So he has rather three show IP protocols.
Shows me that no protocols are enabled, so no routing has been enabled on this router rather IP.
100 network.
So I'm going to enable IGP on this interface 10.1 102.3 and I'll do this specifically down to IP address
using an inverse mosque.
So I'm only going to enable IGP on this interface.
Notice to neighbor relationships have been established.
Router three has a neighbor relationship established to switch one over here as well as to switch to
shown over here.
The reason why it forms a neighbor relationship with both switches is because router three is connected
to VLAN one.
So there's a layer two connection all the way through to switch one.
This router once again doesn't exist in the topology.
It simply represents a virtual HSP router, so that router doesn't actually exist in the topology at
all.
Wrote a three once again has a layer two connection to switch one as well as switch to so hence it forms
a neighbor relationship with both.
So do show IP err GOP neighbor.
We can see our two neighbor relationships both formed on fast ethernet zero zero do show IP protocols.
We can see as an example that it's routing for this network and it's got two gateways.
Automatic summarization, however, on this router is enabled by default.
So I'm going to type no order summary to disable automatic summarization.
The neighbor relationship reconfigures and we can see that automatic summarization is now disabled.
Do show IP route.
We can see that the Rada has learnt about two routes through air GOP.
It's learnt about network 10.1 or 10.0 via both switches and it's learnt about Network 10.1 or 20.0
from both switches.
So in other words, this router has two ways to get to VLAN ten and VLAN 20.
Now let's test some connectivity on router one, which is this device over here.
Show IP rot.
It has a default gateway pointing to the ISP router.
And in this case.
So which one should be the active router for HSP on that VLAN?
So on VLAN ten, the local router is the active router.
So switch one is acting as the active router for HSP.
So let's check if rata one acting as PC one can ping other VLAN addresses attended 1.101 is it able
to ping this VLAN vlan one on switch one and it can in this example.
What about 253 router three?
So this router can now ping this IP address on router three.
Let's add a network to the topology.
So I'll create a loopback on router three of quadruple three.
Can this PC ping that address?
And at the moment, it can't.
It's getting unreachable messages.
Let's see from who.
So debug ip icmp do that ping again.
Rather three is getting an unreachable message from 10.1 to 10.1.
In other words, switch one, switch one doesn't know about quadruple three.
So this router acting as a PC is forwarding the traffic to the HP virtual router.
That traffic is being forwarded by switch one, but switch one doesn't know about this loopback that
we configured on router three.
And that's because that route is not being advertised in air copy.
And we can see that by using the command do show IP protocols.
Only Network ten is being advertised.
We can also look at the running config.
So do show run pipe section IGP.
We have only enabled IGP on this interface.
We didn't enable IRP on the loopback of router three.
So I'd rather three rather ERP 100 network quadruple three and I will match it exactly.
So Showrun.
Section II GOP.
We have now advertised that network in GOP does switch one now know about that network.
So show IP route on switch one.
Yes, it does.
It's learning about that network from ten .1. 100 253, which is router three.
So can router one acting as our PC now ping quadruple three.
Previously this didn't work, but notice now it does work.
So the ping.
Succeeds.
Debug is just showing that output do the ping again.
Rather one is now able to ping rather three of via and this is the important piece of via its HSP default
gateway.
Ken brought it to acting as PC to ping that loopback as well.
So let's test that.
Here's router to show IP route.
Notice no routes are shown because on this router I disabled.
IP routing.
So show run pipe include IP route.
Notice the IP routing command is disabled, so just do a show run without piping so that you can see
where it is in the config.
Notice no IP routing is disabled on this router.
So what we did in a previous video is specify a default gateway.
So this command was added to the configuration show run pipe include default allows me to see that so
this root is now acting as a PC and it can also ping this loopback.
The IP default gateway command is only used when IP routing is disabled on a router.
If you have IP routing enabled, then you need to use.
The IP route command to create a default gateway like we did here on router one.
So basically we now have full connectivity between these devices in the topology, these routers, camping
router three.
The next step is to advertise a default route in router three so that these two switches have router
three is their default gateway.
And we need that because we want to configure NAT on router three to allow these devices to connect
to devices on the internet.