CCDA
Terms
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- What is a Circuit Switched PSTN (Phone Service, Analog Modems, ISDN)
-
-dedicated circuit paths established during call
-ISDN combines voice and data and serves as a backup - Packet and Cell Switched
-
ex. X 25, Frame Relay, SMDS, ATM
-permanent virtual circuits which deliver packets of data between customer sites
ATM uses cells and provides QoS - What are the 4 emerging WAN technologies?
-
-DSL-ordinary copper lines
-LRE-ethernet over telephone using DSL
-Cable-coaxial and fiber that supports analog and digital video
-Wireless - 4 types of WAN Interconnections
-
-Enterprise edge and ISP Edge modules
-Internet
-sites across ISP Network
-Enterprise sites across SP network - How do you plan and design the Enterprise Edge WAN?
-
-Analyze customer requirements
-Characterize customer rewuirements
-Desgin topolgy - Considerations when planning and designing WAN
-
Application aspect
Technical aspect
Cost - Determing Maximum Offered Traffic
-
- end users require minimum response times
-network managers require maximum link utilizations - Typical Applications on Client Enterprise Edge APplicaitons
-
Internet Apps (mail, web, public servers)
Ecommerce apps - 4 types of network geography
-
-interbuilding- b/t 2 buildings
-intrabuilding- within buildings
-distant remote building-
-distance remote building over 100km - What is a Leased Line
- -physical wire
- Intrabuilding Structure
-
-inside building connections
-access and distribution layers
-UTP (copper) or Optical fiber - Interbuilding Structure
-
-connection between 2 buildings
-distribution and or core layers
-optical fiber (MM or SM) - Distant Remote Building Structure
-
-uses company owned fiber (SM)
-through enterprise WAN - What is switching later decicion dictated by?
-
-network service capabilities (QoS, policing, etc.)
-size of network segments - L2 offer load sharing by?
- Distributing VLANs accross different uplinks
- How do L3 perform load sharing?
- between ports
- When designing enterprise campus what do you take in consideration?
-
-application traffic
-multicast traffic
-QoS - When designing campus models concentrate on:
-
-access and distribution
-backbone
-server farm
-edge distribution - What do network traffic represent?
- -organizational application traffic flows
- Traditional Network vs. Modern Networks in network traffic
-
Trad- 80/20 rule (20% into WAN)
-servers in workgroup
-most traffic LOCAL
Modern- 20/80 (80% in WAN)
-servers in server farm - What do IP Multicast deliver?
- a traffic stream to mulitple destinations
- IGMP- Internet Group Managment Protocol
- - hosts that are interested in receiving data flowing to a particular group must join the group by using this
- CGMP- Cisco Group Management Protocol
- -cisco propriety solution implemented on all Cisco LAN switches
- IGMP Snooping
- snooper that looks into the L3
- What are the L2 QoS catergories ? (4)
-
-classification and marking
-scheduling
-congestion management
-policing and shaping - Policing
- input of device
- Shaping
- output of device
- What are the Building Access Design considerations
-
-# of users and ports
-cabling
-performance
-redundancy
-CONNECTIVITY SPEED HOSTS OR UPLINKS
-VLAN deployment - What is the building distribution design and what are the considerations?
-
-provides access aggregation to the backbone
-considerations
-performance
-#of ports of neighbhors
-redundancy
-intelligent network devices
-manageability - What is the campus backbone and what are the considerations?
-
-provides high speed connectivity to building distribution and server farm
-considerations
-L2 or L3
-high capacity ports for distribution
-redundancy - What does server farm model connect to and what are its considerations?
-
-connectivity of servers in enterprise campus network
-considerations- access control, huge traffic demands, switch and link oversubsciptions, server connectivity options - What are servers in the server farm connected via?
-
-single NIC
-dual NIC
-server load balancing switch - What layers in the OSI model does the WAN cover?
- -physical, data link, netowrk
- What are WAN technologies?
- -leased lines, circuit switching, packet switching, and cell switching
- Layers in the Heirarchical Model
- Access, Distribution, Core (Backbone) Layers
- Why is Design So Important?
