1What is the purpose of an IP address?
It is a logical address used for end-to-end delivery across networks.
2What is the purpose of a MAC address?
It is a physical address used for delivery on a local link.
3What protocol maps IPv4 addresses to MAC addresses?
ARP (Address Resolution Protocol)
4How does ARP work?
A device broadcasts a request asking who has an IP, and the owner replies with its MAC.
5Where are resolved MAC addresses stored?
In the ARP cache (ARP table)
6Which command displays the ARP table?
arp -a
7Which command deletes ARP table entries?
arp -d
8What happens when two devices are on the same network?
The source device ARPs directly for the destination’s MAC.
9What happens when devices are on different networks?
The source device ARPs for the default gateway’s MAC address.
10Which address changes at each router hop?
The MAC address
11Which address stays constant across the entire path?
The IP address
12What does IPv6 use instead of ARP?
Neighbor Discovery Protocol (NDP)
13What message does NDP use to request a MAC address?
Neighbor Solicitation
14What message does NDP use to reply with a MAC address?
Neighbor Advertisement
15What are two risks of ARP?
Network overhead and ARP spoofing/poisoning
Routers & Switches
16What is the main purpose of a router?
To forward packets between different networks based on the destination IP address
17Which OSI layer does a router operate on?
Layer 3 (Network layer)
18What are the three main access methods for routers?
Console cable, Telnet, SSH
19What is the prompt symbol for User EXEC mode?
>
20What is the prompt symbol for Privileged EXEC mode?
#
21What is the prompt for Global Configuration mode?
(config)#
22Which command sets the router hostname?
hostname
23Which command secures privileged EXEC mode?
enable secret
24Which command configures console access password?
line console 0 → password → login
25Which command configures VTY (Telnet/SSH) access password?
line vty 0 4 → password → login
26Which command encrypts all plaintext passwords?
service password-encryption
27Which command assigns an IP address to an interface?
ip address
28Which command activates a router interface?
no shutdown
29Which command shows interface status and IP configuration?
show ip interface brief
30Which command tests network connectivity?
ping
31Which command saves the running configuration to startup-config?
copy running-config startup-config
32What must host PCs configure to reach other networks?
A default gateway
33What is the default gateway for hosts in a subnet?
The router’s IP address on that subnet interface
34Which OSI layer does a switch operate on?
Layer 2 (Data Link)
35What address type does a switch use to forward frames?
MAC address
36What must be configured for remote switch management?
An IP address on a switch Virtual Interface (SVI) and a default gateway
37Which command assigns an IP address to VLAN 1?
ip address
38Which command enables the VLAN interface?
no shutdown
39Which command sets the switch default gateway?
ip default-gateway
40Which command shows interface status and IP information?
show ip interface brief
41Which command displays learned MAC addresses?
show mac address-table
42By default, which VLAN are switch ports in?
VLAN 1
43What type of switch port connects to end devices?
Access port
44What type of switch port carries multiple VLANs?
Trunk port
45What does VLAN stand for?
Virtual Local Area Network
46What is the purpose of VLANs?
To segment a switch into multiple logical networks and control broadcast domains
47What is routing?
The process of forwarding packets from one network to another
48What does a router use to decide where to send packets?
A routing table
49What are the two main types of routing?
Static routing and dynamic routing
50What is static routing?
Manually configured routes created by an administrator
51What is the command format for a static route?
ip route
52What is a default route used for?
As a catch-all route when no other entry in the routing table matches
53What is the command format for a default route?
ip route 0.0.0.0 0.0.0.0
54What is the symbol for a directly connected network in the routing table?
C
55What is the symbol for a static route in the routing table?
S
56What is the symbol for a default static route in the routing table?
S*
57Which command shows the routing table?
show ip route
58Which command shows the path packets take?
tracert
59In what type of networks is static routing most useful?
Small, predictable networks
60What are two advantages of static routing?
Simple and predictable, no CPU overhead
61What are two disadvantages of static routing?
Not scalable for large networks, manual reconfiguration needed if topology changes
62What is the main difference between static and dynamic routing?
Static routing is manually configured, while dynamic routing uses protocols to learn routes automatically.
63Why use dynamic routing instead of static routing?
