Hi, Daddy.
This might have that here again.
So now we have to speak about the poem Bootstrap or Bazaar.
That's something we can see it if we go to the market.
It.
Rather on the routing over here inside when we have this one, the BSR candidate.
So what this has to do in pain.
So let me explain to you what it's exactly.
So BSM is bootstrap.
It's a protocol that is used to automatically find the rendezvous point on our multicast network, so
it only just check for you what is the rendezvous point to be able to let all that out or knows about
the rendezvous point?
Mission is an open standard protocol.
That means it can be used on my colleague, but it can be was also on any other vendors which support
multicast.
Now Cisco has a similar protocol which is called auto r.p, but it is Cisco proprietary.
So we are working on migrate it now, so we have to forget about Cisco.
So again, we can see that it is offered that the BSR candidate and the RB candidate.
So we will see that the how many BSR candidates can you can have on your network.
You will see that you must have only one virtual candidate and the are p candidate means those are the
deltas that they want to become the RB the rendezvous point.
So let's see in more details about the BSR.
So the obvious candidate again.
BSR Candidate What does it inform other office that there is a rendezvous point on that IP address?
So it's sent based on message, on hop, by hope basis, by sending a packet to this multicast 2 to
4 zero zero 13 with city ad one what does it mean?
TTL one That means it will inform the next charter next to it.
It will send a message at that time.
That is the information that you want.
Where is the rendezvous point and is it the AL one?
So what does it mean tr1?
That means that the packets will not be routed after receiving the parameter because the TTL is wrong.
So the title of one is this one.
Then this bucket will not be routed to other others.
Now, once the peers receive this machine, then they will send it to all the PIM enabled interface.
So once it received to the router that no not the reception will re send it to all the other interfaces.
Now that BSR message, what does it contain as information?
So it has the information about the browser itself and the IP to a group mapping.
So say that you have for example, two or three groups that are used for multicast 239.1.223 and 239.4.5.
The six and 239 the 7.8.9.
Each one is making multicast for something.
Now on each of those groups you need a rendezvous point.
So the BSR, what is doing?
We will put for you the list and this will inform the other authors using the BSR message.
They will find out that others that you have a rendezvous point for this group on this hypothesis.
You have another rendezvous point for that group on that IP address and so forth.
All right.
Now it's really important that you should only have one active BSR in a network in case that is.
And that's work where you have more than one BSR because the rule is to have only one.
But in case you have more than one, what's going to happen?
Then?
The BSR actors will listen to the messages of other BSR routers, and the one which has the higher priority
would become the active BSR.
So the message will be listening to the message of each other and the one which which has the higher
priority as the one which becomes the BSR of that matter, because you need to have only one BSR and
that's where it goes.
The priority is the same.
So if they prioritize, then the other, which has the highest IP address, would become the BSR again.
So if the priority is the same, then they will check between each other who has the highest IP address?
And then he would become the best out of the network.
So this is an example here throughout history as the BSR Ishan to all his interfaces which I have the
amount the cash enable on them or depend this on message on the network or on the multicast address
2 to 4 zero zero 30.
Now what with comes to router one out of one will send it to a rate of two.
And so for sure at the end everyone will receive the BSR message.
So that's what the BSR must be.
Let's see now about the IP candidate, because we can see over here if we go to the pen.
So that is the BSR.
And you can see over here this is the priority that we are talking about now.
We have the R.P candidates.
So also the RB candidate means that you will have to say which router want to become the r.p for which
multicast group.
So IP candidates.
The other authors that want to become.
The rendezvous ponder by announcing themselves to the BSR.
So they have just to mention to the BSR we want to be the RB for that group so one that candidate accuracy
by BSR message.
It knows the source address of the BSR and it will send the RB an announcement to the BSR using unicast.
So what will happen?
Because we saw in the previous slide that the BSR will send the message right to all the authors down,
so the routers will know what is the IP of the BSR, right?
