me at TikTok atProfessorJrod at J R O D.
Or you can email me atprofessorjrodjr-od at gmail.com.
And welcome to Technology Tap.
I'm Professor J-Rodd.
In this episode, The Language ofNetworks, I just think,
Connections, and Communication.
Let's tap in the world.
(01:06):
Welcome back to Technology Tab,where we keep tapping into
technology.
I'm Professor J.
Rod, and today we're decodingthe language that keeps every
network alive (01:14):
addressing and connectivity.
Whenever you're installing arouter at home or supporting the
hundreds of users in anenterprise, the same
fundamentals apply.
IP addressing, ports, DACPs,DNS, VPNs, and VLAN.
This episode follows the modulefor the Compia core exam, and by
(01:35):
the end, you'll see how everypacket knows where it's going
and how it gets there.
Internet connection types frommobile from modems to fiber.
Every internet session beginswith a modem, the bridge between
your network and your internetservice provider.
DSL, digital subscriber line,runs over regular phone lines.
Asymmetric DSL is fasterdownload.
(01:57):
Symmetric DSLs keep speed equalsfor businesses that upload data
consistently.
Cable modems.
That's why upgrading to DOS Sys3.1 can bump you from 300
megabits per second to 1 gig.
Fiber to the premise.
(02:18):
Pure glass from the providerstraight to your home or
business, terminating at an ONT,optical network terminal.
Wireless and cellular.
Imagine a rural repair shop toofar for cable or fiber.
It might use a fixed wirelessthrough a wireless ISP or WISP.
Satellite, like the Starlink LEOLEO constellation, offer lower
(02:40):
latency alternative togeostationary orbit.
And on the go, cellular networkshave revolved from 3G CDM to 5G
with massive MIMO enablingspeeds once reserved for
wirelines.
Routers and firewalls.
Your router makes IP-basedforwarding decisions determining
which interface each packetuses.
(03:02):
Meanwhile, a firewall enforcesrules known as access
controllers.
Filtering traffic by IP, Mac,protocol, or port.
Think of it as a bouncerchecking IDs before anybody
enters the network club.
Here's an example.
A rule that says allow TCP 443from any internal web server
permits encrypted HTTPS trafficbut blocks everything else.
(03:29):
The four layer model.
The TCP IP is a suite ofprotocols with layers.
One, link layer, framestraveling using MAC address.
2.
Internet layer, routing packetsvia IP address.
3.
And 4.
The application layer protocolslike HTTP and DNS.
(03:52):
This TCPIP 4 layer model issimilar to the OSI model.
The OSI model, as you know, hasseven layers.
The TCPIP model has only fourlayers.
Each layer wraps the data in itsown header, like stacking
envelopes inside envelopes.
IPv4 masking and addressing.
(04:12):
An IPv4 address is 32 bits long.
Four octaves, eight bytes each.
Four times eight equals 32.
So for example, 192.168.1.25.
Each octave, so for example, 192will be considered an octave,
has eight bits.
168 has eight bits.
(04:33):
One has eight bits.
What do you get the number from?
The number, and I'll have to doa deep dive, a little bit of a
deep dive on this.
The number depends on how manybits you turned on.
Which bits you turn on.
So there's certain bits, youknow, there's eight, the eight
bits are 128.68, 32, 16, 842.1.
And so 25, you would have 16 on,8 on, and 1 on.
(04:58):
So that's the example.
But I'll do a little bit of adeep dive on another episode
about IP addressing.
It cannot be done.
It has to be its own separatetopic.
Uh the setnet mask devicenetwork ID and host ID.
Example 255.255.255.0 means thefirst three octaves identify the
network.
(05:18):
Public versus private.
Private range uses inside lens.
Use the class A is 10.0.0.0.
For class B, the range is172.16.0.0 to 172.31.255.255.
(05:38):
For class C is 192.192.168.0.0.
The router performs NAT ornetwork address translation,
mapping private address topublic ones.
That's a hundredths of device,share one internet IP.
Again, this is another topicthat's going to have its own
segment because it's just too,you know, I can do 23 minutes
(06:03):
just on public-privateaddressing.
So that'll be its own separatething.
So example, your phone192.168.1.50 says request.
The router translates it to7575.32.18.7 on the internet.
Uh the reply returns and is DNATback to you.
(06:25):
Static, dynamic, and uh PIPA.
Static IP, you manually enterit, useful for printers and
servers.
Usually you want to use staticIP for uh devices that are never
going to change, that you don'twant the IP never to change.