- Networks are Critical and Complex
- According to the OSI Model, where are the Layers in the Heirarchical Model Placed?
-
Access- Placed in the protocols of the application, presentation, session, and transport
Distribution- core of the transport and network layer interaction
Core- Transport - Access Layer
-
-Local and Remote Workgroup Access
-Controls traffic by localizing service requests to the access media
-Examples of what is on the Access Layer- routers, Firewalls, PC's, L2 Switches, WAN, Internet, PSTN - Distribution Layer
-
-Provides policy based connectivity
-QoS, Access Lists, Security
-PACKET MANIPULATION
-makes efficient use of bandwidth
-Prioritize traffic
-Ex. Routers, L2/3 Switches - Core Layer
-
-High Speed Switching
-Send data to network as fast as possible
-Maintain connectivity when circuits connecting them fail
-Ex. Servers, L2 or L3 Switches - Roles of the Access Layer
-
-Clients Access Network through this layer by using LANs and WANs (shared vs. switched), PSTN (shared vs. switched vs. leased line)
-Access may only be granted by those authenticated - Access Layer Design Options
-
L2- determines single broadcast domain
L3- optimized to satisfy the needs of a particular user, static routing, Dial-on-demand (cuts WAN costs) - Layer 2 VLANs Example
-
-for traffic management
-workstations connected to VLANs with L2 switches
-switches are connected via VLAN Trunk
-Switch sends appropriate VLAN to trunk - Roles of Distribution Layer
-
-Separation between access and core
-aggregates all users
-L2 or L2/3 Switching
-do ALL OF PACKET MANIPULATION
-determines department or workgroup access
-provides redudandant connections - What are the benefits of swtiched vs. shared technology?
-
-high bandwidth support
-larger network diameter
-addition L2 L3 devices
-high availability - Distribution Layer Design Options
-
-L3 between access and core
-route aggregation, redistribution, and filtering
-redudundancy, load balancing
-Policy based decisions
-filtering by source and destination address
-filtering by input/output ports
-static routing
-security, QoS
-hiding internal network #'s by route filtering - Distribution Layer in Routed Campus Network (2-16)
-
-high redundant connectivity- towards access and core
-L3- access and distribution and extended towards core
-2-way redistribution to exchange routes between routing processes
-route filtering configured towards access layer
-route summarization configured toward core layer - List 3 key distribution layer features
-
1.distribution layer aggregates access layer links
2.represents a routing boundary between access and core
3.provides policy based connectivity - Role of Core Layer
-
-provide fast and efficient data transport
-high speed backbone, redundancy and fault tolerance
-design options- L2 or L3 - What are 3 roles of core layer in LAN design
-
-high speed data transport
-fast convergent infrastructure with high level of redundancy
-avoids data manipulation - Drawbacks of Enterprise Networks (3)
-
1.diffuclt to manage
2.difficult to scale
3.difficult to evaluate end to end - Enterprise Composite Network Model Goals (3)
-
1.more deterministic networks
2.small modules ease design and improve scalabilty
3.easier to add modules - Benefits of Enterprise Composite Network Model
-
-concentrate on each module and on relationships between modules
-additional integrity in network design
-ease in evaluating network solution (IP Telephony, etc.) and any intelligent network service (security, QoS) - 3 Functional Areas of ECNM (2-31)
-
1.Enterprise Campus- all network elements for independent operation within one campus location
-no remote connections or internet access
2.Enterprise Edge- aggregates connectivity from various elements at edge of enterprise campus network-
-routes traffic from edge to enterprise campus
-includes remote locations, business partners, mobile users, and Internet
3.Service Provider Edge-enable communication with other networks using different WAN technologies and Internet Service Providers (ISPs) - ECNM Functional Detail (2-33)
- Network Management connects to Enterprise Campus which connects to Enterprise Edge which connects to Service Provider Edge
- Name 3 modules part of the Enterprise Campus.
