In Packet Trace, I'm going to start simulation mode and then on PC one, I'm going to open up a web
browser and go to Cisco dot com.
Now the first thing the PC needs to do is determine the IP address of Cisco dot com.
So it's going to send out a DNS request message for Cisco dot com.
So scrolling down here, notice we've got a DNS query for Cisco dot com.
Capture forward or that gets sent to the rotor.
When it gets sent across.
The serial link.
Notice the DHCP is set to zero.
No quality of service is applied to this packet.
So that will go to the DNS server.
DNS server will reply back.
Packet will go back to the PC.
And now the peace he can send.
TCP traffic to the router.
PC is going through the three way handshake.
Notice.
Now we get HTTP traffic.
Notice on inbound HTTP traffic.
In this case we've got an HTTP request, doesn't have DHCP markings, but on outbound.
Out of the water.
The DCP is set to capture forward.
Notice how this packet has a little square here.
Showing us that.
DHCP was set on ingress.
DHCP is also set on egress.
So capture forward.
What you'll notice is we have this little square.
To indicate that a quality of service of value has been specified on the packet.
Inbound and outbound shows us the DHCP marking.
On the return.
No quality of service has been applied because we applied to the policy inbound on this interface and
outbound on this interface.
So on right of one notice, no quality of service is configured on the packet.
You have to think about your direction when configuring quality of service.
No quality of service is configured here.
But notice on this packet.
Going from the inside PC to the outside.
PC ingress has no DHCP egress, however, does have a DHCP marking configured.
So quality of service has been configured.
Ingress en route to and egress en route to.
So that was HDPE or let's try the same thing using ICMP.
So ping cisco dot com.
I'll put this to simulation mode.
Presenter.
Notice we have a dense.
Message.
No quality of service is applied.
On this packet.
So the package received from writer one doesn't have the DHCP configured and right.
A two is not setting DHCP on egress.
Because back to the PC.
Here's our ICMP message.
Notice inbound.
No DCP marking, but outbound out of the router.
We do have a DHCP marking.
And you can see the color here.
Notice the little pink square inbound.
We've got this DCP marking outbound.
We don't have a DHCP marking.
And that's because we configured the router to reset.
The TCP IP precedence of value to zero on egress.
So this is set to zero ingress.
A DHCP value is configured.
Now these values can be difficult to read.
Remember, the type of service field is eight bits in length, so you'd have to convert this into your
DCP value of AFI 11.
AFI 11 has a decimal value of ten or hexadecimal value of A.
You can get details of all those calculations in my CCNA course, or you can have a look online capture
forward for that ICMP packet.
There is no DHCP value, no precedence value because we reset it to zero.
Let's do something similar with PC two.
So in PC two, I'll ping facebook.com.
First packet generated as dense.
Dennis.
Will not have DHCP values configured.
Because we didn't configure that in our policy.
But notice now when an ICMP packet hits router one ingress, DHCP zero egress or outbound, the DHCP
value has been configured capture forward when it gets to router two.
Ingress of value is thus a grace of value is set to zero because we overrode it once again.
Let's do something similar with HTTP.
So on PC two.
Open up a web browser.
Go to Facebook.com.
First packet generated as dense.
No quality of service is configured on this packet again.
But.
When we get the HTTP packet.
From PC to the DHCP value is configured accordingly to one a which is a 31.
When it gets to right to.
Ingress is dhcp 0x1a egress is dhcp 0x18 and that's forwarded into the internet.
Not that the internet would do anything with the quality of service markings.
But The Slap shows you how to configure quality of service markings in packet tracer.
So were you able to complete the lab?
Were you able to configure quality of service in your network?
Did you prove that it worked correctly?