Speaker 1: Okay, let's unpack this. In a world that feels well
Speaker 1: increasingly connected, have you ever stoked to think about the
Speaker 1: invisible architecture that actually makes it all possible?
Speaker 2: It's everywhere, isn't it?
Speaker 1: Right, From the simplest text message to complex cloud services,
Speaker 1: there's this intricate dance happening just beneath the surface, a
Speaker 1: huge digital highway moving data.
Speaker 2: Everywhere, absolutely a constant flow.
Speaker 1: Today we're taking a deep dive into the very backbone
Speaker 1: of our digital lives network technologies. We're going to try
Speaker 1: and demystify some foundational concepts, explore crucial protocols.
Speaker 2: And even peek into the future a bit with automation exactly.
Speaker 1: And our guides for this journey, well, we're drawing from
Speaker 1: an incredibly comprehensive set of sources, basically expert level stuff
Speaker 1: distilled into digestible insights.
Speaker 2: Yeah, breaking down the complex bits.
Speaker 1: Our mission really is to give you a shortcut to
Speaker 1: being truly well informed about how networks function, hopefully revealing
Speaker 1: some surprising facts, practical.
Speaker 2: Insights, things that might change how you see your connected world.
Speaker 1: Yeah, charity for some serious aha moments. Hopefully, let's do it.
Speaker 1: So to kick things off on our digital highway. We
Speaker 1: need to understand its basic structure. Think of it like
Speaker 1: building a complex building, maybe layer by layer, each floor
Speaker 1: with its own job.
Speaker 2: That's a good analogy. The OSI model is that blueprint. Essentially,
Speaker 2: it helps us grasp how information travels across a network,
Speaker 2: piece by.
Speaker 1: Piece, layer by invisible layer. Right.
Speaker 2: And it's remarkable how this layered approach breaks down immense complexity.
Speaker 2: If we start near the bottom at layer two, the
Speaker 2: data link layer, okay, you're in the immediate vicinity, like
Speaker 2: the local street in our digital neighborhood. This is where
Speaker 2: MBACK addresses are key.
Speaker 1: Ah. The MSSE addresses, those unique hardware identify.
Speaker 2: Exactly, those unique physical identifiers for devices. They're absolutely essential
Speaker 2: for communication within the same local network.
Speaker 1: So my laptop is talking to my printer right here,
Speaker 1: or my phone's hitting the Wi Fi. That's m ASSE
Speaker 1: addresses doing the work locally precisely.
Speaker 2: And the key devices here are switches. They're directing that
Speaker 2: local traffic based on those mass addresses. A switch basically
Speaker 2: keeps an address book a table for each separate segment,
Speaker 2: like different vlands if you have them, okay, and if
Speaker 2: it doesn't know where a specific m call address lives, Well,
Speaker 2: it'll temporarily send the data out to all connections in
Speaker 2: that segment.
Speaker 1: Sort of like shouting down the street anyone seeing this.
Speaker 2: Device kind of yeah, yeah, until it learns the correct path.
Speaker 2: And here's something that often surprises people. The Spanning Tree
Speaker 2: Protocol STP, or its faster cousin RSTP, operates right here
Speaker 2: at this very local layer two.
Speaker 1: Really at layer two. But isn't that the thing that
Speaker 1: stops networks from collapsing in on themselves with loops.
Speaker 2: It is. It's the unsung hero preventing those crippling network loops.
Speaker 2: You'd think it'd be higher up.
Speaker 1: Maybe. Yeah, that is surprising. It seems so fundamental. Okay,
Speaker 1: so if layer two is the local street, layer three,
Speaker 1: the network layer must be the GPS for the whole
Speaker 1: highway system.
Speaker 2: That's a great way to put it. This is where
Speaker 2: IP addresses come in. They enable communication between different networks.
Speaker 1: So from my home network to a website server halfway across.
Speaker 2: The world exactly. And writers are navigators here. They make
Speaker 2: the forwarding decisions to get data from network A to
Speaker 2: network B.
Speaker 1: Gotcha.
Speaker 2: And routers are truly crucial for segmenting networks. This helps
Speaker 2: control that broadcast traffic we mentioned, stops the shouting from
Speaker 2: echoing across the whole city, you know, right, keeps it local,
Speaker 2: keeps it local. And they also allow for really sophisticated
Speaker 2: filtering using access control lists ACLS.
Speaker 1: Okay, ACLS like a bouncer's.
Speaker 2: List sort of. Yeah, detailed rules saying exactly what traffic
Speaker 2: gets through, super important for security and just managing traffic
Speaker 2: flu efficiently.
