DHCP Concepts

Video Activity
Join over 3 million cybersecurity professionals advancing their career
Sign up with

Already have an account? Sign In »

23 hours 18 minutes
Video Transcription
Hello and welcome back, Tyson. Do you want interconnecting Cisco networking devices apart? One This subset 532 D h e p concepts and threatened a wannabe instructor for this course. The last video we went over the 5.3 overview and some pre assessment questions
The subsidiary incurring the basic DCP concepts and said on a D H E p relay agent
and learning objectives again, we're gonna go to the D A. Should be conscious. We'll look at the different messages that air sent between the client server and then we're going to set up one of the routers for a relay agent, which we will actually implement in the next episode.
As always, a quick pre assessment here to get is going. What is the destination? I p a foray discover D H E P packet that it would be sent by the client.
I will give you a few seconds.
All right. It is the to predict fire to fire, to require 2 35
And we have to seem like diagrams we've been working with in this module. Ah, we're going to continue. We're gonna leave the rip routing on, so if you still have that wonderful If not, please go back and set it up. We do not need to set up router one with the outside Internet.
A CE we could actually conflict with th e p settings if you have looked at your soul router. So we're gonna just gonna have a standalone lab now. Um, so please remove that if you can,
uh, another rose will get right into it.
The dynamic host Configuration protocol or D h E p. What it does is it's going to assign your i p address your default gateway. Sudden it, Master Dina server all that to the client.
So originally, when a client first gets on network and it's set for D h E P is going to send out a discover packet What that is is it's looking for a d h e p server with a source. I pee off 0000
and a destination of the to modify it to certified too petrified to 55 broadcast I p address.
So you gonna marry you? Think about what is on a land, right? For now, we're gonna assume that the D A. C P server is on the same land as the client. So the D A. Should be re server catches this packet looking for that destination address,
and it's going to send back a offer packet
to the client.
It's gonna say, Hey, uh, I had this I p address if you want it,
you know, respond If you D'oh
and the request is gonna be some about a client and that says OK, yeah, I like that at P. Go ahead and leased that tomb in here. You know, Give me that I p address. I want that,
And then the last message is gonna be from a server and that says, OK, I'm assigning this I p d you. By the way, here is your subject mask. Here is your default gateway or the default router.
And here's your Dina servers. Um,
you could still statically you sign your DNA service, but the D S P server will have its own set that we will send to the client
and the way that we always that I always remember the messages is Dora. Deal are a door discover offer request acknowledgment.
just know it starts with clients and ends with server.
So the three different allocation was we had dynamic automatic aesthetic, these air, the allocation most of the server uses so dynamic. What it does is it just has a pool of addresses
and, you know, whoever gets to him first, it's just gonna sign him out. Say, okay, here's an address for you. Here's the address for you.
Um, it's just, you know, uses them. There's really no rhyme or reason. It just has a pool. That it's just pulling from
automatic is you can set the least time that the I P addresses used to infinite meaning that that's I p
is set like
to that client indefinitely. Meaning is that client comes back on the network at any point.
He's gonna have that same i p address as he did, you know, years passed, If that's the way it's been. Sit.
So we still have that pool, but it's going to say, OK, this client A is always gonna have this I p address.
And then, of course, we have the static, which you can assign on a D h E P server. This is okay. When this client is looking for an address, give him this one before. This is all pre configuration. Right before the client gets on a network, you take his mag address
and you say for this Mac address, we're gonna give him this I p address for every device. So you a lot of times, this is very useful for servers for printers. Anything that you know is not gonna be swapped out in the near future. That's always gonna be statically signed something that's, ah,
business essential. He'll want to have that.
So what a d h e p really agent is You think about it for a remote sub net. So if that d h e p server is not on the same land as that client, this is where it's necessary because you think about the router receiving that 2 55
broadcast packet he's gonna go. Well, I'm not gonna send this out. And why? Why would I?
You can actually set up. It knows that when that to 35 comes in is looking for a g h e p. But if you can set up this I p helper address command under an interface where the land is connected to the switch where the router is connected to the switch. You set it up in that land port.
This I p hope her address. What it does is it Will Ford on that broadcast packet to the D h E p server. Right?
So it's gonna do is gonna change that source I p of 00000 to the routers. Incoming interface. So where the land is connected,
and then the destination I p is gonna be for the D A cheapie servers. I p because that way, we'll have a route to it. And, you know, everywhere down the line will have a route to it as well. And also, they should have a route for that source, i p
because it'll be on that land, and then eventually the discovery packet goes out than the server responds with the offer packet,
and it's gonna have that same information. Except, you know, flip flops, source and destination. We flipped.
And that server, the routers gonna receive that packet and say, OK, this is supposed to go to this Mac address.
so it's gonna change all that information on the flight. Kind of.
So what we're actually gonna do here I'm just going to set up Router One is a really agent pointing to Router three. So we are actually going to set up around three in the next episode as a D h e p server
and router one that land that is on Router One. Attend that one. That one slash 24 is gonna be requesting the i P addresses.
So I will go ahead and bring up the putty session here.
All right, so we're on router one already.
Get this going.
So we need to make sure I'm gonna make sure that we still have our routes. Should be route. We have a rip routes.
Okay. I just want to make sure that we have cut conductivity to 14.2
and we can ping road us free.
So what, we can dio if we do a I want I want to do a show CDP neighbors to see where we had that switch connected to. And that is on fast season at 00
So I'm gonna configuration terminal vest. Ethan, that interface
interface precedents zero.
And we'll set up the I P Helper. It was
up here, so the i p destination
it is going to be 10 dot wanda for that, too,
and we don't decide. It doesn't see soldiers to enter
this way. When the device the soc Callie v. M that's actually gonna be in that that land up there when that goes on and requests that for and I appear for a ah d htp requests it's gonna Ford that I p her Ford that request on the router three we're gonna set up in the next episode as a server.
Setting up a real agent is a simple is that,
um, goes on the land in her face and it points to the server.
You wanna minimize putty
and we'll go on
from her. The recap here we have our GHB concepts. We have the Dora messages, the discover by the clients he offer by the server the request about a client saying, Hey, I want this I p And then the acknowledgment from a server saying, Okay, here's your i P. Here's your sub night. Here's your default gateway here, D N s,
And then there are the source I pee on. The discover will be 000 and the destination I p will be to modify it to beautify 2 to 5 to 55.
So go ahead, move onto the post assessment here. Which interface on Roger One with the helper address
be set on.
So we will remember that. You said th e p server. We're working on Router won the Abou to laptop. Needs to have a P addresses looking for that I p address. So think about where you're gonna set the
hope her address on gave a few seconds.
All right, Hopefully you got fast. Internet 00 That is the one connected to the land.
And as a citizen accepts that we're gonna set up the router three as a d h e p server.
And as always, if you guys have questions, need help. Feel free to shoot me. Message. Otherwise, thank you for watching this video for the senior next one
Up Next

This course will enable students to understand virtualization and cloud services, and network programmability related to LAN, access and core segments.

Instructed By