-: Other WAN connections. 2 2
In this lesson, 3 3
we're going to cover some other WAN connection types, 4 4
specifically, SD-WAN and mGRE, 5 5
because they're a bit different 6 6
than the other WAN connections we already learned about. 7 7
First, let's talk about SD-WAN 8 8
or Software-Defined Wide Area Network. 9 9
An SD-WAN is a virtual WAN architecture 10 10
that allows enterprises to leverage any combination 11 11
of transport services 12 12
to securely connect users to their applications. 13 13
And SD-WAN is essentially a software-based WAN architecture 14 14
with all the control extracted from the underlying hardware. 15 15
So instead of configuring specific infrastructure 16 16
to handle application traffic, using something like MPLS, 17 17
you can actually manage an SD-WAN entirely in software, 18 18
plus layered over multiple types of network transport. 19 19
This means we can really use 20 20
any of the other WAN connections we may want to. 21 21
Things like MPLS, a cellular connection, a microwave link, 22 22
or a regular broadband internet service like a cable modem 23 23
in order to create a virtual Wide Area Network architecture 24 24
that we can then run our networks over. 25 25
To create an SD-WAN, 26 26
you can use a centralized control function 27 27
to securely and intelligently redirect the traffic 28 28
across the WAN. 29 29
Our traditional WANs, 30 30
which were never developed with the idea 31 31
of integrating cloud services into our enterprise networks, 32 32
can't do this. 33 33
Instead, SD-WANs enabled cloud-first enterprises 34 34
to deliver amazing quality experiences for their users. 35 35
Let's consider a company that has several branch offices 36 36
and one headquarters location. 37 37
In our traditional WAn architectures, 38 38
each branch office would likely be connected 39 39
back to the central office using a star topology. 40 40
This would allow the headquarters 41 41
to conduct advanced security on that traffic, 42 42
as it went from the branch offices to the headquarters, 43 43
and then out to the Internet. 44 44
This is great for security, sure, 45 45
but it really slows down the entire process 46 46
for the end users at those branch offices 47 47
and results in a poor user experience and lost productivity. 48 48
Now, unlike traditional architectures, 49 49
SD-WANs can solve this by using intelligence 50 50
to identify the network applications 51 51
being used by the end users 52 52
and routing that data across the WAN to the right places. 53 53
This allows your WAN environment 54 54
to be more dynamic and efficient 55 55
while providing improvements in visibility, performance, 56 56
and manageability of an enterprise WAN architecture 57 57
from a single centralized point. 58 58
Now, for the Network+ exam, 59 59
you don't need to know how to configure an SD-WAN, 60 60
but you do need to know when we might use it. 61 61
So if you're working at a large enterprise network 62 62
and you have lots of branch offices 63 63
and they're trying to move more and more into the cloud 64 64
using things IaaS and PaaS and SaaS, 65 65
then you may need to use an SD-WAN 66 66
to increase the performance for your end users 67 67
and reduce bottlenecks that were caused 68 68
by your traditional centralized WAN architecture. 69 69
Now, the second type of WAN connection 70 70
we need to discuss in this lesson 71 71
is mGRE or Multipoint Generic Routing Encapsulation. 72 72
mGRE is a protocol that can be used to enable one node 73 73
to communicate with many other nodes, 74 74
essentially creating a point-to-multipoint network. 75 75
So, where might you use mGRE? 76 76
Well, you could use mGRE 77 77
on your router at your headquarters, 78 78
and then you could support multiple other points 79 79
such as your branch offices connecting back to it. 80 80
With the older Generic Routing Encapsulation 81 81
or GRE protocols, 82 82
you are limited to point-to-point connections, 83 83
but with mGRE, you can do point-to-multipoint. 84 84
With those older GRE protocols, 85 85
we would basically use GRE to create a tunnel 86 86
and then create an IPSec tunnel within it to create a VPN 87 87
by having a dedicated router at the branch site 88 88
and another dedicated router at the headquarters. 89 89
But with mGRE, 90 90
we can instead have a single larger router 91 91
at our headquarters 92 92
that can support sending data from a single central router 93 93
to all the multiple branch sites at one time. 94 94
If you're going to use mGRE to sub this type of WAN connection, 95 95
it's usually going to be combined with DMVPN 96 96
or the Dynamic Multipoint VPN protocol. 97 97
This will give you better security. 98 98
This also allows you to create a dynamic VPN network 99 99
with multiple sites without having to pre-configure 100 100
the tunnel endpoint statically 101 101
like you would with a traditional VPN. 102 102
Again, for the exam, 103 103
it's just important to know what mGRE is 104 104
and what it's used for. 105 105
So, remember, mGRE is used to create tunnels 106 106
from one node to multiple nodes 107 107
and can be used as a form of WAN connection 108 108
within your network. 109 109
It's most often going to be used 110 110
with Dynamic Multipoint VPN or DMVPN 111 111
for enterprise networks with multiple smaller branch sites 112 112
that need to connect back to a centralized site. 113 113
It's a more traditional type of WAN architecture 114 114
than using something like SD-WAN.