The command you use to add a static route to a routing table:

Command :

ip route [destination_network] [mask] [next-hop_address or exitinterface [administrative_distance] [permanent]

This list describes each command in the string:

ip route :    The command used to create the static route.

destination_network :  The network you’re placing in the routing table.

mask :   The subnet mask being used on the network.

Next-Hop Address :   The address of the next-hop router that will receive the packet and forward it to the remote network. This is a router interface that’s on a directly connected network. You must be able to ping the router interface before you add the route. If you type in the wrong next-hop  the address, or the interface to that router is down, static route shows up in the router’s configuration, but not in the routing table.
                    

Exitinterface :    You can use this in place of the next-hop address if you want, but it’s got to   
                            be on a point-to-point link, like a WAN. This command won’t  work on a
                            LAN like Ethernet. By default, static routes have an administrative
                            distance of 1.
                  
Administrative_Distance :    By default, static routes have an administrative distance of 1. You
                                               can change the default value by adding an administrative weight
                                               at the end of the Command.                          
                     

Permanent :    If the interface is shut down or the router can’t communicate to the next-hop
                        router, the route is automatically discarded from the routing table. Choosing
                        the permanent option keeps the entry in the routing table no matter
                        what happens.

Cisco Router Debug Commands

Requirement	Cisco Command
Enable debug for RIP	debug ip rip
Enable summary IGRP debug information	debug ip igrp events
Enable detailed IGRP debug information	debug ip igrp transactions
Debug IPX RIP	debug ipx routing activity
Debug IPX SAP	debug IPX SAP
Enable debug for CHAP or PAP	debug ppp authentication
Switch all debugging off	no debug all undebug all

Cisco Router Copy Commands

 

Requirement	Cisco Command
Save the current configuration from DRAM to NVRAM	copy running-config startup-config
Merge NVRAM configuration to DRAM	copy startup-config running-config
Copy DRAM configuration to a TFTP server	copy runing-config tftp
Merge TFTP configuration with current router configuration held in DRAM	copy tftp runing-config
Backup the IOS onto a TFTP server	copy flash tftp
Upgrade the router IOS from a TFTP server	copy tftp flash

Cisco Router Basic Operations

Requirement	Cisco Command
Enable	Enter privileged mode
Return to user mode from privileged	disable
Exit Router	Logout or exit or quit
Recall last command	up arrow or
Recall next command	down arrow or
Suspend or abort	and and 6 then x
Refresh screen output
Compleat Command	TAB

Cisco Router Show Commands

Requirement	Cisco Command
View version information	show version
View current configuration (DRAM)	show running-config
View startup configuration (NVRAM)	show startup-config
Show IOS file and flash space	show flash
Shows all logs that the router has in its memory	show log
View the interface status of interface e0	show interface e0
Overview all interfaces on the router	show ip interfaces brief
View type of serial cable on s0	show controllers 0 (note the space between the 's' and the '0')
Display a summary of connected cdp devices	show cdp neighbor
Display detailed information on all devices	show cdp entry *
Display current routing protocols	show ip protocols
Display IP routing table	show ip route
Display access lists, this includes the number of displayed matches	show access-lists
Check the router can see the ISDN switch	show isdn status
Check a Frame Relay PVC connections	show frame-relay pvc
show lmi traffic stats	show frame-relay lmi
Display the frame inverse ARP table	show frame-relay map

Cisco Router Configuration Commands

Requirement	Cisco Command
Set a console password to cisco	Router(config)#line con 0 Router(config-line)#login Router(config-line)#password cisco
Set a telnet password	Router(config)#line vty 0 4 Router(config-line)#login Router(config-line)#password cisco
Stop console timing out	Router(config)#line con 0 Router(config-line)#exec-timeout 0 0
Set the enable password to cisco	Router(config)#enable password cisco
Set the enable secret password to peter. This password overrides the enable password and is encypted within the config file	Router(config)#enable secret peter
Enable an interface	Router(config-if)#no shutdown
To disable an interface	Router(config-if)#shutdown
Set the clock rate for a router with a DCE cable to 64K	Router(config-if)clock rate 64000
Set a logical bandwidth assignment of 64K to the serial interface	Router(config-if)bandwidth 64 Note that the zeroes are not missing
To add an IP address to a interface	Router(config-if)#ip addr 10.1.1.1 255.255.255.0
To enable RIP on all 172.16.x.y interfaces	Router(config)#router rip Router(config-router)#network 172.16.0.0
Disable RIP	Router(config)#no router rip
To enable IRGP with a AS of 200, to all interfaces	Router(config)#router igrp 200 Router(config-router)#network 172.16.0.0
Disable IGRP	Router(config)#no router igrp 200
Static route the remote network is 172.16.1.0, with a mask of 255.255.255.0, the next hop is 172.16.2.1, at a cost of 5 hops	Router(config)#ip route 172.16.1.0 255.255.255.0 172.16.2.1 5
Disable CDP for the whole router	Router(config)#no cdp run
Enable CDP for he whole router	Router(config)#cdp run
Disable CDP on an interface	Router(config-if)#no cdp enable