So what they'd rather that want to become the RB, they will send a unique to the associate that I want
to become the RB for that, the group for example.
So here we can see this is an example rather two and a lot of text.
They want to be the RB and the BSA is here on the rotisserie.
So that two was sent the RB announcement to be a shoutout to him that I want to be the RB, for example.
2239.122.3.
This one also send it to the BSR as unicast, saying to him I want to be the RB, for it could be for
the same group, it could be for another group, but let's say it's for the same group.
239.122.23.
So once we have this case like two routers want to become the RB for the same group.
We have to see what will happen in this case.
But before we speak about that, let's see what is the other information about the RB candidate now?
What's going to happen that from his side once the RB are not should receive body?
Bashar Assad has received the RB announcement.
He knows which other want to be, the RB for which group.
Then he will build the list of RB and what can you be sure of?
That is what we called the group to RB.
So the BSR will make a list and he will say, okay, I see that they're out there.
Let's check here.
Router two yeah.
Router two want to be the r.p for 239.1.2.3 router six also want to be also for that group.
So we just put them in a list.
Now, after you have this list built on the browser, he will include it inside the baseline message.
So the baseline message that the wizard designed it, we saw it over here on the 22400 13.
Then he would include this list.
Then all the others which have the multicast enabled.
They know about the artists.
So this is how the artist can be known.
So using the BSR router by the bedside messages.
Now let's say that we have two or three aapis for the same group.
So how this will be solved?
How can we have only one r.p for that?
The group are not three or four artists.
So here, once the whole router received the BSR messages with the group or the list of the group that
the BSI were provided, then the modification AB Oracle will have to select the best r.p from the list.
When you have multiple aapis, it may happen that those are PS want to serve the same multicast group
for example.
You have to agree that they want to serve the group.
239.122.3.
Which of these two r.p should be chosen?
So which of these two rather will be chosen as the RB of that group?
So what is going to happen that all good authors would receive the BSR message?
What they would do, they will look for the longest mush.
For example, if you have a multicast group of 239.122.3 and you have two RPF saying that they want
to be the artist for this group to talk to routers.
Now, let's say that one of the routers is advertising that you want to be the RB to serve the 239.0.0.8,
which means he was also be serving this group because it is such a solution, not the 00.0/8.
That means of course is also serving two senado wanted to the stream.
And we have another one saying that they want to serve two Senado 1.2.0 slash 24 group.
So here the wrappers will choose the longest mush, which is this one because this one is slash 24 is
more precise.
So in this case, the router would say the RPO would be the 239.122.0 slash 24 thereafter, which is
serving this Market Garcia group.
So that is the first thing as the longest.
It's always the better for the others.
Now, one two routers advertising the same exact signal, for example, both of them the say 239.122.3.
So they want to be the r.p.
2239.122.3.
Then the RB with the highest priority would be chosen.
I'm not the best candidate.
The high priority here is the one which has the lower value.
So higher priority on the r.p is the one which has the lower volume.
And that's something we can see it also over here.
When we go to routing, we go to PIM inside the RB candidate.
You can see over here we have the priority.
So the value which is lowest then is the one which will win.
Now the last one is of the groups and the priority times.
So we have two daughters that want to serve 220.12 to the three and both of them they have priority,
for example, of 192.
Then in this case, the R.P will be the one which has the highest IP address.
So the one which would be having the highest IP address will become the RB.
All right.
So now we understand the concept behind the BSR and the RB.
So I can remember BSR is nothing more than its share out there.
Which standard based on messages, including the list of the authors and the group saying that is the
RB for that data multicast group and then all the authors knows about it.
So then in this case, if you have, for example, many routers inside your network and you have one
R.P, instead of going to each of the router, put the RB manually there.
You can just configure BSR on one of the others.
And then this would be informing all the authors who is the RB.
So I hope that this lecture was informative for you.
And the last lecture I'm going to do the lab to show you how this would work.
So here, the upcoming lecture.