Multicast Explained in 5 Minutes | CCIE Journey for Week 6-12-2020
Summary
TLDRIn this video, the creator shares progress on their CCIE journey, focusing on multicast, QoS, and IP services like NTP, NAT, and redundancy protocols. Despite a sick child, family priorities took precedence, but steady study progress was made. The video explains multicast in under five minutes, describing how it efficiently manages network traffic through IGMP and PIM protocols. The creator reflects on using resources like CBT Nuggets and is halfway through their CCIE Encore textbook, targeting a slower, more thorough approach to ensure success on the first exam attempt.
Takeaways
- 👨👦 The speaker prioritized family last week due to a sick child, showing the importance of balancing family and study.
- 📚 The speaker is halfway through the Encore textbook, progressing steadily in their CCIE journey.
- 🎥 Their study method involves watching CBT Nuggets videos for a high-level understanding, followed by reading textbooks and practicing with exams.
- 💻 This week, the focus was on multicast, QoS, and IP services like NTP, first hop redundancy protocols, and NAT.
- 📖 Last week, the speaker completed topics on IP routing, including EIGRP, OSPF, and BGP, building on their previous knowledge.
- 🌐 The speaker explained that multicast solves the issue of bandwidth overload by allowing multiple receivers to subscribe to one stream, as opposed to unicast or broadcast methods.
- 🔁 Multicast uses IGMP for Layer 2 communication between the router and endpoints and PIM for Layer 3 routing decisions.
- 🔗 PIM helps routers find the most efficient paths for multicast streams, and techniques like rendezvous points are used to optimize the process.
- 🖧 IGMP snooping helps switches efficiently deliver multicast traffic only to the intended receivers, preventing unnecessary bandwidth usage.
- 🏫 The speaker highly recommends CBT Nuggets and the Encore course for deep dives into multicast, configuration, and labs, while noting their own CCIE exam preparation timeline may need adjusting.
Q & A
What progress has the speaker made in their CCIE journey?
-The speaker is about halfway through the Encore textbook and has been watching CBT Nuggets to supplement their study. They've focused on multicast, QoS, and IP services such as NTP, first hop redundancy protocols, and NAT.
Why didn't the speaker record a video last week?
-The speaker had a sick child and prioritized taking care of their family, putting family first over studying and recording.
What is the speaker's method for preparing for the CCIE exam?
-The speaker's method involves watching CBT Nuggets for high-level understanding, then digging into the details with the textbook, followed by practice exams before taking the final exam.
How does multicast solve the issue of multiple sessions in a network?
-Multicast allows the server to send one stream of data into the network, and devices can subscribe to that stream. This reduces the number of individual sessions the server has to manage, compared to unicast.
What role does IGMP play in multicast routing?
-IGMP (Internet Group Management Protocol) occurs at Layer 2 and allows a receiver to inform the router that it wants to subscribe to a multicast stream.
What is PIM, and how does it assist in multicast?
-PIM (Protocol Independent Multicast) occurs at Layer 3 and helps routers find the most efficient path to the server for multicast streams. There are various modes of PIM, such as sparse mode, dense mode, and source-specific multicast.
What problem does IGMP snooping solve in multicast networks?
-IGMP snooping helps switches manage multicast streams more efficiently. Without IGMP snooping, switches flood multicast traffic to all devices in a segment, even if they don’t want the stream. IGMP snooping ensures the multicast stream is only sent to the appropriate receiver.
What tools is the speaker using to prepare for multicast in the CCIE exam?
-The speaker is watching content on multicast in CBT Nuggets and using virtual labs to practice and configure multicast. They also plan to use Boson practice exams closer to their exam date.
What challenges is the speaker experiencing with their CCIE preparation?
-The speaker feels overwhelmed by the volume of content and is reconsidering their initial timeline to take the exam by the end of June or early July. They want to ensure they master the content and pass the exam on the first try.
What are the next steps in the speaker's preparation for the CCIE exam?
-The speaker will continue following their method of studying and practicing labs. They also plan to take practice exams from Boson and will demo these exams on their channel when the time comes.