EIGRP Short Notes

Name: EIGRP
Long Name: Enhanced Interior Gateway Routing Protocol

Supported Protocols: IP, IPX, Appletalk

Standard: Cisco Proprietary

Transport Protocol: IP
Routing Protocol Type: Hybrid
Algorithm: DUAL

Hello Timers: 5 seconds (high speed links) 60 seconds (wan links 1.5mb and lower)
Dead Timers: 15 seconds(high speed links) 180 seconds (wan links 1.5mb and lower)
EIGRP Active Timer: 3 minutes

Neighbor Discovery Type: Auto (multicast/unicast)
Multicast IP: 224.0.0.10

Internal AD: 90

External AD: 170

Route Summarization: Yes (auto by default)

RTP: Reliable Transport Protocol

EIGRP Protocol Messages:
HELLO
UPDATE (sent reliably via RTP)
QUERY (sent reliably via RTP)
REPLY (sent reliably via RTP)
ACK (acknowledgement)

EIGRP Update Message Content:
PREFIX
PREFIX LENGTH
METRIC: Bandwidth, Delay, Reliability and Load
OTHER ITEMS: MTU & Hop Count

Metric is calculated as follows:
Metric = 256 * ((10^7 / lowest bandwidth in path) + Cumulative Delay)

Metric with K value weights:
Metric = 256*((K1*Bw) + (K2*Bw)/(256-Load) + K3*Delay)*(K5/(Reliability + K4)))

EIGRP Load Balancing Default: Maximum Paths 4

Feasible Distance (FD): Metric based on local route to destination metric
Reported Distance (RD): Metric based on the neighbors metric to the destination metric
Successor Route: Lowest FD to the destination
Feasible Successor: Backup to destination if feasibility condition is met
Feasibility Condition: If a non-successor route’s RD is less than the FD, the route is a feasible successor

EIGRP Stub Options:
Connected: Advertise connected routes for interfaces matched with the network command
Summary: Advertise auto-summarized or manually configured summary routes
Redistributed: Advertise routes learned from configured redistribution
Receive-only: No routes are advertised
Static: Advertise static routes but must be used with the “redistribute static” command

2: Detailed Information

EIGRP Description:
EIGRP is a Cisco proprietary protocol primarily used on private networks. EIGRP is considered a hybrid distance vector protocol as it shares several attributes from distance vector and link state protocols. EIGRP used an automatic discovery process by sending EIGRP hello messages to the multicast address 224.0.0.10. EIGRP operates using three main tables: Topology Table, Routing Table and the Neighbor Table. Once neighbors have been discovered, EIGRP shares its entire topology table with its neighbor similar to that of a typical distance vector protocol. Local routers perform DUAL to place the best loop free routes into the routing table. Updates are sent using RTP (reliable transport protocol) for data exchange. EIGRP uses two messages as part of the update process (update & ACK).

EIGRP Update Process:
1. When two routers discover each other they exchange full topology table updates.
2. After the full topology (all prefixes) has been exchanged with a neighbor the updates are stopped, there is not a re-aging process and the topology table is not re-sent.
3. If a change occurs, a partial update is sent containing changed information
4. If neighbors fail and re-establish, the full topology table is re-sent thus repeating the cycle

Note: EIGRP Utilizes the split horizon rule, updates for prefixes will not be sent out via the same interface in which they were learned.

What triggers an EIGRP update?
Metric change
Link failure
Link Recovery
Other neighbors learn new prefixes

EIGRP Metric Information:
The EIGRP update process includes metrics for calculation for best routes. EIGRP uses bandwith, delay, reliability and load. By default, only bandwidth and delay are used. Both of these metrics are set via an interface command. Bandwidth is set to a default value of 1544 for T1 serial interfaces and auto learns bandwidth on higher speed links. Delay can be set to manipulate the routing metric for manual control of best path. By default EIGRP routing updates utilize up to 50% of the bandwidth of the circuit, because of this it is important the bandwidth on the interface is set correctly. EIGRP metrics weights can be added and are represented as “K” values.

Metric is calculated as follows:
Metric = 256 * ((10^7 / lowest bandwidth in path) + Cumulative Delay)

K Values Metric:
EIGRP metrics weights can be added and are represented as “K” values. K values can be changed per router but k values MUST match on each router in order to establish neighbor relationships.

