Networking Fundamentals: Key Concepts and Troubleshooting
IPv4 Routing
In an IPv4 environment, what address is used by the router to send packets of data over a router interface to another? Destination network address
OSI Layer 3 Encapsulation
What addresses are added during encapsulation at OSI Layer 3? Source and destination IP addresses
Connectionless Systems
In a system without connection, which of the following is correct? The destination is not contacted before sending the packet
IP Packet Loop Prevention
What field of an IP packet prevents endless loops? Time to Live (TTL)
Router Network Layer
What portion of the network layer address does a router use to send packets? Destination network
Default Gateway
In the network shown, what address is the default gateway for host A in network 192.133.219.0? 192.133.219.1
Incorrect Default Gateway
If the default gateway is configured incorrectly on the host, what is the impact on communications? The host can communicate with other hosts on the local network, but cannot communicate with hosts on remote networks
Purpose of Default Gateway
What is the purpose of a default gateway? Identifies the device that allows computers on the local network to communicate with devices on other networks
Static Routing
What type of routing information is entered manually into the routing tables? Static
Router Actions When Destination Not Found
When the destination network is not listed in the routing table of a Cisco router, what are two possible actions that the router can take? The router sends the packet to the interface specified by the default route / The router discards the packet
Grouping Hosts into Networks
What are the key factors that should be considered when grouping hosts into a common network? Purpose / Geographical location / Ownership
Routing Table Entry Component
What is a component of an entry in the routing table? The address of the next hop
Network Security Devices
What intermediate device can be used to implement security between networks? Router / Firewall
Common Problems in Large Networks
What are three common problems that a large network presents? Security Issues / Host identification / Performance degradation
Broadcast Domains
In the network shown, assuming all devices are at factory default settings, how many broadcast domains are represented in the topology shown? 4
Route Operation Statements
What are three true statements about routes and their operation? If you connect to the destination network directly, the router forwards the packet to the destination host / If there is no route to the destination network and a default route is present, the packet is forwarded to the next-hop router / If the source host has a configured default gateway, it can forward the packet to a remote network through the route
Identifying Outbound Network Address
A network administrator attempts to resolve a connectivity problem and must determine the address that is used to forward network packets out of the network. If the command
netstat -ris used, is the manager able to identify the address that all hosts send packets with a destination outside the network? 10.10.10.6Resolving Broadcast Issues
A network administrator notices that there is much broadcast traffic on the network. What two steps can be taken by the network administrator to resolve this problem? Replace the switch with a router / Subnet the 192.168.0.0/24 network
Routing Topology Description
The network shown is in operation. Which two statements correctly describe the routing topology that is shown? Address 192.168.0.2 is the next hop used by R3 to route packets from network 10.0.0.0 to network 172.16.0.0 / 192.168.0.1 is the address of the next hop used by R2 to route packets from network 172.16.0.0 to network 192.168.12.0
Dynamic Routing Protocols
Which two are common characteristics associated with dynamic routing protocols? They provide routers with routing table updates / They consume bandwidth to exchange route information
Purpose of a Default Route
What purpose does a default route serve? A host uses a default route to transmit data to a host outside the local network when no other route to that destination exists