Up to date Cisco 100-105 practice test

Answer: A,C,D 

Explanation: 

During Transfer of data, a high speed computer is generating data traffic a lot faster than the network device can handle in transferring to destination, so single gateway or destination device cannot handle much amount of traffic that is called "Congestion". 

Buffering The Technie is used to control the data transfer when we have congestion, when a network device receive a data it stores in memory section and then transfer to next destination this process called "Buffering". Windowing Whereas Windowing is used for flow control by the Transport layer. Say the sender device is sending segments and the receiver device can accommodate only a fixed number of segments before it can accept more, the two devices negotiate the window size during the connection setup. This is done so that the sending device doesn't overflow the receiving device's buffer. Also the receiving device can send a single acknowledgement for the segments it has received instead of sending an acknowledgement after every segment received. Also, this window size is dynamic meaning, the devices can negotiate and change the window size in the middle of a session. So if initially the window size is three and the receiving device thinks that it can accept more number of segments in its buffer it can negotiate with the sending device and it increases it to say 5 for example. Windowing is used only by TCP since UDP doesn't use or allow flow control. 

Reference: http://www.info-it.net/cisco/ccna/exam-tips/flow-control.php 

Answer: B 

Explanation: 

A switch uses a separate collision domain for each port, and each VLAN is a separate broadcast domain. 

Topic 3, Routing Fundamentals 

Answer: A,D 

Explanation: 

The source and destination addresses are on the same network therefore, a default gateway is not necessary for communication between these two addresses. 

Answer: A,C,E 

Explanation: 

The given IP addresses of areas 1 and 3 along with network masks of /24 cannot accommodate 500 users so are inadequate, while the area 2 is having over capacity so its network mask can be reduced to /25 to accommodate the only 60 users it has. 

Answer: A 

Explanation: By default, each IP address assigned by a DHCP Server comes with a one-day lease, which is the amount of time that the address is valid. To change the lease value for an IP address, use the following command in DHCP pool configuration mode: 

Answer: B 

Explanation: You can use the passive-interface command in order to control the advertisement of routing information. The command enables the suppression of routing updates over some interfaces while it allows updates to be exchanged normally over other interfaces. With most routing protocols, the passive-interface command restricts outgoing advertisements only. But, when used with Enhanced Interior Gateway Routing Protocol (EIGRP), the effect is slightly different. This document demonstrates that use of the passive-interface command in EIGRP suppresses the exchange of hello packets between two routers, which results in the loss of their neighbor relationship. This stops not only routing updates from being advertised, but it also suppresses incoming routing updates. This document also discusses the configuration required in order to allow the suppression of outgoing routing updates, while it also allows incoming routing updates to be learned normally from the neighbor. 

Answer: D 

Explanation: 

The default AD for a static route is 1. To change this, configure a different value to be used as the AD at the very end of the “ip route” statement. 

Answer: C 

Explanation: 

Message Authentication Code (MAC) can shield your network from spoofing attacks. Spoofing, also known as masquerading, is a popular trick in which an attacker intercepts a network packet, replaces the source address of the packets header with the address of the authorized host, and reinserts fake information which is sent to the receiver. This type of attack involves modifying packet contents. MAC can prevent this type of attack and ensure data integrity by ensuring that no data has changed. MAC also protects against frequency analysis, sequence manipulation, and ciphertext-only attacks. MAC is a secure message digest that requires a secret key shared by the sender and receiver, making it impossible for sniffers to change both the data and the MAC as the receiver can detect the changes. A denial-of-service (DoS) attack floods the target system with unwanted requests, causing the loss of service to users. One form of this attack generates a flood of packets requesting a TCP connection with the target, tying up all resources and making the target unable to service other requests. MAC does not prevent DoS attacks. Stateful packet filtering is the most common defense against a DoS attack. A Distributed Denial of Service attack (DDoS) occurs when multiple systems are used to flood the network and tax the resources of the target system. Various intrusion detection systems, utilizing stateful packet filtering, can protect against DDoS attacks. In a SYN flood attack, the attacker floods the target with spoofed IP packets and causes it to either freeze or crash. A SYN flood attack is a type of denial of service attack that exploits the buffers of a device that accept incoming connections and therefore cannot be prevented by MAC. Common defenses against a SYN flood attack include filtering, reducing the SYN-RECEIVED timer, and implementing SYN cache or SYN cookies. 

Answer: D 

Explanation: 

HTTP uses TCP port 80, and a TCP port 80 connection must be established for HTTP communication to occur. http://pentestlab.wordpress.com/2012/03/05/common-tcpip-ports/ 

Answer: C 

Explanation: 

248 mask uses 5 bits (1111 1000) 

42 IP in binary is (0010 1010) 

The base subnet therefore is the lowest binary value that can be written without changing 

the output of an AND operation of the subnet mask and IP... 

1111 1000 AND 

0010 1010 equals 

0010 1000 - which is .40 

/24 is standard class C mask. 

Adding the 5 bits from the .248 mask gives /29