Metric with K value weights:
EIGRP Metric = 256*((K1*Bw) + (K2*Bw)/(256-Load) + K3*Delay)*(K5/(Reliability + K4)))

EIGRP Load Balancing:
By default, EIGRP will load balance up for 4 equal cost paths. This is set with the “maximum-paths” EIGRP sub command. Up to 16 maximum paths can be set. EIGRP’s metric calculation is very detailed and it can be difficult to ensure all metrics are equal. The EIGRP variance can be used to tell the IOS that metrics within a certain value multiplier can be treated equal even if they are not an exact match. The variance multiplier can be set between 1 and 128.

An example of variance is as follows:

Best route through Serial0: 500300
Secondary route through Serial1: 600300

These two routes would not load balance, but with a variance of 2 as long as the secondary route is under the primary routes metric x 2 it would be treated equal. In this case, 500300 x 2 = 1000600 and since the secondary route of 600300 is smaller, the router would then load balance traffic for that route through S0 and S1.

EIGRP Route Types and Feasibility Condition:
As EIGRP builds its routing tables, a computation is performed called DUAL. Routes with the lowest metric are placed into the routing table. These routes are called successor routes. Due to CPU constraints and the query process routers constantly performing DUAL could introduce stability and convergence concerns. A built-in method of combatting this is by utilizing backup routes in that if the successor route is down, a backup route can be used in its place without the need for DUAL calculation. This backup route is called a feasible successor. How does a route become a feasible successor? It must meet feasibility condition and a router can have multiple feasible successors. When the successor fails, the next best feasible successor quickly become the successor and new feasible successors are calculated based on the new feasibility condition.

EIGRP Terms:
Feasible Distance (FD): Metric based on local route to destination metric
Reported Distance (RD): Metric based on the neighbors metric to the destination metric
Successor Route: Lowest FD to the destination
Feasible Successor: Backup to destination if feasibility condition is met
Feasibility Condition: If a non-successor route’s RD is less than the FD, the route is a feasible successor

EIGRP Convergence:
When EIGRP loses the successor route it looks for a feasible successor (FS). IF no FS is present meaning non-successor routes do not meet feasibility condition the route will perform DUAL. This process will attempt to discover a loop-free alternative route to reach the prefix for which the successor route was lost. This process is called going active.

Going Active:
The state is changed from passive (working) to active (non-working). A query message is sent to every neighbor except the neighbor with the failed route. The query message asks the neighbor if a loop-free route exists and if it does it will reply with an EIGRP reply message saying it does and not forward the query any further. If loop free route does NOT exist the query is forwarded and it will wait for a response before sending an EIGRP reply to the original requestor. When the original router that sent the query receives all the responses back, a new route is confirmed to be loop-free.

Stuck in Active:
When a router does not receive an EIGRP reply to a query within 3 minutes the route will become stuck in active (SIA). When a route is SIA the router is assumed to also be failed thus the neighbor relationship is reset and the learning process will start over again. In IOS version 12.2 or higher, a second SIA message is sent half-way through the active timer (90 seconds) sending a second request (SIA Query). This helps prevent the route from going SIA in the event the neighbor relationship is still established but a response was not received.

Note: Stuck in Active routes can be very harmful to the health of an EIGRP infrastructure, it is important to limit the SIA query range and design the network with the intention of limiting SIA routes.

Limiting the Query Range:
There are two main ways to limit the EIGRP query range:

Network Summarization
EIGRP Stub Networks

When a hub router is advertising networks via a summary, it will automatically respond on behalf of the neighbors for the routes in the summary advertisement. Therefore EIGRP query messages will never be forwarded past routers that are summarizing prefixes that would normally receive a query.
This same logic is performed for hub routers connected to EIGRP stubs, the hub routers answer on behalf of the stubs.

Note: EIGRP queries can be extended beyond the autonomous system, it is a common misconception that query ranges can be limited by splitting up EIGRP infrastructure through multiple AS and redistribution.

EIGRP Stub Networks:
A branch router should be configured as an EIGRP stub. There is no need for a branch router with a single EIGRP neighbor to advertise EIGRP learned routes from one neighbor to others. By default stub routers will only advertise connected and manually configured summary routers to their neighbor (hub).

