So on the subnet 1 9 2 1 6 8 1 128 slash 26.
We've been told to configure the router with the last IP address in the subnet.
Now the next subnet is 192
so the broadcast address for the subnet will be 191 which means that this router can be configured with
190
Have a look at the previous videos in this series.
If you're not sure how I worked that out, so IP address 192 168 1, 192 is the next subnet 1
91 is the broadcast, 190 is the last IP address in the subnet, subnet mask is that and we know
that from our previous calculations, the switch needs to use the second IP address in the subnet. The
router is configured with 190 so the switch, I'll change the name to switch 2 we'll simply use IP address
192 168 1 189 so 1 less than the router
no shut the interface so ping 192 168 1 189.
That's our local IP address.
Can we ping the router?
Yes, we can.
I'll also configure a default gateway on the switch pointing to the router, switch is configured, so the
switch once again is using 189.
The DNS server should use 188
one less than the switch, so static IP address of the DHCP server is 192 168 188 subnet mask is 255
255 255 192, default gateway is the router 192 168 1 190 again that's the IP address of the router DNS
server will be Google.
So on the server, can we ping the router, type that right.
Yes, we can.
Can we ping the switch?
Yes, we can.
Can we
ping the DNS server?
Not at the moment because we need to configure the serial interface of the router.
But now let's configure the DHCP server, so DHCP I'll enable the DHCP service default gateway is gonna
be 192 so 1, so 192 168 1 190 DNS server is Google, IP addresses that we'll allocate
are 192 168 1.
Now you need to be careful.
The first host is one more than the subnet, so it's 129.
Maximum number of hosts
I'll allocate is 50 and I'll save that configuration.
You could allocate more IP addresses in your pool or less if you wanted to so.
So for instance only allocate 10, just depends how many IP addresses in your subnet you want to have
for static IP addresses.
How many IP addresses you want for dynamic IP addresses. So on the PC, IP config, IP address has been
allocated.
Ping 192 168 1 190.
That's the router,
that's the switch, that's the DNS server.
What about PC 5
just do one more here.
IP config, IP address has been allocated.
So can we ping the router?
Yes, we can.
What about switch?
Yes, we can.
What about DNS server?
Yes, we can.
We won't be able to ping 192 168 1.1
PC in the other subnet because we still need to configure this serial link, so let's configure the
serial link the IP address of this router on the serial interface is gonna be one more than the subnet.
So show IP interface brief.
This serial interface needs to be configured with IP address 192 168 1 subnet is 192.
So, first IP address will be 193 with that subnet mask.
So can we ping 192 168 1 193.
It won't work at this point because we need to configure the other side. So on this router show IP interface
brief we still need to configure the zero interface it's currently down, so no shut that. IP address
will be 192 168 1 and this is a little bit more difficult to work out the broadcast for the subnet.
Again you just populate the host portion with binary ones and what you'll notice is it's full of ones.
So that would equal 255, so one less than the broadcast is 254.
So 254 subnet mask is that no shut the interface again so show IP interface brief according to this
it's still down.
Let's make sure that I've configured it right.
Show IP interface brief,
I may have connected the wrong serial interface in this network and that looks like what I've done, wrong
serial interface.
So what I'll do is delete that serial interface.
I'll fix it in your lab so you don't have that problem.
That serial should be connected to that serial, so show IP interface brief this interface is up up
so can we ping 192 168 1 254
Yes, we can.
So router 2 can ping the Internet router, so hopefully, these PCs can now ping the Internet which
they can, notice they can ping cisco.com as an example and they can ping facebook.com.
So going to the web browser on PC 3, can this PC get to cisco.com?
Yes, it can.
Can it get to facebook.com?
Yes, it can.
What about PC 5, web browser on PC 5.
Can we get to cisco.com?
Yes, we can.
Can we get to facebook.com?
Yes, we can.
We can access these servers on the Internet.
We've had to do quite a lot here, as a last test.
Can the PCs in the 1 subnet ping PCs in the other subnet, so can we ping 192 168 1.
1?
Yes, we can.
What about 1.2?
Yes, we can.
And if we trace to that, we are essentially sending traffic to router 2 then to the Internet router
then to router 1 and then to the PC in the other subnet.
Okay, so this was quite a complex lab we had to do a lot of things here, but I'm hoping it's helped you
understand subnetting and way you use subnetting and how to use subnetting in a practical lab.