CCNA review Flashcards
1
Q
Describe how dynamic NAT works
A
- Maps multiple local to global addresses
- Takes global addresses from pool on first-come, first-serve
2
Q
Explain why syslog is used.
A
- Enables you to gather logging info for monitoring and troubleshooting
- To select the type of logging info that is captured
- To specify the destinations of captured syslog messages
3
Q
Explain why SNMP is used, how it works, and its versions.
A
- It allows an NMS to get environment and performance parameters of a network device.
- It defines how SNMP managers and agents exchange management info.
- It’s versions are SNMP manager, SNMP agent, and MIB
4
Q
Explain VPNs.
A
- They secure communication across an untrusted network.
- Are logical networks, independent of physical architecture
- Are independent of IP addressing and routing schemes. (noncryptographic)
- They secure confidentiality, message integrity, and origin authentication (cryptog)
- Classified according to deployment mode and underlying technology
- They provide cost savings, scalability, security, and compatibility with broadband tech
5
Q
Explain the basic concept of switching
A
- switch builds MAC address table that matches the destination MAC address with port used to connect to a node
- MAC address in frame header is compared to list of addresses in MAC table
- Switch uses MAC addresses as they decide whether to filter, send, or flood the frames
- When destination MAC address of received unicast frame resides on same switch port as source, switch drops the frame
6
Q
Describe how switches operate and build CAM table
A
- Switches perform learning and forwarding actions
- Create and maintain MAC address table by using source MAC addresses of incoming frames an the port number through which the frame entered the switch
7
Q
Describe reserved IPv4 addresses.
A
- They can’t be assigned to individual devices on a network.
- They include a network address used to identify the network itself and a broadcast address.
- Ones with binary zeros in all host bit positions is reserved for the network address.
- Network address, Local broadcast address, Directed broadcast address, Local Loopback, Autoconfiguration Ipv4, Ipv4 for Documentation, and All Zeros
8
Q
Describe the IPv6 unicast addresses
A
- Global Unicast (2000::/3): Assigned by IANA and used on public networks. Are equal to Ipv4 global addresses.
- Link Local (fe80::/10): Auto configured on interface, the scope is only on physical link, and is required.
- Unique Local (fc00::/7): Used for local comms.
- Used in one-to-one context.
- Are assigned to each node.
9
Q
List the characteristics and features of switches.
A
- Dedicated communication between devices
- Multiple simultaneous conversations.
- Full-duplex communication
- Media-rate adaptation.
- High port density
- Large frame buffers.
- Port speed
- Fast internal switching
- Low per-port cost
10
Q
Identify the components of a LAN
A
- Hosts
- Interconnections (NICs and Network media)
- Network Devices (Ethernet switches, routers, and APs)
- Protocols
11
Q
Describe the issues in poorly designed LANs
A
- Has increased support costs
- Reduced service availability
- Limited support for new apps and solutions
12
Q
Describe the enterprise network design
A
- Tiered network design models use a hierarchical design
- Each element in hierarchy has a specific set of functions and services that it offers a specific role to play in the design
- Allows you to better understand the features that may be needed
- Can be upgrades as tech changes
- Makes it easy to discuss and learn about a particular part of the solution
- The modularity is based on designing in layers
- Includes access, distribution, and core layers
13
Q
Describe the options for inter-VLAN routing
A
OPTION 1: Router with separate interface for each VLAN::: Facilitates the routing process in a multi-VLAN environment. When using a router to facilitate inter-VLAN routing, router interfaces are connected to switch interfaces that are in separate VLANs. This option isn’t scalable and you can run out of interfaces.
OPTION 2: Router on a stick::: A single physical interface routes traffic among multiple VLANs on a network.
14
Q
Describe the features of OSPF
A
- Uses two-layer hierarchy that has two primary elements (AS and Area)
- Fast convergence
- Ability to scale larger than networks
15
Q
Explain how OSPF decides what is the best path through the network
A
-As OSPF routers accumulate link-state info, they use the SPF algorithm to calculate the shortest path to each network.
16
Q
Explain OSPF neighbor states
A
Down State: No info exchanged between routers yet. Router sends hello packet
INIT State: All routers running OSPF get the hello packet from first router and add the router to their list of neighbors
Two-way State: Each router that got the hello packet sends unicast reply hello packet to the first router with its corresponding info. Neighboring field in packet lists all neighboring routers, including first router.
17
Q
Describe the process of loading Cisco IOS configuration files
A
- Router starts
- If there’s an existing startup config file in NVRAM, it’s executed.
- If there isn’t, the device begins auto install or enters setup utility
- Router loads and executes the config from NVRAM.
- If there’s no config in NVRAM, it prompts for initial config dialog
- If startup config file isn’t in NVRAM, router may search TFTP server
- If router detects that it has an active link, it sends broadcast searching for a config file across the active link
18
Q
Describe how to configure static routes
A
- Specify an IPv4 destination network
- Use the IPv4 address of the next-hop router
- Or use the outbound interface of the local router
19
Q
Describe how to verify IPv6 static routes
A
- [show ip route] command
- static route includes network address, subnet mask in prefix form, and ipv4 address of the next=hop server or exit interface
- Denoted with the code “S” in the routing table.