-
1.Network Management Module
2.Edge Distribution Module
3.Server Farm Module - Enterprise Campus Functional Area- name all components- be able to draw this out- (2-36)
-
Network Management-
Campus Infrastructure
Server Farm
Edge Distribution - Campus Infrastructure Module (2-38)
-
-connects users with Server Farm and Edge Distribution Modules
-components:
-Building Block- Building Access, Building Distribution
-Campus Backbone
-Server Farm- Internal Email, Corporate Server, CallManager
-Edge Distribution - Campus Infrastructure- Building Block (2-39)
-
-Contains Building Access- end user workstations, printers, IP phones, etc
-Building Distribution- uses L3 switches- provides aggregation of access networks- performs routing, QoS, access control - Campus Infrastructure- Campus Backbone (2-40)
-
-high speed switching
-redudandcy
-L3 - Network Management Module (2-41)
-
-performs intrusion detection, system logging, and Terminal Access Control Sytem Plus (TACACS+), OTP
-Examples- OTP, Access Control Server, IDS detector, Syslog, System Admin, Out of Band Management
-Cisco IOS routers act as terminal servers - Server Farm Module (2-42)
-
-contains internal email and corporate servers
-switches are cross connected to 2 different switches for redundancy and load sharing
-include Internal Email, Corporate Server, Call Manager - Edge Distribution Module (2-43)
-
-routes traffic into Campus Backbone Submodule
-uses access control to filter traffic
-L3 switching - Network Solution in the Enterprise Campus (2-44)- example of how IP telephones are used to call each other
- check out description-
- What module connects Server Farm to Edge Distribution Module?
- Campus Backbone Submodule
- Enterprise Edge Functional Area- 4 modules
-
-going out from enterprise into the world
1.E-Commerce
2.Internet Connectivity M
3.Remote Access and VPN
4.WAN module - E-Commerce Module (2-48)- to build a successful interface for e-commerce navigation
-
-web servers
-application servers
-database servers
-firewall or firewall routers
-network intrustion detection system (NIDS)
-L3 switch with IDS modules - Internet Connectivity Module (2-49)
-
ex. corporate website without people connecting intranet-
-SMTP mail servers
-DNS Servers
-FTP/HTTP
-Firewall routers
-L2 switches
-Edge Routers - Remote Access and VPN Module
-
-dial in access concentrators
-VPN concentrators
-Firewalls
-L2 switches
-NIDS appliances - WAN module
-
-connects to Frame Relay/ATM
-uses different WAN technologies for routing traffic between remote sites and central site - What are servers on the Internet Connectivity Module?
- public servers
- What 3 servers to E-commerce modules use for web communication with users who are running apps and storing data?
-
1.database
2.apps
3.web - Service Provider Edge Functional Area
-
-implemented by enterprise itself
-contain ISP and PSTN and Frame Relay/ATM (L2 and encapsulation) - Name 2 modules that connect to Remote Access and VPN module
- PSTN and Internet Connectivity Module
- Name the types of security for Enterprise Campus and Enterprise Edge.
-
EC- internal security
EE- from external threats - Internal Security- where is packet manipulation? in campus infrastructure
- Building Distribution
- Is there packet manipulation in campus backbone?
- No
- go over slide 2-70
- do we need to memorize this?
- External Threats types (2-73)
- IP spoofing, password attacks, DoS, application layer attacks
- Where is the first front protection against external threats?
- Enterprise Edge
- Which module of ECNM is responsible for AAA and stores OTP?
- Network Management Module
- Importance of High Availabilty
-
-no down time
-route redundancy, link redundancy
-redundant connections to critical workstations and servers - How to design high availability.
-
-anaylze business and tech goals
-identify critcal apps
-document tradeoffs between costs and redudancy
-duplicate vital links and connect them to different devices - High Availabilty in Server Farms- what type? (2-78)
-
-dual attachement- increase availabilty and prevent session loss-
-attachemnt through redundant transceiver
-redundant NIC
-Fast EtherChannel and Gigabit EtherChannel port bundles - Physical Redundancy- Redundant Transceiver Attachment (2-79)
-
-activates back up link if primary fails
-cannot detect failures beyone physical link- it can;t tell if server is down
-implemented on servers - Physical Redundancy- Redundant NIC Attachment (2-80)
-
-2 NIC cards as single logical interface
-uses one MAC address for both interfaces
-backup activated when primary gone - Designing Route Redundancy Purposes (2)
-
1. minimize link failures
2. minimize interneteworking device failure - Designing Route Redundancy- how to make connection redundant:
-
- parallel physical links between switches and routers
-backup LAN and WAN links - How to make network redundant
-
-full mesh
-partial mesh - How can enterprise edge create redundancy?