EIGRP Stub Options:
Connected: Advertise connected routes for interfaces matched with the network command
Summary: Advertise auto-summarized or manually configured summary routes
Redistributed: Advertise routes learned from configured redistribution
Receive-only: No routes are advertised
Static: Advertise static routes but must be used with the “redistribute static” command

3: EIGRP Command Reference

EIGRP Commands/sub commands:

Enable EIGRP:
router eigrp “asn”
Example: router eigrp 10

Configure networks to advertise:
network “ip address” “wildcard mask
Example: network 192.168.1.0 0.0.0.255

Clear EIGRP neighbors:
clear ip eigrp neighbors

Static Neighbor Configuration:
neighbor “ip address” “interface”
Example: neighbor 10.1.1.2 S0

Auto Summarization:
enable (default): auto-summary
disable: no auto-summary
Example: no auto-summary

Enable EIGRP Variance:
variance “1-128” (default=1)
Example: variance 2

Configure EIGRP Active Timer:
timers active-time “minutes” (default: 3)
Disable: no timers active-time
Example: timers active-time 150

Configure K Values:
metric weights “tos” “k1” “k2” “k3” “k4” “k5”
Example: metric weights 0 2 0 1 0 0

Configure EIGRP Stub:
eigrp stub [receive only | connected | static | summary]
Example: eigrp stub connected

Enable EIGRP Logging:
eigrp log-neighbor-changes

EIGRP Interface Commands:

Configure link bandwidth used:
ip bandwidth-percent eigrp “%”
Example: ip bandwidth-percent eigrp 20

Configure EIGRP Summary Address:
ip summary-address eigrp “as” “ip address” “mask”
Example: ip summary-address eigrp 10 10.10.1.0 255.255.252.0

Changing the Hello Interval:
ip hello-interval eigrp “as” “seconds”
Example: ip hello-interval eigrp 10 15

Changing the Hold Time:
ip hold-time eigrp “as” “seconds”
Example: ip hold-time eigrp 10 45

Disable Split Horizon:
no ip split-horizon eigrp “as”
Example: no ip split-horizon eigrp 10

Show/Debug commands:

Display neighbors discovered by eigrp: show ip eigrp neigbors
Display neighbor detail (verify stub routing): show ip eigrp neighbor detail
Display the EIGRP topology table: show ip eigrp topology
Display the configured EIGRP interfaces: show ip eigrp interfaces
Display EIGRP traffic: show ip eigrp traffic
Display EIGRP routes from the IP routing table: show ip route eigrp
EIGRP Packet Debug: debug ip eigrp packet
EIGRP Neighbor Debug: debug ip eigrp neighbor

OSPF Routing Fundamentals

OSPF stands for Open Shortest Path First.

Definition: OSPF is a routing protocol used to determine the best route for delivering the packets within an IP networks. It was published by the IETF to serve as an Interior Gateway Protocol replacing RIP. The OSPF specification is published as Request For Comments (RFC) 1247.

Note that OSPF is a link-state routing protocol, whereas RIP and IGRP are distance-vector routing protocols. Routers running the distance-vector algorithm send all or a portion of their routing tables in routing-update messages to their neighbors.

OSPF sends link-state advertisements (LSAs) to all other routers within the same area. Information on attached interfaces, metrics used, and other variables is included in OSPF LSAs. OSPF routers  use the SPF (Shortest Path First) algorithm to calculate the shortest path to each node. SPF algorithm is also known as Dijkstra algorithm.
Advantages of OSPF

    * OSPF is an open standard, not related to any particular vendor.
    * OSPF is hierarchical routing protocol, using area 0 (Autonomous System) at the top of the hierarchy.
    * OSPF uses Link State Algorithm, and an OSPF network diameter can be much larger than that of RIP.
    * OSPF supports Variable Length Subnet Masks (VLSM), resulting in efficient use of networking resources.
    * OSPF uses multicasting within areas.
    * After initialization, OSPF only sends updates on routing table sections which have changed, it does not send the entire routing table, which in turn conserves network bandwidth.
    * Using areas, OSPF networks can be logically segmented to improve administration, and decrease the size of routing tables.

Disadvantages of OSPF:

    * OSPF is very processor intensive due to implementation of SPF algorithm. OSPF maintains multiple copies of routing information, increasing the amount of memory needed.
    * OSPF is a more complex protocol to implement compared to RIP.

OSPF Networking Hierarchy:

As mentioned earlier, OSPF is a hierarchical routing protocol. It enables better administration and smaller routing tables due to segmentation of entire network into smaller areas. OSPF consists of a backbone (Area 0) network that links all other smaller areas within the hierarchy. The following are the important components of an OSPF network:

    * Areas
    * Area Border Routers
    * Backbone Areas
    * AS Boundary Routers
    * Stub Areas
    * Not-So-Stubby Areas
    * Totally Stubby Area
    * Transit Areas

ABR: Area Border Router

ASBR: Autonomous System Boundary Router

Areas: An area consists of routers that have been administratively grouped together. Usually, an area as a collection of contiguous IP subnetted networks. Routers that are totally within an area are called internal routers. All interfaces on internal routers are directly connected to networks within the area.

Within an area, all routers have identical topological databases.