Outlines
📚 CCIE Journey Progress and Multicast Challenge
The speaker reflects on their CCIE journey, highlighting a missed week due to family priorities. Despite not recording a video last week, they made significant progress, reaching halfway through the Encore textbook and supplementing learning with CBT Nuggets videos. The study strategy involves watching videos for a high-level understanding, followed by reading textbooks and practicing exams. This week focused on multicast, QoS, and IP services like NTP and NAT. The speaker also revisited IP routing concepts (EIGRP, OSPF, BGP). A viewer challenged them to explain multicast in five minutes, which pushes the speaker beyond their comfort zone.
🎯 Explaining Multicast in Networking
Multicast addresses the problem of one device (e.g., a server) sending data to multiple endpoints efficiently, without clogging bandwidth like unicast or broadcasting. Unicast would overload the system, while broadcasting sends unnecessary data to all devices. Multicast sends one stream that devices can subscribe to. Two main protocols manage this process: IGMP (for endpoint and router communication) and PIM (for efficient route determination across routers). The speaker explains how PIM, with modes like rendezvous points, helps find the best path for multicast streams and how multicast routing differs from unicast.
🔧 How Multicast Data is Distributed
Once the multicast stream reaches the router, it needs to be sent to the appropriate clients. The router sends the stream out, but initially, it reaches all devices in the segment, including those not subscribed. The switch handles this via MAC addresses. Without IGMP snooping, the multicast frame is sent to all ports, but with snooping enabled, the switch learns which clients want the stream, optimizing delivery to only the subscribed clients. The speaker touches on PIM modes, multicast complexity, and the value of CBT Nuggets Encore content for deeper multicast learning.
🚀 Personal Reflection on the CCIE Journey
Reflecting on their progress, the speaker shares feelings of being overwhelmed by the vast amount of content. While following along with CBT Nuggets and being halfway through the Encore textbook, they reconsider the aggressive goal of completing by the end of June or early July. The speaker emphasizes the importance of mastering the content and passing the exam on the first attempt. To prepare, they plan to use Boson practice exams and demo them on their channel. The speaker ends by summarizing the week’s focus on multicast, QoS, and IP services.
Mindmap
Keywords
💡Multicast
💡IGMP (Internet Group Management Protocol)
💡PIM (Protocol Independent Multicast)
💡QoS (Quality of Service)
💡NAT (Network Address Translation)
💡Encore Textbook
💡CBT Nuggets
💡First Hop Redundancy Protocols
💡IGMP Snooping
💡CCIE Journey
Highlights
The speaker balances family responsibilities with their CCIE study journey, prioritizing family when necessary, especially when their child was sick.
Despite not recording a video the previous week due to family commitments, the speaker made significant progress in their studies, focusing on multicast, QoS, and IP services.
The speaker’s study method involves watching CBT Nuggets first to gain high-level understanding, then diving into the textbook for details, and finally practicing with exams.
This week, the speaker focused heavily on multicast, QoS, IP services like NTP, first-hop redundancy protocols, and NAT.
In previous weeks, they finished studying IP routing protocols, such as EIGRP, OSPF, and BGP, which they were already comfortable with but continued to lab and review.
Multicast solves the problem of one device initiating sessions to multiple endpoints by allowing devices to subscribe to a data stream instead of creating individual sessions for each endpoint.
IGMP (Internet Group Management Protocol) allows receivers to subscribe to a multicast stream by communicating with the router at Layer 2, requesting specific multicast IPs.
PIM (Protocol Independent Multicast) operates at Layer 3 and helps routers find the most efficient path to a server, utilizing methods like rendezvous points to connect receivers and servers.
Switches in multicast scenarios initially flood packets to all ports, but with IGMP snooping, switches can send multicast packets only to subscribed devices, reducing unnecessary bandwidth usage.
The speaker explains the complexity of multicast and emphasizes that it requires a deep understanding of different PIM modes, such as dense mode, sparse mode, and source-specific multicast.
The speaker relies heavily on CBT Nuggets' Encore course for in-depth explanations and multicast lab configurations, praising its detailed approach.
