Cisco (200-301) Exam Questions And Answers page 80

RIPv1 and RIPv2 do NOT both send the subnet mask in routing updates. RIPv1 is classful, while RIPv2 is classless. This means the RIPv1 does not send subnet mask information in routing updates, while RIPv2 does.
Both versions have the same administrative distance of 120.
Both versions have the same metric, which is hop count.
Both versions have the same maximum hop count, which is 15.
Objective:
Routing Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot RIPv2 for IPv4 (excluding authentication, filtering, manual summarization, redistribution)
Home > Knowledgebase > Cisco Certified Network Associate (CCNA) > Difference between RIPv1 and RIPv2
Cisco Press > Articles > Cisco Certification > CCDA > CCDA Self-Study: RIP, IGRP, and EIGRP Characteristics and Design

The output shows that the router IDs for RTR78 and RTR79 are the same value, which should not be the case. One of the two routers has been misconfigured with the other router's ID. This will prevent an OSPF neighbor adjacency from forming.
Other issues can that can prevent an adjacency are:
• Mismatched OSPF area number
• Mismatched OSPF area type
• Mismatched subnet and subnet mask
• Mismatched OSPF HELLO and dead timer values
The process IDs do not have to match. It does not matter whether they match or do not match because the process ID is only locally significant on the device.
The administrative distance is not misconfigured in the output. Both routers are using the default OSPF administrative distance of 110.
If the reference bandwidths do not match, it will affect the calculation of the path cost, but it will not prevent an adjacency from forming.
Objective:
Routing Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot single area and multi-area OSPFv2 for IPv4 (excluding authentication, filtering, manual summarization, redistribution, stub, virtual-link, and LSAs)
Support > Technology Support > IP > IP Routing > Troubleshoot and Alerts > Troubleshooting TechNotes > OSPF Neighbor Problems Explained

The banner logon message should not contain verbiage that includes the word Welcome. This could potentially supply grounds by a hacker that he was "invited" to access the device.
Also, although a strong password has been configured on the VTY lines, the presence of the no login command instructs the router to NOT prompt for a password.
The login command should be executed under the VTY configuration so that the router will prompt for the password.
The privileged mode password is encrypted because it is listed as an enable secret password.
The password configured on the VTY lines, Cisc0$ell$, is strong in that it contains numbers, letters, and non-numeric characters and it is at least 8 characters in length.
Objective:
Infrastructure Security
Sub-Objective:
Configure, verify, and troubleshoot basic device hardening
Cisco IOS Configuration Fundamentals Command Reference, Release 12.2 > Part 1: Cisco IOS User Interfaces Commands > Connection, Menu, and System Banner Commands > banner login

Below are the 3 cloud supporting services cloud providers provide to customer:
• SaaS (Software as a Service): SaaS uses the web to deliver applications that are managed by a third-party vendor and whose interface is accessed on the clients side. Most SaaS applications can be run directly from a web browser without any downloads or installations required, although some require plugins.
• PaaS (Platform as a Service): are used for applications, and other development, while providing cloud components to software. What developers gain with PaaS is a framework they can build upon to develop or customize applications. PaaS makes the development, testing, and deployment of applications quick, simple, and cost-effective. With this technology, enterprise operations, or a third-party provider, can manage OSes, virtualization, servers, storage, networking, and the PaaS software itself. Developers, however, manage the applications.
• IaaS (Infrastructure as a Service): self-service models for accessing, monitoring, and managing remote datacenter infrastructures, such as compute (virtualized or bare metal), storage, networking, and networking services (e.g. firewalls). Instead of having to purchase hardware outright, users can purchase IaaS based on consumption, similar to electricity or other utility billing.
In general, IaaS provides hardware so that an organization can install their own operating system.