20
Q
Describe the concept of HSRP
A
- Facilitates transparent failover of the first-hop IP device (default gateway)
- When using HSRP, you config the host with the HRSP virtual IP address as its default gateway instead of using the IP address of the router.
- Defines a standby group of routers, while one router is designated as the active router
- Provides gateway redundancy by sharing IP and MAC addresses between redundant gateways.
- Consists of virtual IP and MAC addresses that the two routers that belong to the same HSRP group share between each other.
21
Q
Explain the basic difference between TCP and UDP
A
TCP can ensure that data is delivered, while UDP doesn’t ensure delivery.
22
Q
Explain the characteristics of TCP in brief
A
- Operates at the transport layer of the TCP/IP stack (OSI layer 4)
- Provides app access to the Internet layer (OSI Layer3), where app date is routed from the source IP host to the destination IP host.
- Is connection-oriented and requires that network devices set up connection to exchange data.
- Provides checksum in TCP segment to verify that header info isn’t corrupt
- Establishes two connections between source and destination which operate in full-duplex mode.
- Segments are numbered and sequenced so destination can reorder segments
- Provides mechanisms for flow control
23
Q
Define the function of DNS
A
-Provides efficient way to convert human-readable names of IP end systems into machine readable IP addresses needed for routing
24
Q
Describe the functions of a router
A
Path Determination:
- When router gets packet, it examines destination IP address in packet and looks for best match between the destination address and the net address in routing table.
- Matching entry means destination is directly connected to the router or it can be reached via another router.
- This router is a next-hop router and is on the path to final destination.
- If there’s no matching entry, router sends packet to default route.
Packet Forwarding:
- Another router chooses right path for packet, it forwards it through interface toward destination network
- When forwarding, routers perform encap following the OSI L2 protocol at exit interface.
- If router needs to forward the packet out of serial interface, router will encap from according to L2 protocol used on serial link
25
Describe the components of a routing table
- Directly connected networks
- Dynamic routes
- Static routes
- Default routes
26
Identify common switched network media issues
- Damaged wiring
- New EMI sources introduced
- Traffic patterns change
- New equipment installed
27
Identify common access port issues
Duplex and speed related issues:
- One end full and other end half is BAD
- One end full and other end autonegotiation is BAD
- One end half and other end autonegotiation is BAD
- Autonegotiation on both ends is BAD
28
Identify common network components by function
Endpoints: End user devices
Intermediary devices: Interconnect devices/networks (switches, routers, APs, WLCs, Firewalls, IPS, Management services)
29
Define the purpose and function of trunking
- Allows switches to pass frames from multiple VLANs over a single physical connection
- Each frame has a tag that specifies the VLAN it belongs to
- Receiving device forwards the frames to the corresponding VLAN based on the tag info
30
Identify physical installation requirements
- Proper installation method
| - Network cables that provide connectivity to LAN
31
Connect to a switch console port
- You need an RJ-45 to DB-9 cable
- You need a USB to DB-9 adapter
- USB A, USB mini B, or USB C to RJ-45 console cable
-You need a PC or equivalent with serial/USB port.
-An OS
-Terminal emulator software configured with:
Speed: 9600 bps
Data bits: 8
Parity: None
Stop bit: 1
Flow Control: None
32
Describe the Common Programmability Protocols and Methods in the Model-driven Programmability Stack
-Model-driven Programmability allows you to automate the config and state info of network devices running on different Cisco OS, or even use orchestrators to provide end-to-end service delivery.
33
Which three types of booting are supported on servers?
- Internal storage
- SAN
- LAN
34
The Open Shortest Path First (OSPF) protocol calculates multiple possible routes for the same destination network. Which parameter is used to decide which route will be offered to the routing table?
-Metric
35
Refer to the exhibit. Which menu item should you select to configure a pre-shared key for a wireless network?
-WLANs
36
A company needs to implement a secure VPN solution using IPsec. Which protocol and encryption algorithm should be used to guarantee VPN confidentiality?
ESP protocol with the 3DES encryption algorithm
37
In the lab network, which SSHACCESS access list implementation would correctly limit remote access to only SSH connections from PC2?
-Inbound direction on the vty lines on R1
38
Which instruction should you use to parse a JSON string in Python?
-json.loads(input)
39
Which language is used in the Cisco Network Services Orchestrator (NSO) to describe the network service intent?
-YANG
40
Which two statements about the Dynamic Multipoint Virtual Private Network (DMVPN) are true?
- DMVPN creates hub-to-spoke tunnels
| - DMVPN creates spoke-to-spoke tunnels
41
Which type of cable is typically used to connect a core switch with a data center switch, where bandwidth higher than 40 Gbps and low cost are required?
-multimode fiber
42
Which two types of cables can be used to connect to the console port of a Cisco router?
- Rollover
| - USB