Speaker 1: Okay, So we have these layers. Now let's move from
Speaker 1: that structure to how data actually gets well delivered. You
Speaker 1: mentioned TCP and UDP before the odd couple.
Speaker 2: Huh, yeah, the odd couple of data delivery. It really
Speaker 2: is a fundamental choice you have to make when sending information.
Speaker 2: Do you need absolute reliability or is speed the name
Speaker 2: of the game?
Speaker 1: Reliability versus speed?
Speaker 2: Okay, So TCP transmiss Control Protocol, that's your reliable messenger.
Speaker 2: It's connection oriented, meaning it sets up a formal conversation first.
Speaker 2: It uses something called a three way handshake Hello, Hello, okay,
Speaker 2: let's talk.
Speaker 1: Right, establishes the connection properly.
Speaker 2: Exactly, and this ensures data reliability. It guarantees delivery, provides
Speaker 2: flow control, so you don't overwhelm the receiver, and even
Speaker 2: includes error recovery. If packets get lost along the way,
Speaker 2: it'll ask for them again.
Speaker 1: So that sounds perfect For things like downloading a big
Speaker 1: file or browsing a website, where every single piece of
Speaker 1: data really matters. You can't have missing.
Speaker 2: Bits precisely, a corrupted file, a half loaded web page. Yeah,
Speaker 2: that's no good. Missing packets there would be well disastrous.
Speaker 1: Okay, makes sense. So what about the other one, UDP,
Speaker 1: the fast post.
Speaker 2: Card right, UDP User Datagram Protocol. It's the opposite in
Speaker 2: many ways. It's connectionless, so no handshake, no handshake, much
Speaker 2: lower overhead. It just sends the data, no guarantees it'll
Speaker 2: get there or in what order. That sounds risky it
Speaker 2: can be, But the application using it can build in
Speaker 2: its own checks like check sums if it needs to
Speaker 2: verify integrity. But the key is speed.
Speaker 1: Uh so where would that be useful? Where speed beats
Speaker 1: perfect reliability?
Speaker 2: Think about real time stuff like voiceover IP VoIP calls
Speaker 2: or video conferencing.
Speaker 1: Okay, yeah, like this call right now? Maybe exactly.
Speaker 2: If a few tiny bits of data get lost in
Speaker 2: a voice call, you might get a tiny glitch like
Speaker 2: a split second dropout.
Speaker 1: But the conversation keeps going, right.
Speaker 2: The alternative with TCP would be waiting for that lost
Speaker 2: packet to be resent, and that would cause noticeable delays
Speaker 2: and shoppiness, breaking the real time feel. UDP prioritizes keeping
Speaker 2: the flow going.
Speaker 1: That makes perfect sense. You accept tiny imperfections for the
Speaker 1: sake of immediacy.
Speaker 2: Okay, cool, It's all about the application's needs, right.
Speaker 1: So, speaking of IP addresses, which you mentioned for layer three,
Speaker 1: let's dive a bit deeper there. They're like our network
Speaker 1: identity but you said they're public and private ones.
Speaker 2: Correct. Think of private IP four addresses as the internal
Speaker 2: phone extensions within a large office building, or maybe addresses
Speaker 2: inside your internal clubhouse, your home network, a company's internal network.
Speaker 1: Okay, not visible from the outside world exactly.
Speaker 2: They're crucial for internal communication and importantly, they don't need
Speaker 2: to be globally unique. This was a really clever strategy
Speaker 2: early on. Why is that because it conserves the limited
Speaker 2: pool of public IPv four addresses. Plus devices on these
Speaker 2: private networks can chat amongst themselves without even needing an
Speaker 2: Internet connection.
Speaker 1: Ah, so my laptop talking to my smart speaker at
Speaker 1: home using those one undred and ninety two point one
Speaker 1: six eight addresses for example.
Speaker 2: Precisely those are from specific ranges defined in RFC nineteen eighteen,
Speaker 2: like ten taught something one seventy two point one six
Speaker 2: through one seventy two point three to one and one
Speaker 2: ninety two point one six eight taught something. They're non
Speaker 2: ratable on the public Internet.
Speaker 1: Clever way to save address space. But we are running
Speaker 1: out of IPv four addresses, right, That's where IPv six
Speaker 1: comes in.
Speaker 2: That's the big driver for IPv six. It's the next
Speaker 2: generation designed to solve that address exhaustion problem with a
Speaker 2: vastly larger address space, like unimaginably larger.