Area Border Routers: Routers that belong to more than one area are called area border routers (ABRs). ABRs maintain a separate topological database for each area to which they are connected.

Backbone Area: An OSPF backbone area consists of all routers in area  0, and all area border routers (ABRs).  The backbone distributes routing information between different areas. 

AS Boundary Routers (ASBRs): Routers that exchange routing information with routers in other Autonomous Systems are called ASBRs. They advertise externally learned routes throughout the AS.

Stub Areas: Stub areas are areas that do not propagate AS external advertisements. By not propagating AS external advertisements,  the size of the topological databases is reduced on the internal routers of a stub area. This in turn reduces the processing power and the memory requirements of the internal routers.



Not-So-Stubby Areas (NSSA): An OSPF stub area has no external routes in it. A NSSA allows external routes to be flooded within the area. These routes are then leaked into other areas. This is useful when you have a non-OSPF router connected to an ASBR of a NSSA. The routes are imported, and flooded throughout the area. However, external routes from other areas still do not enter the NSSA.



Totally Stubby Area: Only default summary route is allowed in Totally Stubby Area.

Transit Areas: Transit areas are used to pass traffic from an adjacent area to the backbone. The traffic does not originate in, nor is it destined for, the transit area.
Link State Advertisements (LSAs):

It is important to know different Link State Advertisements (LSAs) offered by OSPF protocol.

Type 1: Router link advertisements generated by each router for each area it belongs to. Type 1 LSAs are flooded to a single area only.

Type 2: Network link advertisements generated by designated routers (DRs) giving the set of routers attached to a particular network. Type 2 LSAs are flooded to the area that contains the network.

Type 3/4: These are summary link advertisements generated by ABRs describing inter-area routes. Type 3 describes routes to networks and is used for summarization. Type 4 describes routes to the ASBR.

Type 5: Generated by the ASBR and provides links external to the Autonomous System (AS). Type 5 LSAs are flooded to all areas except stub areas and totally stubby areas.

Type 6: Group membership link entry generated by multicast OSPF routers.

Type 7: NSSA external routes generated by ASBR. Only flooded to the NSSA. The ABR converts LSA type 7 into LSA type 5 before flooding them into the backbone (area 0).

640-802 CCNA

Cisco Certified Network Associate Exam
Exam Number:     640-802
Associated Certifications:     CCNA
Duration:     90 minutes (50-60 questions)
Available Languages:     English

Exam Description
The 640-802 Cisco Certified Network Associate (CCNA) is the composite exam associated with the Cisco Certified Network Associate certification. Candidates can prepare for this exam by taking the Interconnecting Cisco Networking Devices Part 1 (ICND1) v1.0 and the Interconnecting Cisco Networking Devices Part 2 (ICND2) v1.0 courses. This exam tests a candidate's knowledge and skills required to install, operate, and troubleshoot a small to medium size enterprise branch network. The topics include connecting to a WAN; implementing network security; network types; network media; routing and switching fundamentals; the TCP/IP and OSI models; IP addressing; WAN technologies; operating and configuring IOS devices; extending switched networks with VLANs; determining IP routes; managing IP traffic with access lists; establishing point-to-point connections; and establishing Frame Relay connections.
Exam Topics

The following topics are general guidelines for the content likely to be included on the Cisco Certified Network Associate exam. However, other related topics may also appear on any specific delivery of the exam. In order to better reflect the contents of the exam and for clarity purposes, the guidelines below may change at any time without notice.
Describe how a network works

    * Describe the purpose and functions of various network devices
    * Select the components required to meet a network specification
    * Use the OSI and TCP/IP models and their associated protocols to explain how data flows in a network
    * Describe common networked applications including web applications
    * Describe the purpose and basic operation of the protocols in the OSI and TCP models
    * Describe the impact of applications (Voice Over IP and Video Over IP) on a network
    * Interpret network diagrams
    * Determine the path between two hosts across a network
    * Describe the components required for network and Internet communications
    * Identify and correct common network problems at layers 1, 2, 3 and 7 using a layered model approach
    * Differentiate between LAN/WAN operation and features

Configure, verify and troubleshoot a switch with VLANs and interswitch communications

    * Select the appropriate media, cables, ports, and connectors to connect switches to other network devices and hosts
    * Explain the technology and media access control method for Ethernet networks
    * Explain network segmentation and basic traffic management concepts
    * Explain basic switching concepts and the operation of Cisco switches
    * Perform and verify initial switch configuration tasks including remote access management
    * Verify network status and switch operation using basic utilities (including: ping, traceroute, telnet, SSH, arp, ipconfig), SHOW & DEBUG commands
    * Identify, prescribe, and resolve common switched network media issues, configuration issues, auto negotiation, and switch hardware failures
    * Describe enhanced switching technologies (including: VTP, RSTP, VLAN, PVSTP, 802.1q)
    * Describe how VLANs create logically separate networks and the need for routing between them
    * Configure, verify, and troubleshoot VLANs
    * Configure, verify, and troubleshoot trunking on Cisco switches
    * Configure, verify, and troubleshoot interVLAN routing
    * Configure, verify, and troubleshoot VTP
    * Configure, verify, and troubleshoot RSTP operation
    * Interpret the output of various show and debug commands to verify the operational status of a Cisco switched network
    * Implement basic switch security (including: port security, trunk access, management vlan other than vlan1, etc.)