- using an ISDN backup interface
- What protects a primary leased line?
- ISDN
-
What is ideal for a campus backbone?
What is ideal for a distributed network? -
CB- full mesh
DN- partial mesh - What is a network solution?
-
-network based application that runs over the network infrastructure
ex. IP Telephony, IP VC, conent and Storage networking - Difference between IP Telephony and IP VC?
-
IP T- phone and call manager, originates from phone, voice in- IP out
IP VC- phones take analog voice and convert into packets by voice-enabled routers - 4 main IP Telephony Components
-
1.IP phones
2.Swtiches with inline power
3.Cisco CallManager
4.Voice gateway - In ECNM how does the Voice Network Design correlate to all the components?
-
-Building Access- connectivity, packet classification, power to IP phones
-Building Distribution- wiring closets, packet reclassification
-Campus Backbone- fast packet switching between modules
-Server Farm- enables connection to Call Manager
-Enterprise Edge- extend IP Telephony to PSTN, IP WAN, and Internet -
3 Content Delivery Functions
and where are they present in the network modules? -
1.Caching- presnt in any network module
2.Content Routing- present in any network module
3.Content Swtiching- Campus backbone, server farm, internet connectivity, and E-commerce - Describe the route of Content Caching
-
1.Client request to origin
2.router intercepts traffic and forwards to cache
3.cahce miss
4.content request to origin
5.origin returns content
6.content stored in cache
7.content sent to client - Route of Content Routing
- 2-102
- What 3 components do design documents usually contain?
-
1.desgin
2.design requirements
3.implementation plan - Detailed Structure of a Design Document (1-151)
-
1.intro
2.design requirements
3.exisiting network infrastructure
4.design
5.proof of concept (pilot or prototype)
6.implementation plan
7.appendices - Pilot vs. Prototype Network
-
Pilot- tests and verifies design before network is launched
Prototype- tests and verifies design in an isolated network (to an exisiting network) - Planning a Design Implementation
-
-implement each step separately
-incremental implementation - Which 2 tools should be used during network design process?
-
-network modeling tools
-simulate and test tools - Network Design Tools (4)
-
1.Network modeling tools- takes parameters and puts it into a software
2.Strategic Analysis Tools- what if tools
3.Simulation and Verification- run tests
4.Deciscion Tables- manual tables, helps in network designs - After examining exisiting network what kind of document do you create?
- Draft Design Document
- Describe the different sections in Draft Design Document.
-
1. Design Requirements
2.Existing Network Infra
2.1 Network Topolgy (physical and logical- L1 and L3)
2.2 Network Audit
2.3 Apps used in network
2.4 Network health
2.5 Recommendations of changes - How should you characterize the exisiting network? (3)
-
1. customer input
2. network audit
3. network analysis - What 3 sources can be used to produce a detailed description of design requirements?
-
1.RFP/RFI
2.Direct customer input
3.existing documentation describing the network - How do you create the design requirements document?
-
-extract customer requirements (RFP, RFI)
-query customer for raw requirements
-produce draft document
-verify desgin requirements
-revise if necessary - What are customer requirements extracted from? (3)
-
RFP- request for proposal
RFI- request for information
Direct Customer Input - List the 8 steps in the Design Methodolgy Process Review.
-
1.Identify customer requirements
2.Characterize exisiting network
3.Design topolgy and network solutions
4.PLan implementation
5.Build pilot (optional)
6.Document the design
7.Implement and very design
8.Monitor and revise if necessary - What is the physical address that every node is connected to called?