Speaker 1: Wow. And does I have different types of addresses too?
Speaker 2: It? Does you have global unicast addresses? Those are your
Speaker 2: publicly routable ones like public IPv four and unique local addresses.
Speaker 1: Like the private IPv.
Speaker 2: Four ones sort of yeah, similar idea for internal use,
Speaker 2: not globally routable. They start with FC zero zero point
Speaker 2: seven and then link local addresses starting with FE eighty
Speaker 2: point ten link local. Yeah. Those are only for communication
Speaker 2: on the immediate local network segment, like directly connected neighbors
Speaker 2: talking to each other automatically without needing any configuration.
Speaker 1: Huh. Interesting, And you mentioned something about tunneling IPv six
Speaker 1: over IPv four.
Speaker 2: Ah, yeah, six to four tunneling. It's a transition mechanism,
Speaker 2: a really smart way to bridge the gap, basically letting
Speaker 2: you route IPv six traffic over an existing itv four.
Speaker 1: In structure, so you don't have to upgrade everything everywhere,
Speaker 1: all at once.
Speaker 2: Exactly. It's like building an express lane for the new
Speaker 2: IPv six cars on the old ITV four highway smooths.
Speaker 2: The transition makes sense. And one more thing about IPv
Speaker 2: six when you enable it on an interface, the device
Speaker 2: automatically joins certain multicast groups like the All Nodes group
Speaker 2: and the All Routers group. Helps it discover things on
Speaker 2: the network.
Speaker 1: Okay, so it's designed to be a bit more plug
Speaker 1: and play in some ways.
Speaker 2: In some ways, yes, So we have all these addresses
Speaker 2: later two layer three, How do the routers the navigators
Speaker 2: actually make sense of this huge digital map and decide
Speaker 2: where to send stuff?
Speaker 1: Right? That's the network's core. How routers make decisions. They're
Speaker 1: constantly looking at their map, which we call a routing.
Speaker 2: Table, and what's in that table?
Speaker 1: It's got all sorts of vital info the destination network prefix,
Speaker 1: the mask, how to get there, the next hop router
Speaker 1: usually and some metrics about the path, maybe even a
Speaker 1: default route the gateway of last resort.
Speaker 2: Okay, but what happens if a router has, say two
Speaker 2: or three different ways to get to this same destination network.
Speaker 2: How does it choose?
Speaker 1: Ah? Good question. There's a very specific decision making hierarchy.
Speaker 1: It's not random.
Speaker 2: Okay, what's the order?
Speaker 1: First? The router prioritizes the longest prefix match.
Speaker 2: Longest match meaning the most specific.
Speaker 1: Route, exactly like choosing a route based on a full
Speaker 1: street address versus just the city name. More specific is better?
Speaker 2: Got it makes sense. What if there's a tie two
Speaker 2: routes with the same prefix length, then.
Speaker 1: It looks at something called administrative distance or AD.
Speaker 2: Administrative distance sounds official?
Speaker 1: It kind it is. It's basically a trust score that
Speaker 1: network admins assigned to routes learn from different riding protocols.
Speaker 2: AH. So it's about trusting one source of information over another.
Speaker 1: Precisely, a lower AD is preferred, it's considered more trustworthy.
Speaker 1: For example, a route learned via EIGRP usually has an
Speaker 1: ed of ninety while OSPF is UNDERD ten. So the
Speaker 1: router would generally prefer the EIGRP route if both protocols
Speaker 1: offered a path to the same place.
Speaker 2: Interesting, so longest my UCH first, then lowest AD. What
Speaker 2: if it's still a tie, same prefix, same AD.
Speaker 1: Then finally it looks at the routing protocol's own metric.
Speaker 1: That's the protocols calculation of the cost the path may
Speaker 1: be based on bandwidth delay things like that lower metric.
Speaker 2: Wins longest match AD than metric. Okay, that's a clear hierarchy.
Speaker 1: Yeah. It ensures predictable and optimal routing. And speaking of
Speaker 1: reliable routing, this all connects to making sure there's no
Speaker 1: single point of failure, right, especially for devices trying to
Speaker 1: leave their local network.
Speaker 2: Absolutely, you need redundancy for that default gateway. That's where
Speaker 2: first top redundancy protocols or fhrps come in. Things like HSRP,
Speaker 2: VRP GLBP.
Speaker 1: HSRP hot standby router protocol. That's a Cisco one, isn't it.
Speaker 2: It is, Yeah, Cisco proprietary. It uses an active standby model.