Implement an IP addressing scheme and IP Services to meet network requirements in a medium-size Enterprise branch office network

    * Describe the operation and benefits of using private and public IP addressing
    * Explain the operation and benefits of using DHCP and DNS
    * Configure, verify and troubleshoot DHCP and DNS operation on a router.(including: CLI/SDM)
    * Implement static and dynamic addressing services for hosts in a LAN environment
    * Calculate and apply an addressing scheme including VLSM IP addressing design to a network
    * Determine the appropriate classless addressing scheme using VLSM and summarization to satisfy addressing requirements in a LAN/WAN environment
    * Describe the technological requirements for running IPv6 in conjunction with IPv4 (including: protocols, dual stack, tunneling, etc).
    * Describe IPv6 addresses
    * Identify and correct common problems associated with IP addressing and host configurations

Configure, verify, and troubleshoot basic router operation and routing on Cisco devices

    * Describe basic routing concepts (including: packet forwarding, router lookup process)
    * Describe the operation of Cisco routers (including: router bootup process, POST, router components)
    * Select the appropriate media, cables, ports, and connectors to connect routers to other network devices and hosts
    * Configure, verify, and troubleshoot RIPv2
    * Access and utilize the router to set basic parameters.(including: CLI/SDM)
    * Connect, configure, and verify operation status of a device interface
    * Verify device configuration and network connectivity using ping, traceroute, telnet, SSH or other utilities
    * Perform and verify routing configuration tasks for a static or default route given specific routing requirements
    * Manage IOS configuration files. (including: save, edit, upgrade, restore)
    * Manage Cisco IOS
    * Compare and contrast methods of routing and routing protocols
    * Configure, verify, and troubleshoot OSPF
    * Configure, verify, and troubleshoot EIGRP
    * Verify network connectivity (including: using ping, traceroute, and telnet or SSH)
    * Troubleshoot routing issues
    * Verify router hardware and software operation using SHOW & DEBUG commands
    * Implement basic router security

Explain and select the appropriate administrative tasks required for a WLAN

    * Describe standards associated with wireless media (including: IEEE WI-FI Alliance, ITU/FCC)
    * Identify and describe the purpose of the components in a small wireless network. (Including: SSID, BSS, ESS)
    * Identify the basic parameters to configure on a wireless network to ensure that devices connect to the correct access point
    * Compare and contrast wireless security features and capabilities of WPA security (including: open, WEP, WPA-1/2)
    * Identify common issues with implementing wireless networks. (Including: Interface, missconfiguration)

Identify security threats to a network and describe general methods to mitigate those threats

    * Describe today's increasing network security threats and explain the need to implement a comprehensive security policy to mitigate the threats
    * Explain general methods to mitigate common security threats to network devices, hosts, and applications
    * Describe the functions of common security appliances and applications
    * Describe security recommended practices including initial steps to secure network devices

Implement, verify, and troubleshoot NAT and ACLs in a medium-size Enterprise branch office network

    * Describe the purpose and types of ACLs
    * Configure and apply ACLs based on network filtering requirements.(including: CLI/SDM)
    * Configure and apply an ACLs to limit telnet and SSH access to the router using (including: SDM/CLI)
    * Verify and monitor ACLs in a network environment
    * Troubleshoot ACL issues
    * Explain the basic operation of NAT
    * Configure NAT for given network requirements using (including: CLI/SDM)
    * Troubleshoot NAT issues

Implement and verify WAN links

    * Describe different methods for connecting to a WAN
    * Configure and verify a basic WAN serial connection
    * Configure and verify Frame Relay on Cisco routers
    * Troubleshoot WAN implementation issues
    * Describe VPN technology (including: importance, benefits, role, impact, components)
    * Configure and verify a PPP connection between Cisco routers

Recommended Training
The following courses are the recommended training for this exam.

    * Interconnecting Cisco Networking Devices Part 1 (ICND1) v1.0
    * Interconnecting Cisco Networking Devices Part 2 (ICND2) v1.0

IGRP (Interior Gateway Routing Protocol)

The Interior Gateway Routing Protocol (IGRP) is a Cisco proprietary protocol. Like RIP, IGRP is a distance-vector interior routing protocol. However, unlike RIP, IGRP can be used in larger autonomous systems due to its large maximum hop-count limit of 255, compared to RIP's maximum hop count of 16.