They express a growing sense of being overwhelmed by the sheer volume of content, though they remain committed to mastering it for their CCIE exam.
The speaker considers adjusting their exam timeline, feeling that aiming for the end of June or early July might be too aggressive, as they want to ensure thorough mastery of the material.
They plan to use Boson practice exams to gauge their progress and will demo the exams on their channel when the time comes.
Overall, the speaker remains focused on passing the CCIE exam on their first try, emphasizing the importance of feeling confident in practice exams before scheduling the real test.
Transcripts
another week on my CCIE journey is in
the books what have I been up to and can
I explain multicast in five minutes
let's find out
I didn't record a video last week and
that's okay I had a sick child it's very
important to put family first and when
he's sick that's what really matters to
me I don't want to spend my time
studying and recording when I need to be
taking care of my family but that
doesn't mean I didn't make progress I've
made a lot of progress at this point I'm
actually about halfway through with the
encore textbook and of course I'm
watching CBT Nuggets to supplement that
my method has always been watched the
Nuggets first just so I get the high
level great explanation and
understanding dig into the details with
the textbook and then finish with
practice exams before taking the exam so
I've already watched these Nuggets
before I get access to watching them
before they're even released so I'm
watching them again while I'm reading
the relevant topic and this week I
focused heavily on multicast QoS and the
IP services so that's things like NTP
the first hop redundancy protocols and
then NAT so that's been what I've been
focusing on this week last week in since
I didn't bring this up I did finish up
pretty much all of the IP routing items
that I was worried about there that
would be eigrp OSPF and of course bgp
which are things that i've already been
pretty comfortable with in the past but
it doesn't hurt to dig into them lab
them up even some more so this week
somebody tweeted me and said they would
love for me to try to explain multicast
and what I'm gonna try and do is I'm
just gonna give a high-level summary I'm
gonna try and get it done in under five
minutes
this always helps me to talk about these
topics that I'm learning about too and
while I've done multicast in the past
this is really pushing me beyond my
comfort zone so without further ado
let's jump on the whiteboard see if I
can explain multicast in five minutes so
multicast solves the problem of one
device like this server here trying to
initiate sessions to multiple endpoints
what we call receivers which are going
to be these green squares that are
supposed to represent computers but I'm
terrible at drawing so in a unicast
setting all of these devices could form
sessions directly to this server and get
the streaming information that way but
that would obviously clog a bandwidth
all of these routers along the way and
the server itself would have to maintain
sessions for each one of these devices
and here we've only got five devices on
the screen but what if we had thousands
or even tens of
well that would obviously be
unmanageable a broadcast is also a way
that we could handle these situations
but now every single device on the
network has to manage that packet
whether it wants the data or not
multicast solved this problem by the
server sending in one stream of data
into the network and then the devices
choosing to subscribe to that stream if
they want to multicast packets have to
be routed just like a router has to
route unicast packets but it does all of
this subscription and routing through a
couple different protocols the first
protocol that comes into play here is
called IGMP and this occurs at layer two
IGMP is basically started by the
endpoint here the receiver who tells the
router hey I want to subscribe to a
stream that's on a multicast IP
something like 224 one two three so the
endpoint the computer here the receiver
says I want to subscribe to 224 dot one
to two to three please mister router go
find that for me there's a lot more that
goes into IGMP but that's the gist of it
IGMP just occurs between the router and
the endpoint these receiver here from
there
pim steps into play and that occurs at
layer 3 there are a bunch of different
flavors and deployment methods or modes
for pim but the idea here is that this
router at this point is now trying to
find the most efficient path to get to
the server so when all the interfaces on
this router that pim is running it will
start sending messages out to the next
router saying hey if you see a stream
for 220 4.1.2 dot three I want it now
how it arrives to this conclusion that
depends on the flavor of pim that you're
deploying there could be things called
like a rendezvous point where all the
routers check in first before receiving
the stream or these streams check in
with that first before sending it on to
a client the rendezvous point is
basically like the friend who's hooking
you up with a blind date hay receiver