- MAC address
- What must all computers connected to the Internet must have in order to communicate with other Internet nodes/hosts?
- IP address or logical address
- What is the connectionless protocol that operates at the transport layer?
- User Datagram Protocol (UDP)
- What is the format required for delivery to the Network Layer?
- Segments
- Ethernet half-duplex communications
- two way transmissions but only one direction at a time- nodes must agree to only talk one at a time
- OSI Model
- ASPTNDP
- OSI Summary- Applications Layer- name the protocols and devices/services
-
-FTP, HTTP, Telnet, DNS
-devcice/services- Web browser - Examples of Presentation Layer
- MPEG, JPEG, MIDI, TIFF
- Examples of Session Layer
- RPC, NFS, SQL, X-Windows
- Examples of Transport Layer
- -TCP, UDP
- Examples of Network Layer and devices at this layer
-
ex- IP, ICMP, ARP, RARP
devices- router - Examples of Data Link and devices
-
ex- Ethernet, Frame Relay, HDLC
devices- bridge, switch, NIC - Examples of Physical and devices
-
ex- T1, leased line, 56Kbps services
devices- cabling, repeater - Data formatting handled by which layer?
- Presentation layer
- 3 phases of establishing communication are:
- -negotiate duplex, transfer data, connection release
- Which layer that ensures that the proper formats are used for a variety of mulitmedia formats?
- presentation layer
- DNS is what type of protocol?
- Application
- What are the TCP/IP primary transport layer protocols?
- TCP, UDP
-
Port #'s for the following:
DNS
FTP
HTTP
SMTP
SNMP
TELNET
TFTP -
53
20
80
25
161
23
69 - IP address class characteristics
-
A- 1.0.0.0-126.0.0.0- network.node.node.node
B- 128.0.0.0-191.255.0.0- network.network.node.node
C- 192.0.0.0-223.255.255.255- network.network.network.node -
Switched vs. Shared numbers
bandwidth
range
intelligent devices (Y o N)
High Avalalability (Y o N) -
bandwidth
-sw- > 10 Mbps sh- < 100 Mbps
range
-sw- 1km<< sh- < 500m
switched have intelligent devices and high availabilty - Why is LAN switching technology better than shared LAN technology?
- - LAN switching allows more than one port to communicate simultaneously
- What is application characterization?
-
-provides information on the network usage and response times
-influences the tranmission medium selection - Name 4 types of applications
-
peer to peer
client distributed servers
client server farm
client enterprise edge servers - typical applications on peer to peer
-
ip telephony
file sharing
videoconferencing systems - client distributed server applications examples
-
servers located close to clients
-servers in clients in same VLAN
-each VLAN has own server - CLient Server Farm Applications Example
- -mail servers, file servers, database servers
- What are the 5 campus design decisions?
-
-geography
-applications
-transmission media
-swtiched or shared (switches or hubs)
-L2 or L3 switching - What does physical media in the network design determine?
-
-connection speeds
-device to device distance - What are the 2 types of physical connection used?
-
-copper
-optical fiber -
Copper vs. Fiber-
bandwidth
range
deployment area -
Bandwidth
c- ethernet: <1 Gpbs LRE- 15 Mbps
F- <10 Gbps
range
c-ehternet <100m LRE- < 1.5 km
f- MM<550m SM <100km
area
c-wiring closet
f- internode/interbuilding -
Summary Report- what is it used for?
(do this after the characterization of the network) -
-describe software features required by customer
-describe possible problems (network health)
-IDENTIFY ACTIONS NEEDED TO PREPARE THE NETWORK FOR IMPLEMENTATION
-influence on customer requirements - Cisco Manual Analysis Tools (2)
-
NBAR
NetFlow - Cisco Software or hardware based network analyzers (2)
-
-Cisco FlowCollector
-Cisco Data Analyzer - 3rd party network analyzers (4)
-
-Sniffer
-Network Monitor
-EtherPeek
-MRTG - Network Application Discovery
-
-describing requirements of discovered applications
-importance
-security
-QoS
-Scope (in which network modules an application is present) - What are the 3 address assignment strategies available in IPv6?