IGRP uses bandwidth and delay of the line by default as metric for determining the best route to an internetwork. This is called a composite metric. Reliability, load and maximum transmission unit (MTU) can also be used, although they are not used by default.

To control performance IGRP uses different kind of timers:

Update Timers specifies how frequently IGRP routing messages will be sent. The default is 90 seconds.

Invalid Timer specifies how long a router should wait in the absence of a routing-update message of a specific route before declaring it invalid. The default is three times the Update timer, 270 seconds.

Holddown Timer specifies the holddown period. The default is three times the update timer plus 10 seconds, 280 seconds.

Flush Timer indicates how much time should pass before an IGRP route is flushed from the routing table. The default is seven times the routing update period, 630 seconds.

IGRP Configurations

Configuring IGRP is similar to configuring RIP in that after the router command you must specify only directly connected (system routes) networks. The only difference is in the command to enable the routing protocol. You must specify an AS number when enabling IGRP. The AS number parameter specifies the autonomous system number that is supported by this IGRP process and allows multiple IGRP processes to run on a single router. The AS number can be between 1 and 65,655.

For example:
RTR(config)# router igrp 10
RTR(config-router)# network 200.40.0.0
RTR(config-router)# network 200.30.0.0

Monitoring and Verifying IGRP

Command                                      Description

Show ip protocols                    Shows routing protocol parameters and current timer values
Debug ip igrp transactions     Issues log messages with details of the IGRP updates.
Debug ip igrp events               Issues log messages for each igrp updates
Ping                                           Sends and receive ICMP echo messages to verify connectivity
trace                                          Sends a series of ICMP echoes with increasing TTL value
Show ip route                          Shows routing protocol parameters and current timer values

RIP (Routing Information Protocol)

RIP is a true distance vector routing protocol. It sends the complete routing table out to all other active interfaces every 30 seconds. RIP uses Hop Count as it's only metric. The maximum number of hops in a RIP network is 15, one hop is a directly connected network, and 16 hops is an unreachable network.

RIP v1 uses only classful routing. RIP v2 uses classless routing.

RIP uses three different kinds of timers to regulate its performance:

Route Update timer sets the interval (30 seconds) between periodic routing updates in which the routers sends a complete copy of its routing table out to all neighbors.

Route Invalid timer determines the length of time that must expire (90 seconds) before a router determines that a route has become invalid.

Router Flush timer sets that time between a route becoming invalid and its remove from the routing table (240 seconds).

RIP Configurations

RIP is very simple to configure. All you need to do is enable RIP and add each network that uses RIP. However, RIPv2 has a few more possible commands; you can use two of them: version and no auto-summary.

Because the router will by default use RIPv1, you must use the version command to tell the router to use RIPv2. In addition, by default RIPv2 will summarize major networks across boundaries. Use the no auto-summary command to stop summarization.

RIPv1 Configuration Example

Router A (config)#router rip
Router A (config_router)#network 208.28.3.0
Router A (config_router)#network 192.38.56.0

Router B (config)#router rip
Router B (config-router)#network 134.80.0.0
Router B (config-router)#network 192.38.56.0
Router B (config-router)#network 192.38.57.0
Router B (config-router)#network 192.38.58.0

Router C (config)#router rip
Router C (config-router)#network 192.38.58.0
Router C (config-router)#network 208.28.1.0

Router D (config)#router rip
Router D (config-router)#network 192.38.57.0
Router D (config-router)#network 208.28.2.0

Monitoring and Verifying RIP

Command                       Description

Show ip protocols     Shows the entire routing table

Show ip route                 Shows routing protocol parameters and current timer values

Debug ip rip                 Issues log message for each RIP update

Ping                            Sends and receive ICMP echo messages to verify connectivity

Trace                            Sends a series of ICMP echoes with increasing TTL value

Routing Concepts

Routing

Routing is the process of forwarding packets from one network to another. All the information needed for a router to forward packets to a hop (router/relay device) can be found in the router's routing table.

Static Routing

Static routing occurs when you manually add routes in each router's routing table. Static routes are routes that are administratively configured in routers. They are typically used when dynamic protocols are either unnecessary or unwanted.
Static routing has following benefits:

    * There is no overhead on the routers CPU
    * There is no bandwidth usage between routers, which mean u could possibly save money on WAN links

Static routing has following disadvantages:

    * The administrator must really understand the internetwork and how each router is connected in order to configure routes properly
    * If a network is added to internetwork, the administrator has to add a route to it on all routers

Default Routing

Default routing useto send packets with a remote destination network not in the routing table to the next-hop router. You can only use default routing on stub networks-those with only one exit path out of the network.