So you know, your printers, yourservers, your routers, maybe a
managed switch, right?
(06:46):
Those are devices that you neverwant to change.
So it's fine.
Uh DHCP automates addressassignments through Dora.
Discover, offer, request,acknowledge.
These are for like yourworkstations, right?
Things that you don't care ifthe IP address changes.
You know, pretty much yourworkstations, you don't really
care if the IP changes.
(07:07):
There's no you don't need tohard code your workstations.
And a PIPA is when the addressstarts with 169.254, appears
when DHCP fails, Windows way tostay local when disconnected.
IPv6, which is going to be thenew standard of internet
(07:30):
addressing, when is that gonnahappen?
Who knows?
I've been hearing about IPv6 forthe last 10 to 15 years.
Yeah, I don't know when it'scoming.
Coming soon, it's like forever.
So, what's the biggest obstacle?
I'm pretty I'm pretty sure it'smoney.
And why?
You know, why at this point, ifeverything's working, why change
(07:53):
it?
And then in order to change it,you know, it's gonna cost it's
gonna cost money, it's gonnacost time.
You gotta get these texts tomake all these changes.
That's that's gonna cost money.
But anyway, IPv6 uses 128 bits,hexadecimal notation, and
colons.
So an IP address can be let'ssay 2001 0 dB858300, colon 8A2E,
(08:27):
0370, 7334.
Dual stacking lets Ipv4 and IPv6run side by side.
Organizations adopt IPv6 for itsnearly limited address space.
I don't know anyone that isactually using it, but again,
it's coming soon.
(08:48):
You have your protocols andports.
TCP and UDP uses ports from zeroto sixty five thousand three
hundred to differentiateservice.
TCP is connection-oriented,which is reliable.
UDP is connectionless, faster,but no guarantees.
UDP is like Netflix, YouTube,right?
A lot of data going back, youknow, send me the data, send me
(09:09):
the data, send me the data,right?
TCP is like email, logging intoa website, right?
So some well-known ports that wehave out there that you know you
may need to learn.
FTP file transfer port codesuses port 2021 and is TCP based.
SSH, port number 22, TCP based,DNS 53, it's UDP and TCP based.
(09:35):
HTTP is 80 port, uh port 80 andit's TCP based.
HTTPS uh port numbers 443 andit's TCP based, DHCP, port
numbers 67 and 68, and it's UDPbased.
And RDP remote desktop is 3389TCP-based.
(09:57):
When you're visiting a websiteusing HTTPS, your browser
initiates a three-way handshake: sync, sync act, and act to (10:01):
undefined
establish a reliable connection.
Sync means synchronization andact means acknowledgement.
So it's synchronization,synchronization,
acknowledgement, and thenacknowledgement.
A real world example is a gamestreaming platform may use UDP
for real-time videos becausedropping a few frames is better
(10:23):
than delaying the stream.
Just like Netflix, right?
Dropping a few flame uh framesin Netflix is better than
delaying the film.
So and they use UDP.
Network configuration concepts,DHCP functions.
A DHCP server manages scope,leases, and reservations.
(10:44):
If you reserve a MAC address,that device always gets the same
IP.
Perfect for printers or securitycameras.
DNS, the phone book of theinternet.
The domain name systemtranslates names into IPs.
When you type, you know,www.google.com, right?
It resolves to something like8.8.8.8.
(11:07):
A record type should know Athrough quadruple A is IPv4,
IPv6, C name is your alias, MXis always for mail server, and
that's a clue for the Camtiatest, right?
If you see a question and thequestion that they ask you has
the word MX in it, just look formail server or email.
(11:29):
It's usually that's usually whatthe answer is.
And TXT or text uh verificationor SPF data.
Example DNS lookup follows achain root server, right?
Then the top level domain, andthen the authoritative server,
and then your answer VLANs andVPNs.
(11:51):
VLAN or virtual LAN segment aswitch into isolated uh
broadcast domains.
For instance, separating financetraffic from students in a
capitalist network, and thenyour virtual private network
creates an encrypted tunnel overpublic Wi-Fi.
Example, when you connect yourcollege VPN, all traffic to
internal servers is secure, evenif you're in a coffee shop.
(12:12):
Again, this some of this stuffwe would have to expand on it.
It's just you know, to do theseshort snippets that I'm trying
to do, especially with thequestions at the end and the
allotted 23 minutes, 24 minutetime that I want to get to.
