Vol 2 Part 4: Network Architecture Flashcards
What is a Campus LAN and explain how a Campus LAN is designed.
A Campus LAN refers to the LAN created to support devices in a building or in multiple buildings close together. Switches in each building are interconnected from floor to floor, and switches are used to interconnect multiple buildings.
A switch that forwards frame from itself to the user is known as what kind of switch in a Campus LAN?
Access Switch
What are the two types of switches that are connected to other switches in a campus LAN? Explain the differences between the two.
Distribution switches provide a path through which the access switches can forward traffic to each other, with each access switch needed to connect to at least one distribution switch.
A Core switch is utilized in a three tier campus design, and are expensive. A core layer is added, aggregating distribution switches in a very large Campus LAN. These core switches, while expensive, are extremely useful due to their high forwarding rates to handle larger volumes of traffic.
Within a two-tier Campus LAN, what are the 4 commonly seen network topologies? Explain each topology as well.
- Star- design with one central device connecting to several others. Not ideal, as the central device is a single point of failure.
- Full mesh- all network nodes are connected to each other.
- Partial Mesh- some network nodes are connected to each other.
- Combined topology design concepts into larger more complex design. A two-tier campus LAN is typically a hybrid design, as it has a star and partial mesh.
In a SOHO, the wireless device placed at the demarc is typically fulfilling what 3 roles all at once?
Firewall, switch, WAP
What is Metro Ethernet (MetroE)?
Ethernet from customer to service provider (SP). Metro Ethernet includes a variety of WAN services, and operates at layer 2. Typically, Metro Ethernet is fiber optic ethernet, with a set of switches used to connect an enterprise network to the SP. Customers typically connect to via a router or layer 3 switch.
What must be built throughout an area in a MetroE design in order to provide connectivity to the customer?
A point of presence
The physical link between the customer and SP in a MetroE design is called a BLANK.
An access link
In MetroE, everything that happens on an access link is called the BLANK.
user network interface
Ethernet Line Service (E-Line) is a MetroE topology where two sites are connected via an access link. It is the simplest of MetroE topologies. What is required in order for an E-Line topology to work with respect to where the routers are located?
The routers must be in the same subnet as each other. This allows them to use routing protocols to become neighbors and exchange routes, creating a point-to-point ethernet virtual circuit (EVC).
Ethernet Tree Service (E-Tree/Hub and Spoke) is a MetroE topology. Explain how this topology functions with respect to how the routers communicate?
A central site server, also known as the ROOT of the tree, is able to reach each remote LEAF site. These leaf sites can only send to the root. All leaf sites and root must be on the same subnet.
What is Multiprotocol Label Switching (MPLS)?
MPLS is a WAN service used to route packets between customer sites. MPLS VPNs are sued to route private network traffic from various customer sites to remote sites.
When using MPLS, edge routers are needed to add and remove the MPLS headers. What are the two types of edge routers used with MPLS, and explain the difference between the two.
Customer Edge (CE)- typically a router sitting at a customer site
Provider Edge (PE)- edge of the SPs network on the other end of the access link
MPLS operates on what layer?
Layer 3
Multiprotocol BGP (MPBGP) can be utilized in conjunction with MPLS. Why would we want to use MPBGP?
When you need to inject from one routing protocol to another (redistribution), MPBGP is extremely helpful, as you are able to, for example, take OSPF and inject the routes in MPBGP. This allows the Provider Edge (PE) router to become the next-hop router when needing to go across the WAN.
What does DSL use as the access link for services?
The telephone links supplied by the telephone company (telco)
What does the telco use with a Digital Subscriber Line (DSL) in order to differentiate between voice and data traffic on the same line?
a DSL access multiplexer (DSLAM)
What is meant by the term asymmetric speeds with respect to your upload and download speeds?
Your download speed is faster than your upload speed
What does cable internet use as the access link for services?
The cable tv cabling installed by your cable company
Wireless Internet is a general term for internet services delivered how?
Via radio waves. Services from a mobile phone or any device that uses wireless technology with an integrated wireless network interface card.
What are the different categories of wireless internet?
3G, 4G, LTE (part of 4G), 5G
Virtual Private Networks (VPN) establish a private tunnel on a public network. Explain each of the 4 primary security features of VPNs.
Confidentiality- prevents man in the middle attacks by preventing 3rd parties from reading data
Authentication- verification that the sender is legitimate and not an attacking device
Data integrity- verification that the packet has not been changed
Anti-Replay- prevents MITM from copying and later replaying packets sent by a legitimate user in order to pose as a legitimate user
VPN tunnels modify the original packet in order to add information to the packet so that the traffic is secure. Where in the packet does the VPN tunnel add this information?
In the packet’s header
Rather than creating a VPN tunnel everytime a user wants to access a private network, networks can be configured with what protocol? What does this protocol give us that a normal VPN client does not? Where is this protocol configured?
IPSEC. This allows a 24/7 private connection, with an ability to be added to and changed over time in order to improve security functions. IPSEC can be configured in a router or a firewall.