-
address assignment with DHCP
static
statless autoconfiguration - Magic Number
- A6
- Differences between IPv4 and IPv6
-
-IPv6 address longer
-6 header changed
-6 uses multicast addresses instead of broadcast addresses
-6 requires adaption of routing protocols -
3 major transition strategies
look at pages 5-76 to 5-79 for more information on each strategy -
-dual stack
-tunneling
-translation - What does the network architecture include? (4)
-
-applications
-enabling network solutions
-pre-requisite systems
-network infrastructure with intelligent systems - If don't use site or link-locad address for IPv6 what do you use?and whats its header?
-
global aggregatable address-
header- 001 - What is the investment and running costs of private WAN?
- -owner must buy, configure, and maintain the physical layer connectivity and terminal equipment required to connect the locations
- What is the investment and costs of Leased?
-
-bandwidth is leased from a carrier company with either private or leased terminal equipment
-company pays for allocated bandwidth where oir not it is used - What is the investment and running costs of shared?
-
-carriers offer a variety of switching transports for user traffic- physical resources in core are shared with many users
example: switching technologies - What does hardware selection incorporate according to WAN technologies and what are the considerations?
-
-selection of L2 functions
-considerations- port density, packet throughput, future expandabilty, redundancy - What are the Software features when building a WAN and what are the considerations?
-
-L3 performance
-considerations- forwarding decisions, optimization of bandwidth usage, security - T or F are redunandant links necessary in WANs?
- T
- Name 4 ways to optimize bandwidth usage on WAN links?
-
-data compression
-window size
-queuing
-traffic shaping and policing -
Define Data Compression
-what does it do?
-where does it take place?
-two types of implementation -
-can compress header and or data
-reduces size frame of data to be transmitted over a network link
-takes place on an entire-packet, header only, payload only basis
-implementation- software or hardware based - Name 2 products of Data Compression
-
-Link Access Procedure Balanced (LAPB) payload compression using Lempel-Ziv Stack or Stack Predictor (Payload)
-Van Jacobson Header Compression for TCP/IP -
What does window size do?
what is it important for? -
-specifies maximum number of frames that may be transmitted without recieving an acknowledgement
-the smaller the window size the more acknowledgement
-important for long and fast transmissions - What does queuing do?
- -allows network administrators to manage varying demands of applications on networks and routers
- Name the 3 basic types of queuing.
-
-weighted fair queuing
-priority queuing
-custom queuing -
Weight fair queuing-
-definition -
-bulk queuing
-FIFO basis
-assess size of each packets
-makes sure big guy doesnt push little guy - Priorty Queuing
-
-sets up 4 interface queues
-always empties first bucket first (first bucket has the highest priorty) - Custom Queuing
-
-16 buckets
-sets priorities for each bucket, but goes to next bucket once emptied
-fairer solution - What are 2 mechanisms used to rate limit traffic classes and explain each.
-
-traffic shaping- delays excess packets to stay within rate limit
-traffic policing- drops excess traffic to stay within rate limit - Where is data compression, queuing, policing, shaping found?(on SP edge)
-
data compression- ISP into e-commerce
queuing- ISP into internet connectivity
-policing- SP into WAN
-shaping - SP into WAN - What is a benefit of ISDN over analog PSTN connectivity?
- -increased bandwidth, reduced call set up time, reduced latency, and lower signal to noise ratios
- TDM vs. Packet Switching
-
-TDM- point to point connections reserved for transmissions
-Packet Switching- share SP network resources dynamically- subscriber charged on per packet basis- QoS needed - What are the on-demand connections?
-
-ISDN
-Analog Modem Access - What are the always on connections?
-
-TDM
-Packet Switching
-Frame Relay
-X 25 - IGP- Interior Gateway Protocols- for inside autonomous systems- list the different types of them
-
-RIPing
-OSPF
-Integrated IS-IS - Frame Relay vs. X.25
-
-FR- operates at L2 protocol suite, more reliable connection services and a higher degree of reliabilty and higher performance and greater transmission efficiency
-X.25 operates at L3 - Name 3 Network Topologies
-
-hub and spoke-
-full-meshed
-partial meshed - What is a solution for minimum down time?
