Routing services -

Routing services


Intelligent Information Network (IIN)

    The IIN encompasses the following features:

  • Integration of networked resources and information assets that have been largely unlinked The modern converged networks with integrated voice, video, and data require that IT departments (and other departments that were traditionally responsible for other technologies) more closely link the IT infrastructure with the network.
  • Intelligence across multiple products and infrastructure layers — The intelligence built in to each component of the network is extended networkwide and applies end to end.
  • Active participation of the network in the delivery of services and applications — With added intelligence, the IIN makes it possible for the network to actively manage, monitor, and optimize service and application delivery across the entire IT environment.

Cisco Service-Oriented Network Architecture (SONA)

    The SONA framework outlines the following three layers:

  • Networked infrastructure layer - The IT resources include servers, storage, and clients. The networked infrastructure layer represents how these resources exist in different places in the network, including the campus, branch, data center, wide-area network (WAN), metropolitan-area network (MAN), and with the teleworker.
  • Interactive services layer - Enables efficient allocation of resources to applications and business processes This layer includes these services:
  1. Voice and collaboration services
  2. Mobility services
  3. Computer services
  4. Application networking services
  5. Network infrastructure virtualization
  6. Services management
  7. Storage services
  8. Security and identity services
  • Application layer - Includes business applications and collaboration applications.

Cisco Enterprise Composite Network Model

  • Enterprise Campus - This functional area contains the modules required to build ahierarchical, highly robust campus network. Access, distribution, and core principlesare applied to these modules appropriately.
  • Enterprise Edge - This functional area aggregates connectivity from the variouselements at the edge of the enterprise network, including to remote locations, theInternet, and remote users.
  • Service Provider Edge - This area is not implemented by the organization; instead,it is included to represent connectivity to service providers such as Internet serviceproviders (ISPs), WAN providers, and the public switched telephone network (PSTN).
  • PSTN - Represents all nonpermanent connections, including via analog phone, cellular phone, and Integrated Services Digital Network (ISDN).

Creating, Documenting, and Executing an Implementation Plan

    Creating an Implementation Plan :
Step 1. Identify customer requirements
Step 2. Characterize the existing network and sites
Step 3. Design the network topology and solutions:
Step 1. Plan the implementation
Step 2. Implement and verify the design
Step 3. Monitor and optionally redesign

    The implementation plan documentation should include the following:

  • Network information
  • Tools required
  • Resources required
  • Implementation plan tasks
  • Verification tasks
  • Performance measurement and results
  • Screen shots and photographs, as appropriate

    After gathering this information, all details and requirements are documented, including the following:

  • A list of existing and required equipment
  • The current and required software versions on the equipment
  • The network topology (physical and logical)
  • The design documentation
  • The current configurations, including IP addressing, summarization, routing, QoS, security, and so forth
  • Current link utilization and metrics
  • Site-specific requirements, including IP addressing, software required, topology changes, routing protocol requirements, QoS, security, and so forth

IP Routing Overview

Configuring a Static Route:

ip route prefix mask {address | interface [address]} [dhcp] [distance] [name next-hop-name] [permanent track number] [tag tag]

prefix mask    The IP network and subnet mask for the remote network to be entered into the IP routing table.
address    The IP address of the next hop that can be used to reach the destination network.
interface    The local router outbound interface to be used to reach the destination network.
dhcp    Enables a Dynamic Host Configuration Protocol (DHCP) server(Optional) to assign a static route to a default gateway (option 3).
distance    The administrative distance to be assigned to this route. (Optional) name next- (Optional) Applies a name to the specified route.
hop-name    permanent Specifies that the route will not be removed from the routing (Optional) table even if the interface associated with the route goes down.
track number    Associates a track object with this route. Valid values for the (Optional) number argument range from 1 to 500.
tag tag    A value that can be used as a match value in route maps.(Optional)

On-Demand Routing (ODR)

    ODR is applicable in a hub-and-spoke topology only. ODR uses the Cisco Discovery Protocol (CDP) to carry network information between spoke (stub) routers and the hub router. ODR provides IP routing information with minimal overhead compared to adynamic routing protocol and requires less manual configuration than static routes.

Configuring ODR:

    On the stub router, there must be no IP routing protocol configured. ODR is configured on the hub router using the router odr global configuration command. ODR can also be tuned with optional commands, including using a distribute list to control the network information that is recognized through ODR, and adjusting the ODR timers with the timers basic router configuration command. CDP updates are sent as multicasts. CDP uses Subnetwork Access Protocol (SNAP) frames. CDP updates are sent every 60 seconds by default. You can adjust the timers with the cdp timer global configuration command. You can verify CDP settings by using the show cdp interface command.


    RIPv1 is described in RFC 1058, Routing Information Protocol. Its key characteristics include the following:

  • Hop count is used as the metric for path selection.
  • The maximum allowable hop count is 15.
  • Routing updates are broadcast every 30 seconds by default. Because it is a distance vector routing protocol, updates are sent even if no change has occurred.
  • RIP can load balance over as many as 16 equal-cost paths (4 paths by default).
  • It has no authentication support.
  • broadcast address

    RIPv2 is a classless distance vector routing protocol defined in RFC 1721, RIP Version 2 Protocol Analysis; RFC 1722, RIP Version 2 Protocol Applicability Statement; and RFC 2453, RIP Version 2.

  • support VLSM and discontiguous subnets.
  • automatically summarizes routes on classful network boundaries
  • multicast address to advertise to other RIPv2 routers.
  • IP sends the packet to the User Datagram Protocol (UDP) process, and UDP checks to see whether RIP port 520 is available. Most PCs and servers do not have any process running on this port and discard the packet.
  • RIP can fit up to 25 networks and subnets in each update, and updates are dispatched every 30 seconds.
  • message-digest or clear-text authentication.

    Router A is running RIPv2, and Router C is running RIPv1. Router B runs both versions of RIP. Notice that the ip rip send version 1 and ip rip receive version 1 commands are required only on interface Serial 0/0/3 of Router B, because RIPv2 is configured as the primary version for all interfaces. The Serial 0/0/3 interface has to be manually configured to support RIPv1 so that it can connect correctly with Router C.

    Commands used to verify RIP include the show ip route command to examine the IP routing table, and the show ip rip database command to display summary address entries in the RIP routing database entries if relevant child routes are being summarized.

Administrative Distance

    Route Source Default Administrative Distance

Connected interface 0
Static route out an interface between 0 and 1
Static route to a next-hop address 1
EIGRP summary route 5
External BGP 20
Internal EIGRP 90
IGRP 100
OSPF 110
IS-IS 115
RIPv1, RIPv2 120
Exterior Gateway Protocol (EGP) 140
ODR 160
External EIGRP 170
Internal BGP 200
Unreachable 255

IP Routing Protocol Comparisons

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