CCNA 4 Chapter 5 V4.0 Answers
1. The following commands were entered on a router:
Router(config)# access-list 2 deny 172.16.5.24
Router(config)# access-list 2 permit any
The ACL is correctly applied to an interface. What can be concluded about this set of commands?
The wildcard mask 0.0.0.0 is assumed.
The access list statements are misconfigured.
All nodes on the 172.16.0.0 network will be denied access to other networks.
No traffic will be allowed to access any nodes or services on the 172.16.0.0 network.
2. Interface s0/0/0 already has an IP ACL applied inbound. What happens when the network administrator attempts to apply a second inbound IP ACL?
The second ACL is applied to the interface, replacing the first.
Both ACLs are applied to the interface.
The network administrator receives an error.
Only the first ACL remains applied to the interface.
CCNA 4 Chapter 4 V4.0 Answers
1. Which two statements are true regarding network security? (Choose two.)
Securing a network against internal threats is a lower priority because company employees represent a low security risk.
Both experienced hackers who are capable of writing their own exploit code and inexperienced individuals who download exploits from the Internet pose a serious threat to network security.
Assuming a company locates its web server outside the firewall and has adequate backups of the web server, no further security measures are needed to protect the web server because no harm can come from it being hacked.
Established network operating systems like UNIX and network protocols like TCP/IP can be used with their default settings because they have no inherent security weaknesses.
Protecting network devices from physical damage caused by water or electricity is a necessary part of the security policy.
2. Which two statements are true about network attacks? (Choose two.)
Strong network passwords mitigate most DoS attacks.
Worms require human interaction to spread, viruses do not.
Reconnaissance attacks are always electronic in nature, such as ping sweeps or port scans.
A brute-force attack searches to try every possible password from a combination of characters.
Devices in the DMZ should not be fully trusted by internal devices, and communication between the DMZ and internal devices should be authenticated to prevent attacks such as port redirection.
CCNA 4 Chapter 3 V4.0 Answers
1. Which three actions might a Frame Relay switch perform when it detects an excessive build-up of frames in its queue? (Choose three.)
puts a hold on accepting frames in excess of the CIR
drops frames from the queue that have the DE bit set
reduces the number of frames it sends over the link
re-negotiates flow control with the connected device
sets the FECN bit on all frames it receives on the congested link
sets the BECN bit on all frames it places on the congested link
2. Which best describes the benefit of using Frame Relay as opposed to a leased line or ISDN service?
Customers can define their virtual circuit needs in far greater combinations, with increments as small as 64 kbps.
Customers pay for an end-to-end connection that includes the local loop and the network link.
Customers only pay for the local loop and the bandwidth they purchase from the network provider.
Connecting new sites requires new lower cost circuit installations when compared to ISDN dialup costs or adding additional hardware for leased service.
CCNA 4 Chapter 2 V4.0 Answers
1.
Refer to the exhibit. Router R1, the DCE device, has just been configured for PPP encapsulation with authentication. What series of commands will allow another router, the DTE device, to communicate over its serial 0/0/0 interface to router R1?
Router(config)# hostname R3
R3(config)# username R1 password Cisco
R3(config)# interface Serial 0/0/0
R3(config-if)# encapsulation ppp
R3(config-if)# ip address 172.16.3.3 255.255.255.0
R3(config-if)# ppp authentication chap
Router(config)# hostname R3
R3(config)# username R3 password Cisco
R3(config)# interface Serial 0/0/0
R3(config-if)# encapsulation ppp
R3(config-if)# ip address 172.16.3.3 255.255.255.0
R3(config-if)# ppp authentication chap
Router (config)# username Router password Cisco
Router (config)# interface Serial 0/0/0
Router (config-if)# clockrate 64000
Router (config-if)# encapsulation ppp
Router (config-if)# ip address 172.16.3.1 255.255.255.0
Router config-if)# ppp authentication chap
Router (config)# username R1 password Cisco
Router config)# interface Serial 0/0/0
Router (config-if)# clockrate 64000
Router config-if)# encapsulation ppp
Router (config-if)# ip address 172.16.3.1 255.255.255.0
Router (config-if)# ppp authentication chap
2. Which serial communications DTE/DCE interface standard is used to provide high-speed connectivity of up to 52 Mbps between LANs and is found on many high-end Cisco routers?
EIA/TIA 232 (RS-232)
EIA/TIA 422 (RS-422)
EIA/TIA 423 (RS-423)
EIA/TIA-612/613 (HSSI)
ITU V.35
CCNA 4 Chapter 1 V4.0 Answers
1. Which statement is true about the differences between a WAN and a LAN?
WANs generally support higher bandwidth than LANs support.
A WAN link typically traverses shorter geographic distances than a LAN link traverses.
A WAN often relies on the services of carriers, such as telephone or cable companies, but a LAN does not.
All WAN implementations generally use the same Layer 2 protocol but there are many accepted LAN Layer 2 protocols in use.
2. A U.S. company requires a WAN connection used only to transfer sales data from individual stores to the home office. All transfers will occur after business hours. The required bandwidth for this connection is estimated to be less than 38 kbps. Which type of connection requires the least investment for this company?
ATM
ISDN
analog dialup
T1 Leased Line