The show arp command is used to view the Address Resolution Protocol (ARP) cache. ARP is used by the Internet Protocol (IP) to find the Media Access Control (MAC) address or the hardware address of a host. The main function of ARP is to translate IP addresses to MAC addresses. The process of obtaining the address of a computer in the network is known as address resolution. This process is accomplished by sending an ARP packet from a source to a destination host. The destination host responds to the ARP packet by replying back to the source and including its own MAC address. Once the source host receives the reply, it will update its ARP cache with the new MAC address.
The complete syntax of the show arp command is:

show arp [ip-address [locationnode-id] | hardware-address [locationnode-id] | traffic [locationnode-id | interface-instance] | trace [error [locationnode-id] | dev [locationnode-id] | events [locationnode-id] table [locationnode-id] packets [locationnode-id] | [locationnode-id]] | type instance| [locationnode-id]

The following is a brief description of the parameters used with this command:
ip-address: An optional parameter that displays specific ARP entries.
locationnode-id: An optional parameter that displays the ARP entry for a specific location. The method for entering the node-id argument is rack/slot/module notation.
hardware-address: An optional parameter that displays ARP entries that match the 48-bit MAC address.
traffic: An optional parameter that displays ARP traffic statistics.
interface instance: Either a physical interface instance or a virtual interface instance:
Physical interface instance: the naming notation is rack/slot/module/port and a slash mark between values is required as part of the notation where:
rack refers to the chassis number of the rack.
slot refers to the physical slot number of the line card.
module refers to the module number. A physical layer interface module (PLIM) is always 0.
port refers to the physical port number of the interface.
Virtual interface instance: the number range is variable depending on the type of interface.
trace: An optional parameter that displays the ARP entries in the buffer.
error: An optional parameter that displays the ARP error logs.
dev: An optional parameter that displays the ARP internal logs.
events: An optional parameter that displays the ARP events logs.
table: An optional parameter that displays the ARP cache logs.
packets: An optional parameter that displays the ARP packet receive and reply logs.
type instance: An optional parameter that specifies the interface for which you want to view the ARP cache.
An example of the output of the show arp command is shown below along with a diagram of the network in which the router resides.
R1#show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 192.0.5.1 120 0000.a710.4baf ARPA FastEthernet 0/1
Internet 192.0.5.6 105 0000.a710.859b ARPA FastEthernet 0/1
Internet 58.59.6.3 42 0000.a710.68cd ARPA FastEthernet 0/0
Internet 58.59.6.4 59 0000.0c01.7bbd ARPA FastEthernet 0/0


From the information above, we can make the following conclusions about the actions R1 will take when it receives data from PC1 destined for the Web server:
• The data frames will be forwarded out the Fa0/0 interface of R1
• R1 will place the MAC address of the Web Server (0000.0c01.7bbd) in the destination MAC address of the frames
• R1 will put the MAC address if the forwarding Fa0/0 interface (0000.a710.68cd) in the place of the source MAC address
The option stating that the show arp command is used to view the ARP statistics only for a particular interface is incorrect because this command is used to view the ARP cache. You can also view the information for a particular interface with the help of the interface instance parameter.
The options stating that the show arp command is used to view the details of neighboring devices discovered by the ARP or to view global ARP information, such as hold time and timer, are both incorrect because these are both Cisco Discovery protocol (CDP) functions, not ARP functions. The show cdp neighbors detail command is used to display details regarding the neighboring devices that are discovered by CDP, and the show cdp command displays global CDP information, such as timer and hold-time.
Objective:
Network Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot IPv4 addressing and subnetting
References:

The system LED indicates the overall health of the switch. The LED should turn solid green after a successful Power On Self Test (POST). An amber system LED indicates that there is a system-wide failure in the switch.
High utilization will not cause the system LED to turn amber.
An amber system LED indicates a general switch malfunction. It does not indicate that the switch is performing normally.
Port security violations will not cause the system LED to be amber. The system LED is used to identify the overall health of the switch.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Troubleshoot interface and cable issues (collisions, errors, duplex, speed)
Cisco > Catalyst 2960 Switch Hardware Installation Guide > LEDs

Already a statement is there in last to allow SSH Traffic for network 10.20.1.0 0.0.0.127, but Second
statement says deny ip any 10.20.1.0 0.0.0.255, so how it will work once it is denied. So the right answer is remove the --- no access-list 2699 deny ip any 10.20.1.0 0.0.0.255.