-
-redundancy
-load sharing - Name 3 WAN backup technologies
-
-dial back up routing (ISDN)
-permanent secondary WAN link
-Shadow permanant virtual circut - IPv6 routing protocol considerations
-
-IGP
-EGP
RIPing, IS-ISv6, BGP+ - EGP- exterior gateway protocols example
- BGP+
- OSPF - open shortest path first
-
-similiar to IPv4
-carry IPv6 addresses
-link-local addresses used as source
-IPv6 transport - Integrated Intermediate System-to-Intermediate Systems (IS-IS)
-
-same as IPv4 woth some extensions
-two new types, lengths, values (TLVs)
-IPv6 reachability
-IPv6 interface address
-new protocol identifier - BGP4+ (Multiprotocol Extensions to BGP, RFC 2283), RFC 2545
-
-mulitprotocol extensions for BGP4 enable other protocols besides IPv4
-new identifier for the IPv6 address family
-IPv6 specific extensions - What are the address assignment strategies for static?
- same as IPv4
- What are the address assignment strategies for dynamic?
-
link-local
stateless
stateful using DHCPv6 - What are the two IGP IPv6 routing protocols supported by Cisco?
-
IS-ISv6
RIPing - Private and Public Translation Options (3)
-
-one to one
-many to one
-combination - What is the translation criteria in the private and public translation?
-
-access to public network
-public visibilty - Examples of three translation options
-
one private address to one public address- private to public (addresses visible from public network)when servers must be visible
many private addresses to one public addresses: systems that need to access public network but do not need ot be seen by outside world
combination- combination of both techniques - Where are public addresses used in the enterprise network?
-
-internet connectivity module
-e commerce module
-remote access and VPN module -
Classful Routing Protocol
does it send subnet? -
-does not send subnet
-address sent either way -
Classeless Routing Protocol
does it send subnet? - -sends subnet
- How do you reduce routing overhead?
- -route summarization
- What is the static IP address assignement?
- management overhead
- What are the 2 ways dynamic IP address assignment?
-
-easy renumbering
-servers assign addresses - Static Address criterias
-
-up to 30 users
-manual recofig of hosts
-easy address tracking
-IP addresses available at any time
-minor secuirty risk - dynamic address criteria
-
-more than 30 hosts
-only DHCP server reconfig is needed
-redundant DCHP required
-any device gets IP address - Where are static IP addresses located? On enterprise module...
-
-network management
-server farm
-maybe pc's
-ecommerce
-internet connectivity
-maybe remote access VPN
-WAN - Where are dynamic addresses located?
-
-users
-remote access and VPN - What are the 3 possible DHCP address allocation mechanisms?
-
-manual
-automatic
-dynamic - Describe the three possible address allocation mechanisms
-
-manual- network administrator manually assigns MAC/IP address, DHCP used
-automatic- IP address is permanently assigned to host
-dynamic- pool of IP addresses that server gives to device - Do Dynamic Host Configuration Protocols need servers?
- Yes
- Describe what happens when link disconnected using ISDN as backup?
-
-backup connection from remote site router to enterprise edge router established
-server in remote acces and VPN is preconfigured to honor an alternative path - Describe a Permanent Secondary WAN link
- this is a new link that provides a backup link that can be used if a primary link fails
- What determines link failure?
- -routing protocols
- What do load balancing do?
- -increases overall bandwidth availabilty
- Descibe Shadow PVC
-
-used only if primary PVC is unavailable
-gets two connections for the price of one - SONET/SDH
-
-bandwidth alternative
-establishes p2p circuits using TDM frames in ring topoligies- guarnateed bandwidth
-automatic recoveries - DWDM- dense wavelength division multiplexing
-
-improved signaling mechanisms to optimize bandwidth usage
-used inside SONET/SDH ring - Dark Fiber
-
-edge devices directly connected to regenerators or DWDM concentrators
-use L2 encapsulation - What 2 encapsulations are supported in SONET/SDH network?