It only gives us time for thesesnippets.
But I will do like a deep, deepdive into DHCP, DNS, VLANs.
(12:37):
I'm you know, that needs thatdeserves you know, a
public-private address, all thatstuff deserves huge deep dives,
separate podcasts on its own,separate episodes.
I'm following the the like whatCertmaster gives you, which
honestly doesn't really give youa lot as far as the PowerPoints
(12:58):
is concerned, and that's whatI'm using just to just for quick
snippets.
But to be fair, I have to, ifI'm gonna, you know, be a good
instructor or a good teacher, Ihave to give you the full
definition of what DHCP does.
And I have a whole thing, I youknow, if my if you take my class
(13:19):
and I've gone over DHCP, youknow how I do it.
I do a whole scenario and stuff,and but it deserves its own
episode.
You know, a couple of thesethings, now that we're getting
into the meat of A plus, itdeserves its own, its own uh
(13:59):
episode.
Some of these stuff is just toobig to cover in snippets.
So all right, let's do thequestions.
All right, so if you're new tothis, the way I do it is I ask
the question, I read thechoices, and then I do it again.
I give you five seconds and youtry to guess if the answer is
right.
(14:19):
Question one Which internetconnection typically uses an
optical network terminal at thecustomer's presence?
A DSL, B, cable, C fiber to thepremise, or D satellite.
Again, which quet which internetconnection type typically uses
the optical network terminal atthe customer premise?
A D DSL B cable C fiber to thepremise or D satellite.
(14:43):
I'll give you five seconds tothink about it.
Five, four, three, two, one.
And the answer is C, of course,fiber to the premise.
Connections terminate at an ONTthat converts optical signals
into internet for use inside thebuilding.
And ironically enough, ladiesand gentlemen, if you took my
(15:04):
classes years back, I wouldalways say there was, you know,
there's no way they would putfiber in your house.
But now they do.
They actually do put fiber inyour house, which I find amazing
that they do that because fiber,if you know anything about
fiber, it's very, very delicate.
I have a Verizon 2G, and there'sactually a fit of uh fiber cable
(15:28):
inside my house, which I neverthought they would do.
I would never throw they woulddo, but it's there, so I just
gotta be careful not to uh breakit.
All right, question twoaddressing.
Which IPv4 address range isreserved for automatic private
IP addressing or a PIPA?
A 10.0.0.0 slash eight, b169.254.0.0 slash 16, C
(15:56):
172.16.0.0 slash 12 or D what192.168.0.0 slash 16.
I'll read it again.
Which IPv4 address range isreserved for automatic private
IP addressing or a PIPA.
A 10.0.0.0 slash eight b169.254.0.0 slash 16 C
(16:24):
172.16.0.0 slash 12 or D192.168.0.0 slash 16.
I give you five seconds to thinkabout it.
54321 and the answer is B169.254.0.0 slash 16.
(16:46):
Windows assigns a PPR address inthe 169.254.0.0 to
169.254.255255 range when noDHCP server is available.
See, this is what I mean.
Like that is something that Ineed to explain more.
Right?
So maybe the next episode of A,I will go into a whole deep dive
(17:11):
of what DHCP is, how it works,you know, fully, fully express
explain it, break it down.
I think I do a really good jobof breaking it down for my
students for DHCP, you know,using a scenario that
everybody's familiar with.
And then that way they, youknow, you can they you really
understand how you know thingswork, right?
(17:33):
Because we're getting into thegranular level of things, and
you really need to know howthese things work, especially if
you're gonna take the A plusclass.
So, and I'm gonna do a lot moredeep dives on the on the A plus.
All right, protocols and ports.
A network administrator wants tosecure remote logins by encrypt
by encrypting traffic.
(17:55):
Which protocol and port shouldthey use?
A telnet port number 23, B SSH,port number 22, C HTTP, port
number 80, D FTP port number 21.
Again, I'll read it again.
A network administrator wants tosecure remote logins by
encrypting traffic.
Which protocols and ports shouldthey use?
(18:16):
A telnet slash 23 or port number23, SSH port number 22, HTTP
port number 80, or D FTP portnumber 21.
So this is uh here's how youwould tackle this question, and
this is part of the CAMTIA way,right?
If you look at the question, ifyou listen to the question,
(18:37):
because you can't look at it, ifyou listen to the question, you
will see that it says a networkadministrator wants to secure
just that word secure, that'sthe clue in the question,
secure.
So out of all of these, whichone could you eliminate right
away?
