Now before we can figure out tunnel's we need to make sure that the tunnel endpoints points have connectivity
to each other.
So Ratatouille should be able to ping a.
And vice versa.
In this example I'm going to set up the tunnel from the serial interfaces so logically it looks like
we have this separate tunnel interface but the tunnel is actually configured from serial 020 to serial
020.
So router 2 can be paying for that one two to two yes we can and on Radio 4 Kemy paying for that wonder
one to one.
Yes we can now ping uses a different protocol to Geo re.
So you need to confirm that you have connectivity using GRV from this interface to this interface.
But for the moment we've used ping as our initial test to ensure that we have basic connectivity so
to configure a tunnel you go convert the interface tunnel and you specify a number I'm going to choose
0 to keep it simple.
But as you see there's a wide range of HTML numbers that you can choose from tunnel's 0 and this example
has gone down the tunnel interface will only come up if we have IP connectivity to the tunnel destination
which we still need to configure.
But first let's configure an IP address on the tunnel and I'm going to configure this as a slash 30
network and once again we're going to use a private IP address.
So we're going to be sending traffic across the Internet using private IP addresses but it'll work because
Rodda 3 is going to route traffic based on the hour ahead.
Or as described in the OR if he is the delivery header so the GRC header and payload packet is not going
to be read by the Internet routers.
They are simply going to ratchet traffic based on the delivery header.
We need to specify the tunnel mode
notice multiple options are available but we're going to use Chiari and IP version 4 that is actually
the default.
So when we look at the tunnel interface you'll notice that command doesn't display because that is once
again the default tunnel mode.
You don't need to specify the tunnel source now just the tunnel command gives you multiple options.
We've already chosen mode but now we will select the source of the tunnel.
You can choose a physical interface or not address.
In this example I'm simply going to choose IP address and hit enter.
The tunnel is going to originate from this IP address and it's going to go to a destination for one
or two to two.
In other words Rodda for as you can see the tunnel has now come up and that's because we have IP connectivity
from this router to the destination of the tunnel.
The tunnel however is not going to work because we have to configure the other side.
So comfy interface tunnels zero on route for IP address tend toward one or three to.
Keep it in the same subnet.
So the Saudis once again 10 to 1 2 3 to 1
and the side is 10 to 1 2 3 to 2 sit back and write a for tunnel mode GRV might.
You don't have to specify that come on because it's the default but I'll do it here for completeness
tunnel sources for Wonder 1:58 tunnel destination is Forder wonder wondered one and hopefully what we
should see is that that tunnel comes up and there it does show IP interface brief shows us that we now
have a tunnel interface that's up up on the side and on Rodda to
the tunnels up on router to send router to we should be able to ping wrought a forest tunneling to face
which we can.
So no just we pinging that one two three to two.
But rodded 3 has no visibility of that route.
And that shows quite nicely that rotisseries able to route traffic from this IP address to the IP address
without actually reading those IP addresses.
It's simply writing traffic based on the source to the destination.
So let's prove that I'll start a capture here I'm going to start a capture using HDL C because the default
encapsulation is HDL C on Siska serial links on interface serial to one on router three.
So at the moment we see CTP we see some other the messages but what I'll do is do a ping from Rodek
to Toronto for again.
And there you go there's an ICMP messages
so you can see it's an ICMP from 1 2 3 to 1 to 10 to 1 or 3 to 2 The lead to encapsulation is HDL see
the protocol used at least 3 is IP version 4.
And notice the source and destination IP addresses for that wondered wondered one destination is 4 1
2 2 to 2.
In other words this router is sending traffic to this router.
Rotisseries going to route based on these IP addresses not on the IP addresses contained in the encapsulated
packet at least for we can see Jari.
So generic writing cancellation using IP version for and inside there we can see the source tendered
one or three to one and destination of tendered one to three to two.
In other words we've encapsulated an IP version for packet within an IP version 4 packet the original
traffic was a pain.
So there's the paying.
And if we go to the next packet we can see the ping reply and kept isolated and not provision for with
injury within our provision for within HDL see.
So we've now successfully configured a tunnel from rodded to Toronto for I'll stop that capture in the
next video.
Will check whether one can ping wrote a five decimal Why shot captures and do some other tests.