Neighbor Discovery Protocol

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23 hours 18 minutes
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Hello and welcome back to ice. Indy one interconnecting Cisco Networking devices. Part one This is episode 73 to the neighbour Discovery Protocol er, ndp on trend Darryl No beer structure for this course last video which went over these 7.3 introduction
and in a few pre assessment questions here
in this episode of recovering how the hosts and routers utilize NDP to gain information on their local link.
So are learning to check to see if we're gonna look at how any peas used for rowdy discovery. We're gonna learn how it kind of replaced the AARP with the neighbour Mac learning. And also, we're gonna figure out how the duplicate address detection or Dad is also utilized.
A quick pre assessment. Here, What address does the outer solicitation message gets sent to? Hopefully, you should have heard this from the
introduction video.
All right, FF zero to come calling to the all routers multicast.
All right, so NDP, it's used by the so we can use it for router discovery. If you're a host,
we use it for slack. Where is going to use the stateless address? Auto configuration is gonna learn that first part of the address in the prefix length. Right?
Um, we're gonna learn about the other address, or there are devices that are on that subject. I learned the Mac address. We're gonna use the duplicate address detection so that we're gonna go over, but it kind of just waits to see if anyone uses that address. It kind of, uh you'll see it sends out a message saying, Hey, is anybody using this address?
And if no one replies, then it'll it'll say, OK, no one's using it were cleared. Use it.
But anyway, we'll get into the router discovery here. So the first thing that a hostess gonna do is gonna send a router solicitation message to the multi cast address of F F zero to Colin Colin to the all routers Multicast address. Remember the that multicast address? It does not get sent out of that sub now to that mold local link.
The router will not for that message on.
So anyway, the router receives that message,
and he's gonna list that local link I p B six address of the router and say, Hey, I'm here. You know, I'm gonna be your default gateway.
Um, here's our prefix that we're using our subject. Here's the prefix length were using and it's going to send the information back to the host,
right? The destination is gonna be that, you know, cast of that host, Um, or if it doesn't know, because every once in a while it will actually just periodically send out these router advertisements just on the sub nights, just going to send him out saying, Here's our prefects here. Pretty fixed length years with my I p address.
It's gonna advertise all those details back to that host or periodically back to the all host multicast address.
So if we move into the neighbor Mac address learning these neighbors solicitation and neighbor and advertising messages, they are kind of like the i P version for art messages. So the N s message has for information, and then you're N a is your response. You have your host that's looking on the network saying, Hey,
I'm trying to figure out if anyone is at this Mac address,
um, using that solicited node mag address that
we learned about before. Remember, that's the last six digits. Eso these could be duplicated dresses and said, Hey, here's gonna send out this message to the solicited node multicast looking for the smack.
And then the someone's gonna receive that if their ad that solicited solicited node, multicast address and say, OK, I'm not this address. Here's my Mac address. It's gonna send it back to that original sender of the neighbor solicitation message,
and every once in a while, it's just gonna also just send it out to the all hosts. Are all nodes multi cast a draft of dresses F F zero to coin colon one
that's going to anyone. Well,
so think of this. One is kind of it is the replacement for AARP rights learning the Mac address Binding? Um, kind of.
So we kind of lastly get into the duplicate address detection or Dad. It's going to also use those neighbors solicitation and neighbor advertising messages
for that sub net. So what it does is is going to send out a solicitation message with the address of the host that it wants to use as a target address.
So it's saying, Hey, this is the address that kind of like I'm trying to use, and if no one has that address is just going to sit there and say, OK, cool. I can use this now if they do receive a message back because someone on that
sudden it has that addresses could say, Hey, okay, here is my address. And also here is my Mac
s. So that way it knows that someone is currently using that address.
So for getting to the episode recap here we went over the neighbor Discovery Protocol Basics. We looked at Roger so station advertising messages and finally, the neighbors. So station advertisements is mirrored the router. So station advertisement will give you it can give you the prefix prefix lengthy router during the default router default. Gateway would have to call it,
um, the neighbors. So station does Mac address learning it Does the duplicate address detection?
It's only issue. We'll figure out this PO assessment here Which message will have a response with the prefix length. So think about that for a second.
All right, the router advertising to remember is the response to the router solicitation message that will have your prefix pre fixed length and the defaults, router
or mac address.
So in the next steps over and look at the differences and comparisons to stateless and state fel de A C P. We're gonna take a look at how compares to the I P version four d A c p.
And as always, if you guys that questions need out, feel free to shoot me a message. Otherwise, thank you for watching this episode. I look forward to seeing you arrest him.
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