Speaker 2: Multiple routers share a virtual IP and a virtual MC address,
Speaker 2: but only one is actively forwarding traffic at.
Speaker 1: Any time, and the others just wait.
Speaker 2: They will wait, ready to take over instantly if the
Speaker 2: active one fails. There's often setting called preempt too. Preempt Yeah,
Speaker 2: it ensures that if the router with the highest priority
Speaker 2: comes back online after failing, it takes back the active
Speaker 2: role from a lower priority router that might have taken
Speaker 2: over temporarily.
Speaker 1: Ah. So it forces the best router to always be
Speaker 1: in charge when available exactly.
Speaker 2: This isn't just about basic availability. It's about ensuring high
Speaker 2: availability and eliminating that single point of failure that could
Speaker 2: stop everyone from reaching the Internet. For example, it makes
Speaker 2: fail over seamless.
Speaker 1: That is a huge benefit, makes a network much more resilient. Okay,
Speaker 1: so we've got the core routing down. Let's shift gears
Speaker 1: to building resilient and secure networks, starting with something we
Speaker 1: all use constantly wireless the Wi fi world.
Speaker 2: Ah. Yes, the airwaves, and one of the biggest headaches,
Speaker 2: especially in the older two point four gearhart span, is
Speaker 2: avoiding digital noise right interference.
Speaker 1: Yeah, like when your WiFi slows to a crawl because
Speaker 1: everyone nearby is using the same.
Speaker 2: Channel exactly, co channel congestion. The best practice, especially for
Speaker 2: two points for gigahertz is absolutely to use different non
Speaker 2: overlapping channels for nearby access points. Think channels one, six,
Speaker 2: and eleven.
Speaker 1: Right, those specific three don't interfere with each other.
Speaker 2: Correct. Spacing them out physically and using those channels drastically
Speaker 2: reduces interference and improves performance for everyone.
Speaker 1: Okay, simple but crucial. But what about larger places like
Speaker 1: an office building or a campus with tons of access points? Yeah,
Speaker 1: managing them individually sounds awful.
Speaker 2: It would be a nightmare. That's why we have wireless
Speaker 2: land controllers or wlc's. They act as a central brain
Speaker 2: for the wireless.
Speaker 1: Network, centralized command and control.
Speaker 2: Precisely, the WLC manages potentially hundreds or thousands of access points,
Speaker 2: pushing out configurations, handling, roaming, security, everything. It massively simplifies management.
Speaker 1: And they have smart features too.
Speaker 2: Oh yeah, things like band select or common. The WLC
Speaker 2: can actively encourage devices that support five gigaherts to connect
Speaker 2: to that band instead of the more crowded two point
Speaker 2: four gigaherds.
Speaker 1: Pushing clients to the faster, less congested lanes.
Speaker 2: Got it better performance. And there's also a cool feature
Speaker 2: called flex connect ap mode.
Speaker 1: Flex connection Yeah.
Speaker 2: Imagine an access point in a remote branch office connected
Speaker 2: back to a central WLC. If that connection to the
Speaker 2: WLC drops, a flex connect AP can actually keep serving
Speaker 2: its locally connected wireless clients, switching their traffic right onto
Speaker 2: the local wired network.
Speaker 1: Oh wow, so the local Wi Fi keeps working even
Speaker 1: if the main controller link is down. It's huge for resilience.
Speaker 2: It really is insure seamless connectivity locally. Now, speaking of wireless,
Speaker 2: security is obviously paramount. We've moved beyond wp thankfully hopefully.
Speaker 1: Yeah. So WPA two using PSK, the pre shared key,
Speaker 1: the strongest encryption there.
Speaker 2: For WPA two PSK you definitely want to be using
Speaker 2: as encryption. That's the standard. But the real enhancement now
Speaker 2: is WPA three.
Speaker 1: WPA three, what's the big deal there?
Speaker 2: It significantly steps up security. It uses something called SAE
Speaker 2: Simultaneous authentication.
Speaker 1: Of equals EA ease.
Speaker 2: Yeah, it provides much stronger protection against offline dictionary attacks
Speaker 2: people trying to guess your Wi Fi password, and it
Speaker 2: also provides individualized data encryption even on open networks.
Speaker 1: So safer connections, especially on public Wi Fi.
Speaker 2: Much safer. It's a big leap forward and wireless security
Speaker 2: is just one piece of the puzzle. Right, we need
Speaker 2: to think about guarding the gates across the entire network.
Speaker 1: Absolutely, network security essentials. Where do we start? Maybe with
Speaker 1: who's allowed on the network in the first place.
