CCNA All in One

The Routing Information Protocol (RIP) was the first commonly used IGP in the history of TCP/IP. Organizations used RIP inside their networks commonly in the 1980s, and into the 1990s. RIPv2, created in the mid-1990s, improved RIPv2, giving engineers an option for easy migration and co-existence to move from RIPv1 to the better RIPv2. Features of Both RIPv1 and RIPv2 Like all IGPs, both RIPv1 and RIPv2 perform the same core features. That is, when using either RIPv1 or RIPv2, a router advertises information to help other routers learn routes; a router learns routes by listening to messages from other routers; a router chooses the best route to each subnet by looking at the metric of the competing routes; and the routing protocol converges to use new routes when something changes about the network. RIPv1 and RIPv2 use the same logic to achieve most of those core functions. The similarities include the following: Both send regular full periodic routing updates on a 30-...

Network security  is a completely changing area; new devices like IDS (Intrusion Detection systems), IPS (Intrusion Prevention systems), and Honeypots are modifying the way people think about security. Companies are spending thousands of dollars on new security devices, but forgetting the basic, the first line of defense: the border router. Although a lot of people may think that routers don’t need to be protected, they are completely wrong. A lot of secure problems appear all time against this kind of device and most of them are vulnerable. There are 8 steps, easy to follow, to minimize your Cisco router exposure by turning off some unused services, applying some access control and applying some security options available on that. 1- Control Access to your router The first thing to do is apply some rules to restrict all external access to some ports of the router. You can block all ports, but it is not always necessary. These commands bellow will protec...

A large number of common threats need to be considered when securing a network, but a frequently overlooked area is the security of the LAN. When people think about security, often they’re thinking specifically of the layers above Layer 2, but there’s no reason to limit a security plan to these upper layers.  A good security plan should account for  all  layers, from Layer 1 through Layer 7.   Here we are discussing about some of the most common Layer 2 attacks and how they operate. 1. Spanning Tree Protocol (STP) Attacks The Spanning Tree Protocol (STP) is used on LAN-switched networks. Its primary function is removing potential loops within the network. Without STP, Layer 2 LANs simply would stop functioning, because the loops created within the network would flood the switches with traffic. The optimized operation and configuration of STP ensures that the LAN remains stable and that traffic takes the most optimized path through the network....

1. hostname Syntax:   hostname   hostname One of the most basic network commands,  hostname  configures the hostname used for a device. This hostname identifies the device to other locally connected devices for protocols such as the Cisco Discovery Protocol (CDP), which helps in the identification of devices attached directly to the network. Although it is not case-sensitive, the hostname must follow certain rules: It must begin with a letter and end in a letter or digit, and interior characters must be letters, digits, or hyphens (-). 2. ip default-gateway Syntax:   ip default-gateway  gateway The  ip default-gateway  command configures the default gateway for a switch when IP routing is  not  enabled (with the  ip routing  global configuration command), which is typical when lower-level Layer 2 switches are being configured. The easiest way to determine whether IP routing has been enabled is to r...

QUESTION 21 Refer to the exhibit. The two connected ports on the switch are not turning orange or green. What would be the most effective steps to troubleshoot this physical layer problem? (Choose three.) A. Ensure that the Ethernet encapsulations match on the interconnected router and switch ports. B. Ensure that cables A and B are straight-through cables. C. Ensure cable A is plugged into a trunk port. D. Ensure the switch has power. E. Reboot all of the devices. F. Reseat all cables. Correct Answer: BDF QUESTION 22  A network administrator is troubleshooting the OSPF configuration of routers R1 and R2. The routers cannot establish an adjacency relationship on their common Ethernet link The graphic shows the output of the show ip ospf interface e0 command for routers R1 and R2. Based on the information in the graphic, what is the cause of this problem? A. The OSPF area is not configured properly. B. The priority on R1...

QUESTION 11  If a router has four interfaces and each interface is connected to four switches, how many broadcast domains are present on the router? A. 1 B. 2 C. 4 D. 8 Correct Answer: C  QUESTION 12  The left describes the types of cables, while the right describes the purposes of the cables. Drag the items on the left to the proper locations. (Not all items can be used.) (THE COMMUNITY SHARED THAT THERE IS ANOTHER OPTION SO STUDY ALL OF WHAT THIS CABLES ARE FOR)   Correct Answer: QUESTION 13 Match the items on the left with appropriate OSI layer on the right. (Not all options are used.) CORRECT ANSWER QUESTION 14 Which command enables IPv6 forwarding on a Cisco router? A. ipv6 local B. ipv6 host C. ipv6 unicast-routing D. ipv6 neighbour Correct Answer: C  QUESTION 15 Refer to the exhibit. What is the most appropriate sum...