-
-IP(POS)
-IP over ATM - What type of connection in Sonnet?
- point to point
- HDSL
-
-mature T1 technology that provides symmetric communications up to 1.54 mbps
-data travels over two pairs of wires instead of one
-does not support PSTN - PPPoA
-
-CPE acts as a ethernet-to-wan router
-PPP session established between CPE and L3 access concetrator - ask about PPPoE/ PPPoA and Chap/PAP
- ask
- LRE what does it use?
-
-existing ethernet, DSL and digital modulation techniques with ethernet
-p2p transmissions - full duplex with 15Mbps
-can connect to ISDN, PBX -
Cable Modem Termination System
also called uBR -
-high speed connectivity and deployed at company's headend
-forwards data upstream to connect to either the PSTN or Internt
-a - 3 types of Wireless Technologies
-
-broadband fixed- building to building
-mobile- cell, GSM, GPRS, UMTS
-wireless LAN- intrabuilding CMN - p2p- how do they communicate with?
-
-allocates separate sectors in channel
-advantage is speed, not sharing bandwidth - VPN definition
- -connectivity deployed on a shared infrastructure with the same policies and performance as private network with lower cost
- VPNs are grouped according to what 3?
-
-access- access to customers intranet or extranet over shared infrastructure
intranet VPNs- extends corporate network across a shared infrastructure
extranet VPN- extends connectivity to business partners, suppliers, and customers - Connectivity options for VPNs are (3)
-
-overlay
-VPDNs
-peer to peer - Overlay Option
-
-permanent circuit
-like buying a pipe, won't knows what goes in (runs along provider's backbone) - VPDN example
- use dial in infrastructure - use ISDN, DSL, or cable to connect to SP edge
- Peer to Peer VPN
-
-utilizes MPLS/VPN technology
-enables customers to use any IP address space
-no overlapping IP address space problems - Name 3 Benefits of VPNs
-
-flexibilty-extends networks to users
-network cost- dedicated bandwidth and dial up cost savings
-scalabilty-improve geographic coverage - Which VPN model is not supported by ISP infrastructure?
- -L3 overlay model
- 3 methods for connecting noncontiguous private network over a public IP network
-
-IP routing without contraints
-GRE tunnels
-IPSec tunnels - GRE tunnels
-
-user initiated
-doesn't encrypt or gurantee integrity
-standard L3 encapsulation - IPSec Tunnels
-
-user initiated
-flexible and secure - IPSec compared to GRE (4-90)
- -IPSec are secure and can be combined with GRE, have encryption
- IP address stucture
- -network, host
- What part of the IP address does the router care about?
- Network
- Class A
-
-0-127
always starts 0
first octet
255.0.0.0/8
has 16,777,214 hosts available - Is 127 used?
- No it is used for loop testing
- Class B
-
128-191
starts with 10
255.255.0.0/16
has 65534 hosts - Class C
-
192-223
starts with 110
255.255.255.0/24
254 hosts - Class D
-
224-239
multi cast addresses cannt be used to address hosts - Class E
-
1111
research
240-255 - Private addresses
-
-10/8
-172.16/12
-192.168/16 -
Memorize Charts on 5-24
Private and Public IPv4 Address Decision Table -
-private needs no internet connectivity
-public- all end systems are accessible - IPv6 Datagram Structure
-
-version- 4 bit field
-traffic class- 8 bit, QoS
-flow label- 20 bit field, that labels the sequence of packets for which source requests special handling by IPv6 routers
-payload length- 16 bit, total length of data portion of the packet
-next header- 8 bit
-hop limit-8 bit field
-source address-16 octets
-destination address- 16 octets - IPv6 address scopt types
-
one to one
anycast (one to nearest)
multicast (one to many) - IPv6 address types-
-
-link local address- cannot leave link, V6 will not route link address similar to private addresses in V4
-site local address-used for sites that dont have global prefix- private interior set of V4 addresses, cant be sent out to internet - Link Local Address Header
- FE80::/10
- Site Local Address Header
- FEC0::/10