Speaker 2: That's the perfect starting point. Triple A, Authentication, authorization.
Speaker 1: And accounting the three pillars.
Speaker 2: The three pillars. Indeed, authentication is about verifying who you are,
Speaker 2: use your name, password, maybe.
Speaker 1: MFA okay, proving identity.
Speaker 2: Authorization is about what you're allowed to do once you're authenticated,
Speaker 2: Which resources can you access, what commands can you run?
Speaker 2: Defining permissions and accounting is about tracking what you did logging,
Speaker 2: access commands, run resources used crucial for auditing and troubleshooting.
Speaker 1: Got it often off ze AP, and.
Speaker 2: There are protocols for this, like Radius and TACAX plus ACT.
Speaker 2: A key difference people should know is that tac ass
Speaker 2: plus ACT, which is often used for device administration, separates
Speaker 2: the authentication and authorization.
Speaker 1: Steps, unlike Radius right.
Speaker 2: Radius tends to combine them. That separation in TACAX plus
Speaker 2: allows for much more granular control over exactly what authenticated
Speaker 2: users are authorized to do.
Speaker 1: Interesting distinction, okay, beyond user access what's the main network
Speaker 1: gatekeeper the firewall?
Speaker 2: The firewall absolutely think of it as the network's bouncer,
Speaker 2: standing at the main.
Speaker 1: Door, controlling what gets in.
Speaker 2: And out exactly. Its primary role is controlling which packets
Speaker 2: can cross between different security zones, typically between an untrusted
Speaker 2: network like the Internet and your trusted internal network.
Speaker 1: And modern firewalls are pretty smart about it, right. They
Speaker 1: don't just look at addresses.
Speaker 2: Not at all. They perform stateful inspection. They keep track
Speaker 2: of active connection stateful.
Speaker 1: Meaning they understand the context of the traffic. If you
Speaker 1: initiated a connection outward words to a website, the firewall
Speaker 1: knows to expect the return traffic for that specific conversation
Speaker 1: and allows it back in. It's not just looking at
Speaker 1: individual packets in isolation.
Speaker 2: Ah, like the bouncer remembering who went out for a
Speaker 2: smoke break and letting them.
Speaker 1: Back in exactly like that. It makes decisions based on
Speaker 1: the state of the conversation. Much more secure than older
Speaker 1: stateless firewalls.
Speaker 2: Okay, firewalls are critical, but what about security inside the
Speaker 2: local network on the switches themselves. Layer two security.
Speaker 1: Very important area often overlooked. There are several key features
Speaker 1: switches can implement. One is DHCP.
Speaker 2: Snooping DHCP snooping with that snooping on.
Speaker 1: It's watching the DHCP conversation the processed devices used to
Speaker 1: get an IP address automatically. It filters out malicious or
Speaker 1: abnormal DHCP messages like someone trying to set up a
Speaker 1: robe DHCP server to hijack traffic. It builds a table
Speaker 1: of legitimate IP to MBAG address.
Speaker 2: Bindings okay, prevents DHCP shenanigans.
Speaker 1: What else Dynamic ARP inspection or DAI. This uses the
Speaker 1: information gathered by DHCP snooping ARP.
Speaker 2: The address resolution protocol maps IPS to max. DAI checks
Speaker 2: ARP packets against that trusted DHCP snooping binding table. If
Speaker 2: an ARP packet comes in claiming an IP belongs to
Speaker 2: a MAC address that doesn't match the table, DAI drops it.
Speaker 1: Ah. So it stops attackers from pretending to be the
Speaker 1: gateway or another device man in the middle attacks exactly.
Speaker 2: It significantly reduces the risk of those specific layer two attacks.
Speaker 2: And then there's port security.
Speaker 1: Port security sounds straightforward, securing the switch port pretty much.
Speaker 2: It lets you limit the number of ASSE addresses allowed
Speaker 2: to connect to a specific switchport. You could say only
Speaker 2: a lie one device on this port or maybe allowed to,
Speaker 2: or even specify the exact APCI addresses allowed and.
Speaker 1: What happens if someone violates that plugs in an extra device.
Speaker 2: You can configure different violation modes. Shut Down just disables
Speaker 2: a port, restrict drops the violating traffic, but keeps the
Speaker 2: port up and sends an alert maybe a SNMP trap
Speaker 2: notification and increment's accounter.
Speaker 1: So you have options on how strictly to enforce it.
Speaker 2: Right and a basic but crucial step for unused ports
Speaker 2: to shut them down administratively and maybe assign them to
Speaker 2: an unused villain. Don't leave open doors.
