1.3 Pt 3

Question 1

Packet/Traffic shaping

Answer 1

Set important applications to have higher priorities than other apps in router, firewall, or switch.

QoS (Quality of Service)

CoS (Class of Service), Layer 2, performed in the frame header in an 802.1q trunk, between switches in internal network

DiffServ (Differentiated Services), Layer 3, QOS bits are enabled in the IPv4 header, external to the application, applied by the router

Question 2

NAT

Answer 2

Router changes source IP from a private address to its routable public IP address on outgoing traffic.

Also changes destination IP from a public address to the correct private address on incoming traffic.

Question 3

PAT (NAT overload)

Answer 3

Same as NAT but when multiple devices are present.

Client adds random port to its source IP, router records that in its NAT table, router adds random port to the public IP when it translates.

Incoming traffic’s dest IP has the routers port which the router then translates to the private IP/Port the client sent out.

Question 4

Port Forwarding

Answer 4

Allow devices outside your network access to an internal private IP.

External IP/port maps to an internal IP/port

Question 5

Access Control List (ACL)

Answer 5

Used to allow or deny traffic

Defined on incoming, outgoing, or both

Can evaluate on many criteria (src/dest IPs, ports, ICMP), called tuples

What happens when traffic matches criteria?
Logical path from top down

Firewallls can be considered ACL
Implicit DENY rule at the bottom

Question 6

Circuit Switching

Answer 6

Circuit is established between endpoints before data passes
No one else can use the connection and it’s always there

POTS (plain old telephone service)
PSTN (public switched telephone network)

T1/T3/E1/E3 are circuit switched

ISDN modem

Question 7

Packet Switching

Answer 7

Data is grouped into packets and sent

Voice, data, video
Media is usually shared
Supports QOS, one user can have more bandwidth

SONET, ATM, DSL, Frame Relay, MPLS, Cable, Satellite, Wireless

Question 8

SDN (Software Defined Networking)

Answer 8

Network devices have two functional planes
Control-administrative/servicing
Data-transfers/forwards data

Programmable, configuration is different than forwarding

Changes can be made dynamically

Centrally managed, orchestrated (no human intervention), vendor neutral

Question 9

Distributed Switching

Answer 9

A virtual network distributed across all physical platforms

When a VM moves the network doesn’t change

Group individual servers on virtual platforms into separate VLANs