Dynamic Routing

Dynamic routing is the process of using protocols to find and update routing tables on routers and to maintain a loop-free, single path to each network. This is easier than using static routing but it will cost u in terms of router CPU processes and bandwidth on the network links.

There are two types of dynamic routing protocols used in internetwork.Interior Gateway Protocols (IGP) and Exterior Gateway Protocols (EGP). IGP routing protocol are used to exchange routing information with routers in the same autonomous system (AS). An AS is a collection of network under a common administrative domain. EGP's are used to communicate between ASes. BGP is an example of EGP.

Link State versus Distance Vector Routing Protocols

In determining the best route to a destination, different routing protocols use a number of different measurements. These measurements are called metrics. Each routing protocol uses one or more metric to calculate the best route to a particular destination. The most common metrics include path length (hop count), reliability, delay, bandwidth, load, and financial cost of a link.

Another major difference between routing protocols is how they handle updating each other with current information. There are many methods of doing this. Given these major differences, routing protocols are broken into two main categories: Distance Vector and Link State.

Distance Vector protocols include RIP and IGRP. They send their entire routing tables out in all directions at regularly scheduled intervals.

Link State protocols are more advanced than distance vector protocols because, unlike distance vector, they do not send periodic routing updates. Link State protocols include OSPF, NLSP, BGP, and IS-IS.

They send partial routing tables (of their own networks) to everyone and then send updates when necessary.

Classful Versus Classless Routing

The basic definition of classful routing is that subnet mask information is not carried within the routine, periodic routing updates. This means that every interface and host on the network must use the same subnet mask. In other words, a classful routing protocol abides strictly to the bit boundaries of the IP address classes. For example, the 10.0.0.0 network-a Class A network-cannot be advertised as anything Other than a route to 10.0.0.0, since the default network mask of a Class A network is 255.0.0.0. In other words, VLSMs are effectively useless. This is because the routing update packet has no field for subnet mask, so the default mask according to the class is assumed. Classful routing protocols include RIP v1 and IGRP.

Classless routing protocols include the subnet mask information when an update is sent. This allows different length subnet masks to be used on the network called Variable Length Subnet Masks (VLSM).

Default Administrative Distances

Administrative distances are used to rate the trustworthiness of routing information received on a router from a neighbor router. If a router learns of different types of routes to the same destination (statically configured or advertised via a dynamic routing protocol), it must select which route to include in its routing table. Typically, only one route to a specific destination (same address and mask) is in a router's routing table. One method of route "selection" is accomplished by comparing the administrative distance of all the routes to the same destination. Administrative Distance is a value, which rates the reliability of the source of the route. If the source that provides a route to a router is considered to be less reliable-less trustworthy-it receives a higher administrative distance value. The lowest administrative distance becomes the preferred route entered in the routing table. Administrative distance values range from 0 to 255. If desired, the administrator can configure administrative distances so that the default administrative distance is not used.

Routing Fundamentals

To begin, you need to understand the routing function itself and what happens during the
process. In this section, I show you how a router makes its decisions about where and how
to send data. You’ll learn about the information that a router needs in order to make these
decisions. Then you’ll delve into the ways that the router gets this information—both static
routing (you, as the administrator, will give this to the router) and dynamic routing. You will
look at administrative distance and some of the functions that help a router determine which
routing information is the best. You will see how dynamic routing protocols are categorized
and the features each provides.

Basic Routing :

At this point we have discussed connecting hosts and wiring up the network for use. With
routing, you go beyond the network connections. You have figure out how the router is
going to pass data between subnets. Start off by thinking about the information a router
needs to make a routing decision. Routers care only about networks when they are routing,
not about individual host IP addresses. Every router must know about every destination network to which it can send data. If a router has a packet to route but the destination network
is not in its routing table, then the packet will be dropped.

The information that a router needs to route are:

• NN Destination address
• NN Possible routes to all remote networks
• NN The best route or path to a destination network
• NN Neighbor routers from which it can learn routes and send data
• NN A way to learn, update, and maintain route information

Commands For Router Modes in CISCO

Router>                             User mode
Router#                             Privileged mode
Router(config)#                 Global configuration mode
Router(config-if)#              Interface mode
Router(config-subif)#         Subinterface mode
Router(config-line)#           Line mode
Router(config-router)#       Router configuration mode

What is a Network ?

      * A Network is a connected collection of devices and end systems ,such as computers and servers, which can communicate with each other.
      * Networks carry data in many types of environments,including homes,small business, and large enterprise, there may be a number of locations that need to communicate with each other, and you can describe those locations in terms of where the workers are located.