CCNA3 ch 1
Terms in this set (65)
A large business environment with many users, locations, and systems is referred to as an
All enterprise networks must:
Support critical applications
Support converged network traffic
Support diverse business needs
Provide centralized administrative control
Enterprise-class equipment is designed for reliability, with features such as
redundant power supplies and failover capabilities
Failover capability is?
the ability of a device to switch from a nonfunctioning module, service, or device to a functioning one with little or no break in service.
the 3 layer hierarchical design model has three layers what are they?
• Access layer
• Distribution layer
• Core layer
what does the access layer do?
provides connectivity for the users.
The distribution layer does what?
The distribution layer is used to forward traffic from one local network to another.
what is the core layer?
The core layer represents a high-speed backbone layer between dispersed networks.
which layers form the two-tier hierarchical design?
the core and distribution layers are collapsed into one layer, reducing cost and complexity
what is the Cisco Enterprise Architecture?
it divides the network into functional components while still maintaining the core, distribution, and access layers. The primary Cisco Enterprise Architecture modules include
• Enterprise Campus
• Enterprise Edge
• Service Provider Edge
what is Enterprise Campus?
The Enterprise Campus consists of the entire campus infrastructure, to include the access, distribution, and core layers. The access layer module contains Layer 2 or Layer 3 switches to provide the required port density. Implementation of VLANs and trunk links to the building distribution layer occurs here. Redundancy to the building distribution switches is important. The distribution layer module aggregates building access using Layer 3 devices. Routing, access control, and QoS are performed at this distribution layer module. The core layer module provides high-speed interconnectivity between the distribution layer modules, data center server farms, and the enterprise edge. Redundancy, fast convergence, and fault tolerance are the focus of the design in this module.
what are the submodules of enterprise campus?
Server Farm and Data Center Module
what is the server farm and data center module?
This area provides high-speed connectivity and protection for servers. It is critical to provide security, redundancy, and fault tolerance. The network management systems monitor performance by monitoring device and network availability
what is the services module?
This area provides access to all services, such as IP Telephony services, wireless controller services, and unified services.
explain enterprise edge
The Enterprise Edge consists of the Internet, VPN, and WAN modules connecting the enterprise with the service provider's network. This module extends the enterprise services to remote sites and enables the enterprise to use Internet and partner resources. It provides QoS, policy reinforcement, service levels, and security.
explain service provider edge
The Service Provider Edge provides Internet, Public Switched Telephone Network (PSTN), and WAN services.
All data that enters or exits the Enterprise Composite Network Model (ECNM) passes through an edge device. This is the point where all packets can be examined and a decision made whether the packet should be allowed on the enterprise net- work. Intrusion detection systems (IDS) and intrusion prevention systems (IPS) can also be configured at the enterprise edge to protect against malicious activity.
what is a failure domain?
A failure domain is the area of a network that is impacted when a critical device or network service experiences problems.
what is used to minimize the chance of disruption in a network?
redundant links and reliable enterprise-class equipment
In the hierarchical design model, it is easiest and usually least expensive to control the size of a failure domain in the _________ layer because network errors can be contained to a smaller area, thus affecting fewer users
what is switch block/department block/building block
when Routers, or multilayer switches, are deployed in pairs, with access layer switches evenly divided between them
Each _______ acts independently of the others. As a result, the failure of a single device does not cause the network to go down. Even the failure of an entire switch block does not affect a significant number of end users.
Included in a basic network design strategy are the following recommendations:
- Use expandable, modular equipment or clustered devices
- include modules that can be added, upgraded, and modified, as necessary, without affecting the design of the other functional areas of the network
- Create an IPv4 or IPv6 address strategy that is hierarchical
- filter trafic
Advanced network design requirements include:
- Implementing redundant links in the network between critical devices and between access layer and core layer devices.
- Implementing multiple links between equipment, with either link aggregation (EtherChannel) or equal-cost load balancing
- Implementing wireless connectivity to allow for mobility and expansion
- Using a scalable routing protocol
what is a downside to redundant paths?
logical Layer 2 loops
what can prevent logical Layer 2 loops
Spanning Tree Protocol (STP)
what is Spanning Tree Protocol (STP)
STP allows for the redundancy required for reliability but eliminates the switching loops. It does this by providing a mechanism for disabling redundant paths in a switched network until the path is necessary, such as when failures occur. STP is an open standard protocol, used in a switched environment to create a loop-free logical topology.
what is link aggreation
Link aggregation allows an administrator to increase the amount of bandwidth between devices by creating one logical link made up of several physical links. EtherChannel is a form of link aggregation used in switched networks
what are some advantages of etherchannel?
- saves money
- Most configuration tasks are done on the EtherChannel interface, instead of on each individual port - uses load balancing
OSPF Routers reach a FULL state of adjacency when?
they have synchronized views on their link-state database
when are OSPF link-state updates sent?
when network changes occur
All non-backbone areas must directly connect to _____
Campus LAN Switches:
To scale network performance in an enterprise LAN, there are core, distribution, access, and compact switches.