Speaker 1: Good practice, yeah, simple but effective. Now circling back to
Speaker 1: users for a moment. Passwords alone aren't enough anymore, are they.
Speaker 1: Multi factor authentication MFA absolutely critical.
Speaker 2: MFA is huge. It requires more than one type of
Speaker 2: credential light something you know, password is something you have
Speaker 2: like a phone app notification, a hardwor token, or something
Speaker 2: you are biometrics like fingerprint. Using at least two of
Speaker 2: those drastically increases security, because.
Speaker 1: Even if someone steals your password.
Speaker 2: They still can't log in without that second factor, like
Speaker 2: the code from your phone. It massively reduces the risk
Speaker 2: of account compromise. It's becoming standard practice for a reason.
Speaker 1: Definitely seems worth a slight extra effort and one more
Speaker 1: security piece. VPNs for secure connections.
Speaker 2: Yes, virtual private networks essential for secure remote access or
Speaker 2: connecting different office sites securely over an untrusted network like
Speaker 2: the Internet.
Speaker 1: How do they work? Basically, they create.
Speaker 2: A secure encrypted tunnel. All the data traveling between your
Speaker 2: device or office and the VPN endpoint on the other
Speaker 2: side is.
Speaker 1: Encrypted, so even if someone intercepts the traffic on the public.
Speaker 2: Internet, they just see scrambled data. VPNs protect both the privacy,
Speaker 2: confidentiality and the integrity. Making sure data isn't tampered with
Speaker 2: of your connection super important.
Speaker 1: Okay, so we've locked things down, Now, how do we
Speaker 1: make sure the important stuff gets through smoothly? Quality of
Speaker 1: service QoS?
Speaker 2: Right, with all this data flowing, not all traffic is
Speaker 2: created equal, is it. A video conference is much more
Speaker 2: sensitive to delays than an email download.
Speaker 1: True email can wait a few seconds. A shoppy video
Speaker 1: call is painful exactly.
Speaker 2: QoS is all about managing network resources to give preferred
Speaker 2: treatment to certain types of traffic. We need to look
Speaker 2: at a few key metrics delay, how long it takes
Speaker 2: packets to get across jitter, the variation in that delay.
Speaker 2: Consistent delay is often okay, but rapidly changing delay makes
Speaker 2: voice and video sound terrible, and loss packets that just disappear.
Speaker 1: Delay, jitter, loss the enemies of real time communication pretty much.
Speaker 2: So QoS uses various mechanisms to combat these.
Speaker 1: What kind of mechanisms, Well, first.
Speaker 2: You need classification, identifying what kind of traffic it is, voice, video,
Speaker 2: bulk data, et cetera. Then marking, tagging the packets with
Speaker 2: a priority level. You might see terms like DSP or
Speaker 2: class of service COS.
Speaker 1: Okay, identify and tag.
Speaker 2: Then what Then you use tools like queueing, holding packets
Speaker 2: and different prioritize memory buffers on the router or switch,
Speaker 2: and maybe shaping, smoothing out bursts of traffic by buffering
Speaker 2: and slightly delaying packets to meet a target rate or
Speaker 2: policing which is stricter just dropping packets that exceed a
Speaker 2: certain rate limit.
Speaker 1: So sorting, tagging, buffering, maybe slowing down or dropping less
Speaker 1: in stuff.
Speaker 2: That's the gist. And one really critical queuing technique, especially
Speaker 2: for voice and video, is called low latency queuing or
Speaker 2: LQ sometimes called a priority.
Speaker 1: Queue low latency queuing. What does that do?
Speaker 2: It basically creates an express lane. Packets marked as high
Speaker 2: priority like voice get put in this queue, and the
Speaker 2: router always services this queue first before handling packets and
Speaker 2: other lower priority queues.
Speaker 1: Ah, so the voice packets jump the line every time exactly.
Speaker 2: This dramatically reduces delay and jitter for that specific traffic,
Speaker 2: ensuring your calls and video conferences stay clear even when
Speaker 2: the network is busy with other things. It's a game
Speaker 2: changer for real time apps.
Speaker 1: Makes sense, And I guess you can apply different levels
Speaker 1: like gold, Silver, bronze service.
Speaker 2: Yeah, you often see QoS profiles like that, especially in
Speaker 2: wireless environments. Maybe platinum for voice, gold for video, Silver
Speaker 2: for business apps, Bronze for best effort.