Well, HCTP is not secure, sothat's our right telnet.
(18:58):
If you know anything abouttelnet, that's not secure.
That's out, right?
And then you're left with SSHand FTP, and then wants to
secure remote logins.
The answer is B, SSH.
Right?
SSH encrypts remote terminalsessions, unlike telnet, which
sends data in plain text.
(19:19):
So there's also like a about, Idon't know, 20, 22 of these
ports that you need to know forthe exam.
I will also do a deep dive onthat.
It's important that you knowthese, and once you know them,
it scaffolds, right?
So this is the good thing aboutCompTIA, and this is the good
thing about taking a CompTIAexam at A plus, at the A plus
(19:42):
level, and not skipping toSecurity Plus like right away,
right?
There's some people who whoright away they don't they don't
do anything, they don't theydon't never worked in in PC
before.
Maybe they fixed their friend'sPC, right?
They're that one guy, butthey've never really, really
worked in IT.
So they want to jump all the wayto security, and the and that
(20:02):
that test is really hard.
I mean, there's people who'vedone it, and I've known two
people who have done it.
But both former students, butmost people can't.
I mean, you really, really,really gotta be dedicated if you
want to take a security pluscourse or study on your own.
I know one young lady whostudied on her own and she
(20:25):
passed, and then one took aclass with me and he passed.
But it's not it's not an easyexam, and to just try to jump in
the line is kind of difficult.
But if you start at A1, uh A, itscaffolds.
So you go to network plus, like50% of network plus is in A, and
like 30% of security plus isn'tA.
You know, you know, so you knowyou learn the foundation, and
(20:47):
it's better to start at A.
I don't know why people want tojump the line, but that you
know, that's them.
All right, last question: network configuration. (20:55):
undefined
What is the primary purpose ofvirtual LAN or VLAN on a managed
switch?
A to provide wireless coveragein large area, b to segment
network traffic for performanceand security, C to encrypt
tunnels over the internet, or Dto assign dynamic IP address to
(21:16):
clients.
I'll read it again.
What is the primary purpose of avirtual LAN or VLAN on a managed
switch?
A to provide wireless coveragein large areas, b to segment
network traffic for performanceand security, C to create
encrypted tunnels over theinternet, or D to assign dynamic
(21:37):
IP address to clients.
Now, you have a before youtackle this question, if you
listen to it, there's a coupleof clues here.
One is manage switch, right?
So anything that has to do withIP addresses, it's out because
switch does not manage IPaddress.
So D is out to assign dynamic IPaddress to clients, that's out,
(22:01):
right?
So you left with to providewireless coverage in large areas
to segment network traffic tofor performance and security and
to encrypt network tunnels overthe internet.
Nothing to do with the internet,a switch does not do anything
with the internet, C is out.
So you're left with A and B, andthe answer is B.
VLANs divide a switch intomultiple logical networks,
(22:22):
isolating traffic and reducingbroadcast domain for better
performance and security.
That's how you tackle A plusexam.
Just like the way I did it.
Just look at the question.
Not every question is going tohave a clue because a lot of
them is gonna say, hey, what'sthe port number for Telnet?
Right?
So that there's no clue in that.
(22:44):
Either you know it or you don'tknow it.
But some have clues.
And you look at the clues fromjust reading the clue, reading
the question, you gotta dissectit, right?
That's what I call it.
You gotta dissect the question.
And but you only got a minute todo it.
You don't have a lot of time,you gotta like average like a
minute of question.
(23:04):
So I always tell my students, gothrough the exam first, the
first time, answer the questionsthat you can answer, right?
If you answer the questions thatyou think you can get it right,
answer those and then go backand then answer the rest, and
then take your time because youcan answer a question that you
know like 10-15 seconds.
So then that you know that willhelp you 100%.
(23:28):
Alright, let's wrap this up,guys.
From DSL to DNS, from IPv6 toVPNs, you now understand how
iDressing keeps the internetorganized.
That Comp Tia test doesn't justtest your memory, it tests how
you think through connectivityproblems.
(23:49):
I'm Professor J.
Rod, and I just want to remindyou stay curious, stay secure,
and always keep tapping intotechnology.
(24:34):
This has been a presentation ofLittle Cha Cha Productions, art
by Sarah, music by Joe Kim.
We're now part of the Pod MatchNetwork.
You can follow me at TikTok atProfessorJrod at J R O D.
Or you can email me atprofessorjrodjr-od at gmail.com.
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