The Cisco Meraki cloud-managed access switches enable virtual stacking of switches. They monitor and configure thousands of switch ports over the web, without the intervention of onsite IT staff.
Data Center Switches:
A data center should be built based on switches that promote infrastructure scalability, operational continuity, and transport flexibility. The data center switch platforms include the Cisco Nexus Series switches and the Cisco Catalyst 6500 Series switches.
Service Provider Switches:
Service provider switches fall under two categories: aggregation switches and Ethernet access switches. Aggregation switches are carrier-grade Ethernet switches that aggregate traffic at the edge of a network. Service provider Ethernet access switches feature application intelligence, unified services, virtualization, integrated security, and simplified management.
Virtual Networking switches:
Networks are becoming increasingly virtualized. Cisco Nexus virtual networking switch platforms provide secure multitenant services by adding virtualization intelligence technology to the data center network.
what are some common business considerations when selecting switch equipment
- port density (no. of ports available)
- port speed
- frame buffers
what are Frame Buffers
The ability of the switch to store frames is important in a net- work where there might be congested ports to servers or other areas of the network.
what are forwarding rates?
Forwarding rates define the processing capabilities of a switch by rating how much data the switch can process per second. Entry-level switches have lower forwarding rates than enterprise-level switches
what is wire speed?
Wire speed is the data rate that each Ethernet port on the switch is capable of attaining.
Access layer switches typically do not need to operate at full wire speed, because they are physically limited by their uplinks to the distribution layer. This means that less expensive, lower-performing switches can be used at the access layer, and more expensive, higher-performing switches can be used at the distribution and core layers, where the forwarding rate has a greater impact on network performance.
what is power over ethernet?
Power over Ethernet (PoE) allows the switch to deliver power to a device over the existing Ethernet cabling. This feature can be used by IP phones and some wireless access points
what allows virtual stacking of switches?
Cisco Meraki cloud-managed access switches
where are multi layer switches typically deployed?
the core and distribution layers
what are multi layer switches?
Multilayer switches are characterized by their ability to build a routing table, support a few routing protocols, and forward IP packets at a rate close to that of Layer 2 forwarding
Multilayer switches often support specialized hardware, such as application-specific integrated circuits (ASIC). what are ASIC's?
ASICs can streamline the forwarding of IP packets independent of the CPU.
what do routers use to route packets to their destination?
the network portion of the destination ip address
what are some beneficial functions of routers?
- Provide broadcast containment
- Connect remote locations
- Group users logically by application or department
- Provide enhanced security
what is a branch router?
Branch routers optimize branch services on a single platform while delivering an optimal application experience across branch and WAN infrastructures. Maximizing service availability at the branch requires networks designed for 24x7x365 uptime. Highly available branch networks must ensure fast recovery from typical faults, while minimizing or eliminating the impact on service, and provide simple network configuration and management.
what is a network edge router?
Network edge routers enable the network edge to deliver high-performance, highly secure, and reliable services that unite campus, data center, and branch networks. Customers also want to access content anytime and anyplace they choose, over any device, whether at home, at work, or on the go. Network edge routers must deliver enhanced quality of service and nonstop video and mobile capabilities
what is a Service Provider Routers?
- end-to-end scalable solutions and subscriber-aware services. - optimise operations, reduce expenses, and improve scalability and flexibility to deliver next-generation Internet experiences across all devices and locations. These systems are designed to simplify and enhance the operation and deployment of service-delivery networks.
what is Out-of-band management?
is used for initial configuration or when a network connection is unavailable.
what does out of band management require?
- Direct connection to console or AUX port
- Terminal emulation client
what is In-band management?
In-band management is used to monitor and make configuration changes to a net- work device over a network connection. Configuration using in-band management requires:
what does In-band management require?
- At least one network interface on the device to be connected and operational
- Telnet, SSH, or HTTP to access a Cisco device
A _______ should have a connection to two different access layer switches. It should have redundant modules when possible and a power backup source. It might be appropriate to provide multiple connections to one or more ISPs.
What are the expected features of modern enterprise networks?
Support for converged network
Support for critical applications
Which methods help to prevent the disruption of network services?
Using redundant connections to provide alternate physical paths
Installing duplicate equipment to provide failover services
Which feature could be used in a network design to increase the band width by combining multiple physical links into a single logical link?
Which network design solution will best extend access layer connectivity to host devices?
Implementing wireless connectivity
How much traffic is a 48-port gigabit switch capable of generating when operating at full wire speed?
48 Gb/s, by providing full bandwidth to each port
Which type of router would an enterprise use to allow customers to access content anytime and anyplace, regardless of whether they are at home or work?
Network edge routers
What is a characteristic of out-of-band device management?
It requires a terminal emulation client.
The number of ports available on a single switch is referred to as _______
Among the beneficial functions of a router are enhanced network security and containment of ______ traffic.