Small & Large Networks
What type of devices would you want in you network to support growth?
Devices that have a fixed type/number of interfaces would not support growth. You need devices that are modular or support modularity.
What type of priority does video and voice require on a network and why?
Voice and video traffic have delay sensitive characteristics and must be given high priority over other traffic types such as web, email, and file transfer traffic.
What should you do to prevent attacks on passwords?
One of the most common types of access attack uses a packet sniffer to yield user accounts and passwords that are transmitted as clear text.
Repeated attempts to log in to a server to gain unauthorized access constitute another type of access attack.
Limiting the number of attempts to log in to the server and using encrypted passwords will help prevent successful logins through these types of access attack.
What is the command to block multiple failed login attempts on a router?
The login block-for X attempts X within X
command will cause the device to block authentication after X unsuccessful attempts within X seconds for a duration of X seconds.
What do the following show commands show you?
show running-config
show interfaces
show arp
show ip route
show protocols
show version
What type of network feature do you need to keep from having down time and loss of profit for a large business?
Redundancy is not normally found in very small companies, but larger small companies might use port density redundancy or have redundant Internet providers/links to keep form having down time.
What is VoIP?
VoIP is a technology that converts analog voice signals into digital IP packets that can be sent over an IP network.
The four classes of threats are?
The four classes of threats are as follows:
How to you securely connect to a router remotely?
Use SSH.
What is CDP?
CDP is a Cisco-proprietary protocol that can be disabled globally by using the no cdp run global configuration command, or disabled on a specific interface, by using the no cdp enable interface configuration command. Because CDP operates at the data link layer, two or more Cisco network devices, such as routers can learn about each other even if Layer 3 connectivity does not exist. The show cdp neighbors detail command reveals the IP address of a neighboring device regardless of whether you can ping the neighbor.
What information do you need to use plan for network growth?
Several elements that are needed to scale a network include documentation of the physical and logical topology, a list of devices that are used on the network, and an analysis of the traffic on the network.
What does the tracert command do?
What does tracert -6 command do?
IT shows you all devices between you and the device you are trying to connect to.
The -6 option in the command C:\> tracert -6 is used to force the trace to use IPv6.
What is Stateful Packet Inspection?
What is Packet Filtering?
What is Application Filtering?
What is URL Filtering?
Stateful packet inspection on a firewall checks that incoming packets are actually legitimate responses to requests originating from hosts inside the network.
Packet filtering can be used to permit or deny access to resources based on IP or MAC address.
Application filtering can permit or deny access based on port number.
URL filtering is used to permit or deny access based on URL or on keywords.
What are the steps to set up SSH on a router?
There are four steps to configure SSH on a Cisco router. First, set the host name and domain name. Second, generate a set of RSA keys to be used for encrypting and decrypting the traffic. Third, create the user IDs and passwords of the users who will be connecting. Lastly, enable SSH on the vty lines on the router.
What does the show ip interface brief command show you?
The show ip interface brief command is used to verify the status and IP address configuration of the physical and switch virtual interfaces (SVI).
What do you need to look at to traffic flow patterns?
Traffic flow patterns should be gathered during peak utilization times to get a good representation of the different traffic types. The capture should also be performed on different network segments because some traffic will be local to a particular segment.
What is a intermediate device?
A device passing network traffic and connecting different networks.
What is a DoS attack?
What is a access attack?
What is a reconnaissance attack?
Reconnaissance attacks - the discovery and mapping of systems, services, or vulnerabilities
Access attacks - the unauthorized manipulation of data, system access, or user privileges
Denial of service - the disabling or corruption of networks, systems, or services
What is vulnerability
A weakness or flaw that can allow an attacker to gain access to a system
What does arp -a and arp -d do in command prompt?
arp -a
Displays current ARP entries.
arp -d clears the ARP table entries.
How do you establish a network baseline?
An effective network baseline can be established by monitoring the traffic at regular intervals. This allows the administrator to take note when any deviance from the established norm occurs in the network.
What is device capacity?
The port density, processing, and memory capacity of a device.
What are the 3 AAA's?
Authentication, authorization, and accounting are network services collectively known as AAA.
Authentication requires users to prove who they are.
Authorization determines which resources the user can access.
Accounting keeps track of the actions of the user.
What is stateful packet inspection?
The ability of a device to track TCP connections and only allow returning data to the inside connection
What does the Terminal Monitor command do?
The terminal monitor command is very important to use when log messages appear. Log messages appear by default when a user is directly consoled into a Cisco device, but require the terminal monitor command to be entered when a user is accessing a network device remotely.