Speaker 1: Cool. Okay, that covers optimizing the current flow. Now the
Speaker 1: future you mentioned earlier, automation and programmability. This feels like
Speaker 1: a big shift.
Speaker 2: It absolutely is a fundamental shift in how networks are managed.
Speaker 2: We're moving away from the old ways.
Speaker 1: What was the old way? Traditional networks?
Speaker 2: Traditional networks generally have a distributed architecture. Each router, each
Speaker 2: switch has its own brain, its control plane, making its
Speaker 2: own independent routing and forwarding decisions based on the protocols
Speaker 2: it's running.
Speaker 1: So lots of individual brains coordinating right.
Speaker 2: And while that's robust, managing it at scale becomes incredibly complex.
Speaker 2: Making changes across hundreds or thousands of devices manually is slow,
Speaker 2: error prone, just difficult.
Speaker 1: I can imagine. So what's the new approach? Controller based SDN.
Speaker 2: Exactly, controller based networking or software defined networking SDN. This
Speaker 2: is like giving the network a central brain.
Speaker 1: A single point of intelligence.
Speaker 2: Well, the control plane functions, the thinking part, are centralized
Speaker 2: onto a software controller or a cluster of controllers for redundancy.
Speaker 2: The actual muscles, the data plane forwards traffic remain distributed
Speaker 2: on the switches and routers, but.
Speaker 1: They take instructions from this central controller.
Speaker 2: Precisely, the controller tells the network devices how to handle
Speaker 2: traffic flows. This separation of the control plane brain and
Speaker 2: data plane muscles is the defining characteristic of SDM.
Speaker 1: And why is that better? What are the benefits?
Speaker 2: Huge benefits. You get centralized management and visibility. You can
Speaker 2: see and control the entire network from one place. Configuration
Speaker 2: complexity drops dramatically, and deploying news services or making network
Speaker 2: wide changes becomes much faster. Think tools like Cisco DNA
Speaker 2: Center embody this approach, so.
Speaker 1: Faster, simpler management, more agility.
Speaker 2: Definitely, it enables network automation in ways that just weren't
Speaker 2: feasible before. It really changes the game for network operations.
Speaker 1: Okay, But for this central controller to talk to all
Speaker 1: the network devices and for applications to talk to the controller, yeah,
Speaker 1: they need a common language, right. That's where APIs come in.
Speaker 2: Exactly. API's Application programming interfaces are absolutely fundamental to SDN
Speaker 2: and network automation.
Speaker 1: What is an API?
Speaker 2: In simple terms, think of it as a contract or
Speaker 2: maybe a menu. It defines exactly how different software components
Speaker 2: should interact, what requests one can make, what data it
Speaker 2: expects back, the format of that data. It's a standardized
Speaker 2: way for software to talk to other software.
Speaker 1: Okay, communication contract. And you mentioned northbound and southbound APIs, right, That.
Speaker 2: Describes the direction relative to the SDN controller. Northbound APIs
Speaker 2: are used by applications above the controller, maybe a monitoring dashboard,
Speaker 2: an automation script, or a business application. They use these
Speaker 2: APIs to ask the controller for network information or to
Speaker 2: program network behavior.
Speaker 1: So apps talking down to the controller.
Speaker 2: YEP and southbound APIs are used by the controller to
Speaker 2: talk down to the actual network hardware, the switches and routers.
Speaker 2: These APIs allow the controller to push configurations, install forwarding rules,
Speaker 2: and get status updates from the devices. Examples include protocols
Speaker 2: like OpenFlow or net confine.
Speaker 1: Got it northbound for apps, southbound for hardware? And are
Speaker 1: there specific types of APIs that are common now? I
Speaker 1: hear about REST APIs a lot.
Speaker 2: Rest APIs are incredibly popular. Yes. REST stands for representational
Speaker 2: state transfer. It's an architectural style that uses standard web protocols,
Speaker 2: specifically HTTP verbs.
Speaker 1: HTTP verbs like get, post, put delete used in web.
Speaker 2: Browsing exactly those They map nicely to the basic operations
Speaker 2: you want to perform on data or resources, often called
Speaker 2: the cr remodel create, read, update, delete, So a get
Speaker 2: request reads information, a post create something new, put updates it,
Speaker 2: delete removes it.
Speaker 1: So using familiar web technology to interact with network systems.
Speaker 2: That's a big part of why REST became so popular.
Speaker 2: It's relatively simple, stateless and uses technologies developers already understand,
Speaker 2: and the data exchanged often in formats like JSON or XML.