It adapts to network changes automatically and scales better.
64What is one disadvantage of dynamic routing?
Consumes more CPU and memory resources.
65Routers share routing tables with neighbors using hop count as metric.
What is a Distance Vector protocol?
66Give an example of a Distance Vector protocol.
RIP
67What is a Link-State protocol?
Routers advertise link states and build a complete map using cost as a metric.
68Give an example of a Link-State protocol.
OSPF
69What is a Hybrid routing protocol?
Combines features of distance vector and link-state.
70Give an example of a Hybrid routing protocol.
EIGRP
71What is Administrative Distance (AD)?
A value ranking trustworthiness of routes (lower is better).
72What is the AD of a directly connected network?
0
73What is the AD of a static route?
1
74What is the AD of EIGRP?
90
75What is the AD of OSPF?
110
76What is the AD of RIP?
120
77What metric does RIP use?
Hop count
78What metric does OSPF use?
Cost, based on bandwidth
79What metrics can EIGRP use?
Delay, load, reliability, and bandwidth
80What is an ACL?
A list of rules on a router interface that permits or denies traffic.
81What are the two main types of ACLs?
Standard ACLs and Extended ACLs.
82What do Standard ACLs filter by?
Source IP address only
83Where should Standard ACLs be applied?
Closest to the destination
84What is the number range for Standard ACLs?
1–99 and 1300–1999
85What do Extended ACLs filter by?
Source/destination IP, protocol, and port
86Where should Extended ACLs be applied?
Closest to the source
87What is the number range for Extended ACLs?
100–199 and 2000–2699
88How are ACL rules processed?
Top to bottom; first match applies
89What happens if no ACL rule matches?
Implicit deny all
90What does a wildcard mask do in ACLs?
Specifies IP ranges (0 = match, 1 = don’t care)
91What does the wildcard mask 0.0.0.255 mean?
All hosts in a /24 network
92What does the keyword "host" in an ACL mean?
Exactly one host IP
93Which command shows the ACL rules on a router?
show access-lists
94Which command shows which ACLs are applied to interfaces?
show run
95What does DHCP stand for?
Dynamic Host Configuration Protocol
96What is the main purpose of DHCP?
To automatically assign IP addresses and network info to clients
97What settings can DHCP provide?
IP address, subnet mask, default gateway, DNS server
98What does DORA stand for in DHCP?
Discover, Offer, Request, Acknowledge
99What is a DHCP lease?
Period of time an IP address is assigned to a client
100What happens when a DHCP lease expires?
The client must renew the lease
101What command excludes reserved addresses from a DHCP pool?
ip dhcp excluded-address
102Why exclude addresses?
To reserve them for devices like servers or routers
103What command creates a DHCP pool?
ip dhcp pool
104What command sets the default gateway in a DHCP pool?
default-router
105What command sets the DNS server in a DHCP pool?
dns-server
106What is DHCP relay used for?
To forward DHCP requests across networks
107What command enables DHCP relay?
ip helper-address
108Which command shows current DHCP bindings?
show ip dhcp binding
109Which PC command requests a new lease?
ipconfig enew
Security
110What does the CIA triad stand for?
Confidentiality, Integrity, Availability
111What is a reconnaissance attack?
Gathering info (ping sweeps, port scans)
112What is an access attack?
Attempt to gain unauthorized access
113What is a DoS attack?
Flooding resources to make services unavailable
114What is a DDoS attack?
A DoS attack launched from multiple devices
115What is a computer virus?
Malware that attaches to files and spreads when executed
116What is a worm?
Self-replicating malware that spreads without user action
117What is a Trojan Horse?
Malware disguised as legitimate software
118What is ransomware?
Malware that encrypts files and demands payment
119What is phishing?
Fake emails/messages pretending to be trusted sources
120What does AAA stand for?
Authentication, Authorization, Accounting
121What is the role of a firewall?
To filter network traffic
122What is IDS/IPS?
Intrusion Detection/Prevention Systems
123What is a VPN?
Virtual Private Network that encrypts traffic
124Which secure protocol should replace Telnet?
SSH
125Which wireless security standards should be used?
WPA2 or WPA3
126Why is WEP not recommended?
It is outdated and easily cracked