meet the server server mate the receiver
and then from there they go on the date
and they figure out their own path
forward and once they figured out the
own path forward at least in Cisco
deployments the router were then build
the
fastest path or the shortest path to the
end point to make the most efficient way
to collect the stream from the server
and get it into the hands of the end
points but how the router gets it into
the hands of the end points is where it
gets pretty interesting let's clear the
screen and talk about what happens in
this link right here think about the
goal of multicast again for a moment
multicast stream has made its way into
the router and now it's time to get it
into the hands of our green receiver
here the orange receiver doesn't want
that stream it's not subscribed to it
how does it work the point of multicast
was to simply send a stream out towards
a group of clients and if the group of
clients want that stream they can access
it so by default what this router is
going to do is it's going to send that
stream into the segment which hits this
switch and the switch by default is
going to send it to all of the receivers
on that segment so even the orange
client that doesn't want that multicast
stream is going to get it and it's gonna
have to end up discarding what's really
happening under the hood here is we have
the multicast IP address the multicast
group here to 24.1 2.3 that's all great
and all because that's layer 3 but now
at this point we're on layer 2 so layer
2 technologies are what's gonna have to
carry the stream from the router into
the endpoint so what happens under the
hood is a multicast MAC address 0 1 0 0
5e and then the remaining 3 portions are
gonna be built using the multicast IP
address so just for simplicity sakes
this isn't correct I'm going to put this
1 2 3 so the destination frame will be
this MAC address the router sends that
destined to that MAC address into the
switch and here's the kicker because no
device has that MAC address as their
source that MAC address does not exist
in the MAC address table on this switch
and what does a switches default
behavior when it receives a frame that
it doesn't know the destination to it
sends it out every port in the same V
link so when the green client says I
want that stream it does begin listening
on that MAC address but again it will
never source a frame with that MAC
address so the switch will never learn
about that mac-address from that poor
again because the default behavior is
going to be descended out all ports on
that segment it's gonna get sent out
towards the orange client here too and
because the orange client isn't
listening on that MAC address it will be
dropped at the Nick that still creates a
lot of unnecessary choke in this segment
right here so what the switch kit enable
is something called igmp snooping that
way when the green client sends in its
IGMP join request basically saying hey
mr. router I want to listen to this
group the switch can then associate the
destination MAC address with that port
and it will only ever be sent out the
correct port again so that's been the
crash course of multicast obviously
multicast is a lot more complicated than
that when you start talking about the
different PIM modes like dense mode
sparse mode source-specific multicast
and one of the cool things about
multicast and specifically on core
training is that Keith Parker didn't
explain it in five minutes he goes into
detail and even demos how to configure
in-lab multicast within the virtual labs
in the CBT Nuggets encore course it's
been crucial for my multicast training
watching his content on CBT Nuggets so
if you haven't checked out the encore
content on CBT Nuggets or if you're
interested in multicast I can't stress
it enough check out the description for
my link to the Encore content and you'll
get fired up ready to go learning for
encore training so how am I feeling
overall about my journey towards CCIE
and getting towards encore at this point
and halfway through the book I'm doing
good following along with CBT Nuggets
but it is a tremendous amount of content
I'm starting to get that overwhelmed
feeling like maybe end of June or early
July is a bit aggressive I need to take
my time a little bit slower and master
this content even more I really want to
nail this exam I don't need to crush it
but I want to pass it for sure I want to
pass it on my first try so it really
comes down to how I'm performing on the
practice exams I am going to be using
the boson practice exams and I will demo
those practice exams here on my channel
when that time comes so look at that for
the end of June
but until then that's been the progress
towards my CCIE journey tackling
multicast QoS and was I
services this week thanks for stopping
by I'll see you in the next one
Weitere ähnliche Videos ansehen
IPv4 Unicast, Multicast, and Broadcast
Network Address Translation (NAT)
Understanding Protocols, Ports and Sockets | Intro to Computer Networks Course Preview
Free CCNA | OSI Model | Day 3 Lab | CCNA 200-301 Complete Course
CCIE Enterprise: How to Study SD-Access Without Breaking The Bank
All you have to do is start.
5.0 / 5 (0 votes)