Speaker 2: Jason JavaScript object notation right Jason is particularly popular because
Speaker 2: it's lightweight and very human readable. It uses simple structures
Speaker 2: like objects, which are just collections of attribute value pairs
Speaker 2: like a dictionary, and arrays, which are ordered.
Speaker 1: Lists, easier to work with than older formats.
Speaker 2: Maybe generally, yes, it's readability and the widespread support in
Speaker 2: programming languages really helped accelerate the adoption of network automation
Speaker 2: and programmability through APIs. It just made things much more accessible.
Speaker 1: Okay, so APIs let us talk to the network programmatically?
Speaker 1: Does that lead to managing configurations differently too? Like code
Speaker 1: not clicks.
Speaker 2: That's the mantra infrastructure as code or network as code.
Speaker 2: Instead of manually logging into devices via command line or
Speaker 2: using graphical interfaces to click through settings.
Speaker 1: Which is slow and prone to typos.
Speaker 2: Exactly, we use configuration management tools. You've probably heard names
Speaker 2: like puppet, Chef, antsable, salt stack right.
Speaker 1: Answable seems particularly popular and networking lately. It is.
Speaker 2: One reason is that antsable is typically agentless. Agentless meaning
Speaker 2: you don't usually need to install special client software on
Speaker 2: the network devices you want to manage. It typically communicates
Speaker 2: using standard protocols like SSH, which most network devices already.
Speaker 1: Support AH lower barriered entry right.
Speaker 2: And it uses a push model. The ansible control node
Speaker 2: pushes configurations out to the managed devices. The instructions are
Speaker 2: defined in files.
Speaker 1: Called playbooks flybooks, what are they like?
Speaker 2: They're usually written in YAMEL, which is another human readable
Speaker 2: data format. Playbooks define the desired state of the devices,
Speaker 2: what configuration should be present, what services should be running.
Speaker 2: Antsible then figures out how to make the device match
Speaker 2: that state.
Speaker 1: So you define the end result you want, not necessarily
Speaker 1: every single command to get there.
Speaker 2: That's the idea declarative contiguration. This allows for incredibly consistent
Speaker 2: and repeatable setups across potentially thousands of devices. You run
Speaker 2: the same playbook, you get the same result every time.
Speaker 1: That must drastically reduce human.
Speaker 2: Error immensely, and it speeds up deployment massively. Combine these
Speaker 2: tools with version control systems like get, where you track
Speaker 2: changes to your playbooks just like software code, and you
Speaker 2: have a really powerful, auditible and automated way to manage
Speaker 2: network infrastructure. It's truly transforming the field.
Speaker 1: Wow, that's a huge leap from manual configs. Okay, so
Speaker 1: we've covered a lot of ground here.
Speaker 2: We certainly have from the basic layers up to cutting
Speaker 2: edge automation.
Speaker 1: So what does this all mean. We've journeyed from those
Speaker 1: foundational layers of network communication, understanding how data actually travels.
Speaker 2: Through the intricate decisions routers make using things like longest
Speaker 2: match and administrative distance.
Speaker 1: All the way to securing our digital boundaries with firewalls,
Speaker 1: triple A, MFA VPNs, and then optimizing flow with QoS.
Speaker 2: And finally landing on the future this shift towards centralized
Speaker 2: control with SDN, the power of APIs, and managing networks
Speaker 2: as code with automation tools.
Speaker 1: Yeah, and these aren't just like abstract technical details, are
Speaker 1: they not?
Speaker 2: At all? These are the principles the mechanisms that literally
Speaker 2: underpin our entire interconnected world.
Speaker 1: Everything from a simple text message or video call to
Speaker 1: global finance, cloud computing, everything relies on this stuff working.
Speaker 2: Understanding these concepts, even at a high level is genuinely
Speaker 2: a shortcut to being well informed in our digital age.
Speaker 2: It demystifies so much of the technology we use every
Speaker 2: single day.
Speaker 1: Absolutely so maybe a final thought to leave people with
Speaker 1: As networks become increasingly intelligent, more automated, maybe even self
Speaker 1: managing through AI down the line. How do you think
Speaker 1: this fundamental shift will impact our daily lives?
Speaker 2: That's the big question, isn't it.
Speaker 1: Yeah? And what about the roles we play in building
Speaker 1: and maintaining these systems, What new capabilities might emerge that
Speaker 1: we can barely even imagine today, And maybe most importantly
Speaker 1: for you listening, how will you continue to adapt and
Speaker 1: expand your own understanding of this constantly evolving digital landscape?
Speaker 2: Food for thought. Definitely, the pace of change isn't slowing down.