Okay so that means I need to configure a rod for the Internet router so do write a full first
interface serial.
0 1 0.
That's this interface.
Now in the real world you could use commands such as Show CTP neighbors to verify neighbor connectivity.
If you're not sure how interfaces are connected and you want to verify interface connectivity.
So this is definitely the local interface connected to the Internet right.
So on that interface interface serial 0 1 0 IP address 1 9 2 1 6 8 1 1 1 7 first ip address and subnet
is one more than the subnet address
and because this is a slash 30 the last IP address is simply the next IP address in that subnet interface
serial.
0 2 0 IP address 1 9 2 1 6 8.
We're in the subnet so it would be 1 1 8 1 1 1 8 slash 30 mosque.
So can we ping the other side.
Yes we can and we can see that an SPF neighbor relationship has been established.
So back on router 4
we see if neighbor relationship is established.
We've learnt a default route via the Internet router so IP domain lookup IP name server is going to
be Google paying Cisco dot com we can ping Cisco dot com can be paying Facebook dot com yes we can solve
configured the wine links and updated them per the new subnets that we have the next step is to configure
the subnet so we need to use this subnet for this local area network now the way that you work out first
host last host broadcast is once again first host is simply the next IP address after the subnet so
binary it would look like that host portion is set to zeros except for the lost but which is set to
1 but in decimal it's simply add 1 to the network portion the broadcast would be one less than the next
subnet so the next subnet is 80 so the broadcast would be seventy nine and to work out the broadcast
portion youthful the host portion with binary ones
and again we can verify that we've done a right 79 it looks like this in binary so 0 1 0 0 followed
by full ones so that's correct and then the lost hosts in the subnet is 1 less than the broadcast address
so 78 and if you want to work it out in binary you set the host portion to binary ones except for the
lost but which is set to zero whose portion for subnet looks like that filled with zeros broadcast is
filled with ones first host is filled with zeros except for the last but which is set to 1 a lost host
has it fold with ones except for the lost but which is set to to 0 so the lost IP address in the subnet
which we need to use on router 4 is 79.
So 1 9 2 1 6 8 1 79
so on the Ethernet interface connecting to the switch gigabit 0 0 0 IP address 1 9 2 1 6 8 1.
And again it should be 78
subnet is a slash 28 so slash twenty eight equals eight plus eight plus eight
plus one two three four binary ones
so it's 2 5 octave 4 5 4 binary ones in an octet would look like that followed by four zeros which gives
us to forty so this is 240
if you want to verify it again in our calculator to looks like that
switch needs to be configured with the
second lost IP address I didn't do that here but it's essentially one less than the last IP address
so the switch needs to be configured with 77
so quantity interface VLAN 1 IP address 1 9 2 1 6 8 1
77 slash 28 can we paying 1 9 2 1 6 8 1 78 so can the switch ping the router make sure that I've done
it writes a show IP interface brief
switch should hopefully be able to ping itself.
Camping itself.
Let's see if we can ping the rod again
on the rod US show IP interface brief can we ping ourselves can we ping the switch
now notice the switch has some old configuration on it.
So that may be causing problems sometimes in packet tracer when you make changes things break you may
have to restart packet tracer let's just make sure that I haven't done something dumb that all looks
right that all looks right shows GDP neighbor details we can see the Internet router
we can also see the switch with the correct IP address
the local port is this port another side is that on the site shows GDP neighbors we can see the router
on gigabit 1 0 1 that looks good let's see if I've done something wrong what I want to do at this point
is save packet trace and started up again and see if that solves the problem otherwise I'll check if
I made a mistake packet tracer has booted up again here's the router
a for show run just to confirm that this IP address 1 9 2 1 6 8 2 1 78 slash 240 is configured on the
router
and on the switch switch 3
show run this IP address 1 9 2 1 6 8 1 seventy seven slash 28 is configured on the switch that's the
second lost IP address so ping 1 and 2 1 6 8 1 77 switch camping itself cannot ping the router
still having problems
I'm going to remove this default gateway command.
Change it IP default gateway
190 1 6 8 1 78.
Let's see if that solves the problems
and it did on the real world.
That's not correct in the real world.
You don't need a default gateway to access a local device but that's a problem in packet tracer.
So the issue here was the switch wasn't working.
A real switch in the real world you wouldn't have to do that even though the default gateway is wrong
because they are on the same subnet.
They would still work.
In other words it still be able to ping each other.
Can the switch now ping Cisco dot com.
Now I've rebooted Packet Tracer so it may take it a while to sort itself out packet Trace is great.
But it does sometimes do things that are not real world and sometimes has weird issues but at least
it gives us the ability to test things and to learn.
Okay so the switch can now ping Cisco dot com.
So that's good.
We have IP connectivity from the switch to the Internet.
We then need to configure the pieces with the first ip addresses in the subnet.
So on the P.C. Foster Ethernet a zero interface.
1 9 2 1 6 8 1.
IP address is going to be 65 first ip address in the subnet.
So 65 subnet mask is 2 4 5 2 4 5 2 4 5 240 default gateway is gonna be 1 on 2 1 6 8 1 78 DNS server
is going to be Google.
So hopefully this piece he should be able to ping Cisco dot com which it can and hopefully should be
able to browse to Cisco dot com which it can.
And what about Facebook dot com.
You can also browse to Facebook dot com so that works well.
Next P.S. IP address is going to be statically configured 1 9 2 1 6 8 1 to be 66 next IP address in
the subnet 2 4 5 2 4 5 2 4 5 2 40 default gateway is going to be 1 on 2 1 6 8 1 78 so can it ping Cisco
dot com spelled that wrong
can't find the domain name let's just check that I configured the DNS forgot to do that.
So DNS needs to be configured it can ping Cisco dot com cannot get to Cisco dot com yes it can.
Can it get to Facebook dot com.
Yes it can.
And then the lost P.S. In that subnet needs a static IP address of 1 9 2 1 6 8 1 67 2 4 5 2 4 5 2 4
5 2 40 default gateways 1 9 2 1 6 8 1 78 DNS server is Google we should be able to paying Cisco to com
which we can and hopefully at this point will be able to browse to Cisco which we can and browse to
Facebook dot com which we can.
So I've successfully completed this lab.
I've taken the subnet and broken it up into as many subnets as possible each having 8 hosts per subnet.
That's what we did there.
Then I took the last subnet and subnet ID it again and used these two subnets for the one links.
Notice we still have these two subnets available and these two subnets available so we've conserved
IP addresses in our network rather than using a slash 26 which is very wasteful.
On a when link we using slash 30s on two one links and we've used one of the subnets for a site and
we've got more spare.
So what we should do is subnet this one as well.
So what you would do in the real world is make this a slash 30 and better utilize your IP addresses
but that's okay for this lab.
I've completed the slab.
How did you do.
Were you able to complete the lab yourself.
IP subediting is really important for the CCMA exam.
Make sure you understand how to use a variable length subnet mosques are like I've done here.
Make sure that you understand how to subnet and how to allocate IP addresses to devices in subnets.