Cisco routers use access control lists (ACLs) and blackholing features to help mitigate distributed denial-of-service (DDoS) attacks. A DoS attack is an attack in which legitimate users are denied access to networks, systems, or resources. One of the most common DoS attacks is the DDoS attack, which is executed by using multiple hosts to flood the network or send requests to a resource. The difference between DoS and DDoS is that in a DoS attack, an attacker uses a single host to send multiple requests, whereas in DDoS attacks, multiple hosts are used to perform the same task.
Cisco routers offer the following features to mitigate DDoS attacks:
• ACLs: Filter unwanted traffic, such as traffic that spoofs company addresses or is aimed at Windows control ports. However, an ACL is not effective when network address translation (NAT) is implemented in the network.
• Rate limiting: Minimizes and controls the rate of bandwidth used by incoming traffic.
• Traffic-flow reporting: Creates a baseline for the network that is compared with the network traffic flow, helping you detect any intrusive network or host activity.
• Apart from these features offered by Cisco routers, the following methods can also be used to mitigate DDoS attacks:
• Using a firewall, you can block or permit traffic entering a network.
• The systems vulnerable to attacks can be shifted to another location or a more secure LAN.
• Intrusion Detection Systems (IDS), such as Network Intrusion Detection Systems (NIDS) and Host Intrusion Detection Systems (HIDS), can be implemented to detect intrusive network or host activity such as a DoS attack, and raise alerts when any such activity is detected.
Anti-DDoS guard and scatter tracing are incorrect because these features are not offered by Cisco routers to mitigate DDoS attacks.
Flow control is incorrect because flow control is used to prevent the loss of traffic between two devices.
Objective:
Infrastructure Security
Sub-Objective:
Configure, verify, and troubleshoot basic device hardening
Cisco > Support > Technology Support > Security and VPN > Authentication Protocols > Technology Information > Technology White Paper > Strategies to Protect Against Distributed Denial of Service (DDoS) Attacks > Document ID: 13634

The network 192.168.1.0 command instructs the router to activate EIGRP on every interface that belongs to the class C network 192.168.1.0. The exhibit indicates that the router is running EIGRP on two subnets of 192.168.1.0 (192.168.1.80/28 and 192.168.1.128/28). Since both of these are subnets of the same class C network number, only the class C address needs to be referenced with a network statement.
All interfaces that will participate in EIGRP must be specified with a network command that specifying the network of which the interface is a member. Failure to do so will result in neighbor relationships not forming. In the example below, Router A and Router B are directly connected, but not forming a neighbor relationship. The network they share is the 192.168.5.0/24 network. The output of the show run command for both routers reveals that Router B does not have EIGRP running on the 192.168.5.0 network.

The network 192.168.1.0 0.0.0.15 command is incorrect because only the class C network number (192.168.1.0) needs to be referenced to enable EIGRP on all subnets. It is actually valid to include an inverse mask with EIGRP network statements, but it is unnecessary in this case, and the network/mask provided does not match either of the routed networks.
The network 192.168.1.0 255.255.255.0 command is incorrect because the mask is unnecessary in this case, and if masks are included, they must be expressed inversely (0.0.0.255).
It is unnecessary to configure two network commands in this example, as both networks are subnets of the same class C network (192.168.1.0), and a single network command can enable EIGRP on both. Additionally, if specific subnets are referenced in network commands, it is necessary to include an inverse mask after them, or EIGRP will automatically summarize the command to the classful boundary.
Objective:
Routing Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot EIGRP for IPv4 (excluding authentication, filtering, manual summarization, redistribution, stub)
Cisco > Cisco IOS IP Routing Protocols Configuration Guide, Release 12.4T > Part 3: EIGRP > Configuring EIGR