SANS 401 GSEC Exam 2023 Graded A
Network Topology
The Physical/Logical shape of a network
Logical Topology
Gives the description for the physical layout, shows VLAN's and where they are placed
on the physical topology
Trunk Port
Connects packets that travel to all VLAN's on a switch
Baseband Systems
Transmits one signal on the medium (fiber, copper, etc)
Broadband
Form of multiplexing to join multiple signals on a medium
Ethernet
Designed as baseband system that can be used in multiplexing
CSMA/CD
Carrier Sense Multiple Access/ Collision Detection
Unicast
Broadcast for a single device
Multicast
Broadcast for a specific group or multiple devices
Broadcast
Message for everyone to receive and process
Hub
Broadcasts packets to every single port
Switch
Broadcasts packets to device found on a singular port
Content Addressable Memory (CAM)
Is a table that contains the MAC address and port associated to that MAC Address
Virtual LAN (VLAN)
Splitting a switch in which certain ports can only talk to certain ports (Segment networks
within a switch)
Multiprotocol Label Switching (MPLS)
A different way of switching packets that can be used on a dedicated line
802.1x
Network Access Control that is a layer 2 authentication (Credentialed Question of 2FA)
A security appliance should be set in place when
There is a change in trust level in the network
Protocol
is an agreement or rules of engagement for how computer networks communicate
OSI Protocol Stack (7)
Layer 7) Application
Layer 6) Presentation
Layer 5) Session
Layer 4) Transport
Layer 3) Network
, Layer 2) Data Link
Layer 1) Physical
Application Layer 7 OSI Stack
Browsers, FTP, HTTP, SCP
Presentation Layer 6 OSI Stack
Makes data presentable to the application or user (ASCII)
Session Layer 5 OSI Stack
Handles the establishment/maintenance of connections between systems
Transport Layer 4 OSI Stack
Determines that application the packet should be sent to through port numbers (Web on
80,443)
Network Layer 3 OSI Stack
Moving packets from one network to another network, uses logical addressing instead
of physical addressing
Data Link Layer 2 OSI Stack
Takes a packet and frames it suitable for transmission
Physical Layer 1 OSI Stack
Network cable, electromagnetic radiation
TCP/IP Protocol Stack (4)
Layer 4) Application
Layer 3) Transport (TCP/UDP)
Layer 2) Internet (IP)
Layer 1) Network
Network Address in: 10.1.2.0/24 Subnet
10.1.2.0
Broadcast Address in: 10.1.2.0/24 Subnet
10.1.2.255
Class A CIDR Addressing (Mask, IP Range)
N.H.H.H, 255.0.0.0 - 1-127
10.0.0.0/8
16.7 Million IP's
Class B CIDR Addressing (Mask, IP Range)
N.N.H.H, 255.255.0.0 - 128-191
172.16.0.0/16
65,536 IP's
Class C CIDR Addressing (Mask, IP Range)
N.N.N.H, 255.255.255.0 - 192-223
192.168.1.0/24
256 IP's
Address that broadcasts to current network
255.255.255.255
ARP (Address Resolution Protocol)
Required to go from Layer 2 to 3, broadcasts to a network querying for an IP Address,
once found, sends it back to requesting MAC
DNS (Domain Name System)
Name to an IP Address (TCP/UDP 53)
Network Topology
The Physical/Logical shape of a network
Logical Topology
Gives the description for the physical layout, shows VLAN's and where they are placed
on the physical topology
Trunk Port
Connects packets that travel to all VLAN's on a switch
Baseband Systems
Transmits one signal on the medium (fiber, copper, etc)
Broadband
Form of multiplexing to join multiple signals on a medium
Ethernet
Designed as baseband system that can be used in multiplexing
CSMA/CD
Carrier Sense Multiple Access/ Collision Detection
Unicast
Broadcast for a single device
Multicast
Broadcast for a specific group or multiple devices
Broadcast
Message for everyone to receive and process
Hub
Broadcasts packets to every single port
Switch
Broadcasts packets to device found on a singular port
Content Addressable Memory (CAM)
Is a table that contains the MAC address and port associated to that MAC Address
Virtual LAN (VLAN)
Splitting a switch in which certain ports can only talk to certain ports (Segment networks
within a switch)
Multiprotocol Label Switching (MPLS)
A different way of switching packets that can be used on a dedicated line
802.1x
Network Access Control that is a layer 2 authentication (Credentialed Question of 2FA)
A security appliance should be set in place when
There is a change in trust level in the network
Protocol
is an agreement or rules of engagement for how computer networks communicate
OSI Protocol Stack (7)
Layer 7) Application
Layer 6) Presentation
Layer 5) Session
Layer 4) Transport
Layer 3) Network
, Layer 2) Data Link
Layer 1) Physical
Application Layer 7 OSI Stack
Browsers, FTP, HTTP, SCP
Presentation Layer 6 OSI Stack
Makes data presentable to the application or user (ASCII)
Session Layer 5 OSI Stack
Handles the establishment/maintenance of connections between systems
Transport Layer 4 OSI Stack
Determines that application the packet should be sent to through port numbers (Web on
80,443)
Network Layer 3 OSI Stack
Moving packets from one network to another network, uses logical addressing instead
of physical addressing
Data Link Layer 2 OSI Stack
Takes a packet and frames it suitable for transmission
Physical Layer 1 OSI Stack
Network cable, electromagnetic radiation
TCP/IP Protocol Stack (4)
Layer 4) Application
Layer 3) Transport (TCP/UDP)
Layer 2) Internet (IP)
Layer 1) Network
Network Address in: 10.1.2.0/24 Subnet
10.1.2.0
Broadcast Address in: 10.1.2.0/24 Subnet
10.1.2.255
Class A CIDR Addressing (Mask, IP Range)
N.H.H.H, 255.0.0.0 - 1-127
10.0.0.0/8
16.7 Million IP's
Class B CIDR Addressing (Mask, IP Range)
N.N.H.H, 255.255.0.0 - 128-191
172.16.0.0/16
65,536 IP's
Class C CIDR Addressing (Mask, IP Range)
N.N.N.H, 255.255.255.0 - 192-223
192.168.1.0/24
256 IP's
Address that broadcasts to current network
255.255.255.255
ARP (Address Resolution Protocol)
Required to go from Layer 2 to 3, broadcasts to a network querying for an IP Address,
once found, sends it back to requesting MAC
DNS (Domain Name System)
Name to an IP Address (TCP/UDP 53)
