In this video we're going to discuss generic writing encapsulation tunneling or GRV tunneling in its
most basic form a geography tunnel is a point to point tunnel that allows you to transport multiple
Hialeah protocols such as IP version for IP version 6 as well as older protocols such as IPX and others
across a point to point tunnel.
It's important to remember that GRV does not provide a theni cation an encryption.
It provides a point to point connection between two routers that emulates or looks like a point to point
tunnel or point to point serial link.
Another advantage of Geordie is the support for multicast routing protocols.
In the past what was often done is that GRV tunnels were encapsulated inside IP SEC tunnels for encryption
and authentication so surgery would provide a simple point to point link that emulates what looks like
a serial link but because it provides no encryption and no syndication that GRV tunnel would then be
put inside an IP CEQ tunnel to provide the encryption and offene cation.
Now before going any further I want to point out that you have access to some features of the VPN config
generator as part of your course.
One of the VPN config generator options is to set up a GOP tunnel.
The software allows you very easily to create the configuration required for a point to point Jeery
tunnel.
So as an example by clicking on the show result button the configuration is automatically generated
for two routers his router to and his router one you could simply copy and paste that configuration
into your routers to set up a GOP tunnel Jeery encapsulates other traffic inside a 20 byte IP header
and 4 byte GRV header the details of GRB can be found in RAFC 2 7 8 4.
And as you can see here this is for generic routing and kept isolation or GRV I wouldn't bore you going
through all the details but if you're interested have a look at the star of see but notice a payload
packet which is the data is sent by user PCs would being kept isolated inside the GOP tunnel using a
delivery header as well as GRV header.
You know Jean is Threet apology which I'm going to demonstrate in a moment.
That means that traffic sent from or one acting as PC one two or five acting as PC to in this typology
using keps elated by Rodda to as mentioned I'll show you this configuration in a moment and all.
Well so do washup captures that you can see the packets but in brief traffic sent by our one they sent
as normal and it frame's across the link.
But when it hits Rodda to it's encapsulated in a tunnel for transmission to Rotto for we're going to
build a tunnel from our two to our four and are three in this case is going to act as an internet router.
Or three is going to forward traffic based on the hour a header or delivery header.
Because the tunnel is established from two to four Azzurri only sees traffic going from our tu's IP
address to our foreign IP address.
It rots based on the hour ahead or delivery header and doesn't look at the traffic that originated from
our one.
Be careful however Jori doesn't encrypt.
So I'm going to demonstrate how you could run wireshark on this link and capture the internal traffic
that was sent from our one to our five.
So even though you encapsulating the traffic in a tunnel be aware that that tunnel is not encrypted.
So someone running wireshark or a hacking tool could see the internal traffic as sent in the payload
packet.
So the original data is encapsulated in the GOP header with a delivery header.
The route is on the Internet would route traffic based on the delivery header when traffic is received
by rodded to which is the source of the GOP tunnel in this case from Router one.
It's encapsulated injury sent across this tunnel to Rotto for which Dean capitulates the traffic and
sends it to ratify as the original packet as if this was a point to point link between Ratatouille and
Rato for example I've only got a single router being the Internet that remember you could have many
many devices here.
Forming the Internet
and the idea is that the tunnel is formed from one tunnel end point to another across many devices the
devices on the Internet rock based on the out ahead a router to is an example when receiving traffic
from router one will encapsulate those packets with injury headers.
Senators for reform will remove the headers and for the packet across to ratifiers as if there was a
point to point the link between two and wrote for the same thing will happen in the reverse.
Right a five will send a stented Ethan I-frame across this link to Rato for a form will encapsulate
the packet send it through the tunnel to rodded to which will then decapitate the packet and forward
the packet on to Roger one as if there was a point to point serial link between rodded to en route.
As mentioned all demonstrate the set up of this typology and we assume that this picture is GRV tunnel
from rhotic to Toronto.
It's simply a section that's established using the Jari protocol from Rodda to to rockfall but logically
it's as if you've got this extra serial interface on the roads which in our example will configure as
tunnels zero on both routers.