It is time.
It is time to implement the GRE tunnels.
Let's take a quick peek at our plan to confirm what it is.
That will help both us because I can remember what we agreed to,
and then we can walk through together--
the actual implementation of the GRE tunnels.
So this is our plan.
We'll use tunnel interface on R1 and R2.
We'll use their outside reachable addresses
for the beginning and the end of the tunnel respectively.
We'll include the network address space of 10.12.12
at the 24 route mask, and dot 1 over here and dot 2 over here.
And then we'll add EIGRP to the mix, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And then we'll add EIGRP to the mix,
and we'll include any interfaces that begin with 10.
That will capture the internal networks here.
It will also capture the tunnel interfaces
that we configure with 10 address space as well.
It's a party.
Let's start on R1s to a show IP interface brief.
Just to make sure I'm on the right device.
So gig 0 slash 3, the inside is 10.1,
and gig 0 slash 1 facing that public network is 15.1.1.1.
Fantastic.
So on R1, we'll create our tunnel interface.
Interface tunnel, and we are going to use the number of 0.
And we'll give it an IP address based WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And we'll give it an IP address based
on our plan, which is going to be
10.12.12.1 with a 24-bit mask.
Fantastic.
And it just said that it's up.
And we'll do a tunnel source.
Now for the tunnel source, we can have a couple options.
We could say the actual IP address here on 0
slash 1 of 15.1.1.1, or we could just point to the interface
and it knows what the IP address there is.
So in our case, let's just put in the IP
address of that interface to make it clear,
what we're talking about.
So the tunnel source will be 15.1.1.1 the tunnel destination WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So the tunnel source will be 15.1.1.1 the tunnel destination
is going to be the other side.
And I'll take a look at my notes real quick, which is 25.2.2.2.
So put that in there, and ask to do show run
for interface tunnel 0.
Fantastic.
And we'll repeat that with the correct IP
addresses on the other side.
So let's go to R2 and do the same thing.
So here in R2, config t, interface tunnel
0, IP address 10.12.12 with a 24-bit mask. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
0, IP address 10.12.12 with a 24-bit mask.
Let's say tunnel source is 25.2.2.2,
tunnel destination is 15.1.1.1.
Let's do a do show, run interface tunnel 0.
And I'm going to compare those two.
So here's R1 and here's R2.
That looks good.
And just as a test, if we do a show IP route and press
Enter for the network 10.12 because I WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Enter for the network 10.12 because I
am directly connected, so is the router on tunnel 0--
if we pinged another device on 10.12.12,
it would think, Oh, I need to use tunnel 0.
And that would cause it to encapsulate and shoot it
over to its good buddy, R1.
So let's do a quick ping to 10.12.12.1.
And that works.
That's a great sign.
Now the next one is a video do a video show IP route.
We currently-- if we're talking about the 10.1 network,
this is from R2's perspective, it's
going to use the default route, which WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
going to use the default route, which
isn't going to be forced through the tunnel interface.
So we need to add the routing to make that work.
So to do that based on our plan, we
decided we're going to use EIGRP autonomous system 1.
And we're going to include any interface of that
being with 10.
So let's do that next.
So config t router, EIGRP 1, and an auto-summary
even though I believe it's off these days.
And network 10 with a wildcard mass saying we're
only going to match on that first octet.
And we're done.
So IP EIGRP interface and we've got R2 interfaces-- gig 0/3 WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So IP EIGRP interface and we've got R2 interfaces-- gig 0/3
and also the tunnel interface 0.
Perfect.
Let's go do the same thing on R1.
So we're here on R1, router EIGRP 1.
[LAUGHTER]
Close, but no cigar.
And no auto-summary and network 10
with the wildcard mask, which basically
says any interface that starts with 10 anything are in.
And if we have a neighbors-- yeah there are.
That's a good sign.
The neighborship just came up.
And if we do a show IP route for EIGRP learned routes, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And if we do a show IP route for EIGRP learned routes,
this is beautiful.
R1 says, hey, to get to 10.2.0, I have an EIGRP learned route.
And there's the metric aka feasible distance.
And I'm going to use my egress interface of tunnel 0,
and the next hop address is 10.12.12.2.
Fantastic.
So we've made some good progress.
We planned out what we want to do for the GRE tunnel.
We also implemented it, and we added the routing protocols
we could have reachability over that tunnel.
And we verified that it works, but I'd WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And we verified that it works, but I'd
like to do one more thing if your game.
And that is this-- having a protocol capture
of packets before and after a process,
like before the GRE encapsulation
and after, that's going to help us understand the details
of what's really happening.
So in the next video, let's pause for a moment
and let's do some packet captures of traffic
before it hits the GRE tunnel, and then during the GRE tunnel,
and then after.
So we'll do all of that in the very next video.
I'll see you there in just a moment.
Meanwhile, I hope this has been informative for you.
And I'd like to thank you for viewing. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And I'd like to thank you for viewing.