© 2001, Cisco Systems, Inc. Policy Propagation Through BGP

© 2001, Cisco Systems, Inc.

Policy Propagation Through BGP

Policy Propagation Through BGP

© 2001, Cisco Systems, Inc. Policy Propagation Through BGP-2

ObjectivesObjectives

Upon completion of this chapter, you will be able to perform the following tasks:

• Describe the basics of the Differentiated Services QoS model

• Identify the issues of deploying DiffServ QoS model in large-scale networks

• Configure and monitor QoS Policy Propagation via BGP (QPPB)

• Describe the basics of Web Caching

• Identify the issues of deploying differentiated Web Caching in large-scale networks

• Configure and monitor Web Caching Communication Protocol (WCCP) Policy Redirection


Quality of ServiceQuality of Service

• Accelerating the deployment of network services, by enabling predictable response for application traffic and service requirements

• Best-effort IP delivery is not good enough for all applications and services. Some services or applications need:• Guaranteed bandwidth

• Low and predictable delay

• Limited bandwidth

• Requires BGP for propagation of classes of services


Web CachingWeb Caching

• Used to improve throughput and response times of frequently visited web pages

• Requires BGP for advanced web caching designs with multiple clusters of web cache devices

Large-Scale IP Quality of Service Overview

Large-Scale IP Quality of Service Overview

www.cisco.com© 2001, Cisco Systems, Inc. Policy Propagation Through BGP-5



Upon completion of this section, you will be able to perform the following tasks:

• Describe components of the Differentiated Services (DiffServ) IP QoS model

• Describe the role of IP Precedence in DiffServ model

• Describe the role of QoS group in Cisco’s QoS implementation

• List the QoS components deployed between the Service Provider and a customer

• Identify the challenges of deploying large-scale QoS solutions


QoS Conceptual ModelsQoS Conceptual Models

• Two conceptual models developed within IETF• Integrated Services (IntServ)

• Differentiated Services (DiffServ)

• IntServ model does not scale

• New IP QoS mechanisms are available in IOS to support the DiffServ model in large environments


DiffServ OverviewDiffServ Overview

• The main goal of DiffServ is to provide a scalable IP QoS framework

• Defined by IETF’s RFC2475; An architecture for DiffServ

• Complex traffic classification, marking, and conditioning is performed at network edge resulting in a per-packet Differentiated Services Code Point (DSCP)

• Core only performs ‘simple’ operations based on DSCP


Predefined DiffServ Service Classes

Predefined DiffServ Service Classes

Assured Forwarding• RFC 2597

• Guarantees bandwidth to a class

• Four standard classes

Expedited Forwarding• RFC 2598

• Guarantees the lowest possible delay

• One standard class


QoS Building Blocks within Cisco IOS

QoS Building Blocks within Cisco IOS

• Edge classification is the most difficult task in large environments

Classify

Meter

Mark Police

Forward

Classify

Meter

Mark Police Queue

InputInterface

OutputInterface

Input

Output

EDGE: DiffServ model uses complex classification on network edges (i.e. access lists)

EDGE: Marking is only performed at network edge. Based on initial classification a router can mark IP packets with DSCP, IP precedence or QoS group

CORE: Classification in the core is based on DSCP, IP precedence or QoS group

CORE: Queuing, scheduling and dropping is influenced by the simple classification


Marking of IP PacketsMarking of IP Packets

• IP precedence – high-order three bits in the Type of Service field in the IP header

• Diffserv Code Point (DSCP) – high order six bits in DS Field (RFC 2474, former ToS field)

• QoS group – internal tagging of packets in routers (requires reclassification on every hop)


Class MarkersClass Markers

Bufferheader

IP packetIP

header

IP precedence or DSCP

QoS group (information is lost once the packet leaves the router)

• IP precedence – 3 bits (8 classes)

• DSCP – 6 bits (64 classes)

• QoS group – 100 classes

IP packets in router’s memory are stored in fixed-length “buffers”

Frameheader


QoS FunctionsQoS Functions

• Guaranteeing quality of service for:• Applications (usually identified by TCP or

UDP port numbers)

• Services (usually identified by IP addresses or IP networks)

• Service providers, as the name says, provide services and can also guarantee a certain level of quality to these services


Example – Classifying Outgoing Traffic

Example – Classifying Outgoing Traffic

• Customer wants guaranteed bandwidth to and from the Internet (ISP2)

ServiceProvider

ServiceProvider

CustomerCustomer

ISP2ISP2EDGE: classification is simple – based on source interface

EDGE (and CORE): queuing and scheduling based on the marking (IP precedence or DSCP)


Example – Classifying Incoming Traffic

Example – Classifying Incoming Traffic

• Customer wants guaranteed bandwidth to and from the Internet (ISP2)

ServiceProvider

ServiceProvider

CustomerCustomer

ISP2ISP2

EDGE: classification is impossible in large networks; using access list does not scale


IP QoS Edge MechanismsIP QoS Edge Mechanisms

• Admission control and policing• Inbound Committed Access Rate (CAR) filters:

per interface, IP ACL, or MAC address

• Packet classification and marking• CAR filters or BGP-based CEF marking

• Global marking (IP precedence or DSCP field)

• Local marking (QoS group within the router)


IP QoS Core MechanismsIP QoS Core Mechanisms

Queuing• Weighted Fair Queuing (WFQ) influenced by IP

precedence

• Class-based WFQ (very fast custom queuing based on IP precedence or QoS group)

Congestion management• Weighted Random Early Detection (WRED)

influenced by IP precedence


SummarySummary

After completing this section, you should be able to perform the following tasks:

• Describe components of Differentiated Services (DiffServ) IP QoS model

• Describe the role of IP Precedence in DiffServ model

• Describe the role of QoS group in Cisco’s QoS implementation

• List the QoS components deployed between the Service Provider and a customer

• Identify the challenges of deploying large-scale QoS solutions


Review QuestionsReview Questions

• Name the two predefined DiffServ service classes

• Name some QoS mechanisms available in the IOS

• Which QoS markers are available in the IOS?

• How can we mark IP packets with the help of BGP?

BGP Driven QoS MarkingBGP Driven QoS Marking





• Describe the Cisco Express Forwarding (CEF) switching mechanism

• Describe the QoS packet classification and marking with CEF

• Describe the role of BGP in CEF-based QoS marking

• Configure QoS Policy Propagation with BGP (QPPB)

• Monitor and troubleshoot QPPB

• Deploy QPPB in large-scale BGP-based networks


QPPB RequirementsQPPB Requirements

QoS Policy Propagation through BGP requires the following:

• Cisco Express Forwarding (CEF switching)

• BGP

• Cisco 7200, 7500, or 12000

• Cisco IOS release 11.1CC, 12.0, or later


Review: Standard IP SwitchingReview: Standard IP Switching

BGP TableAddress Prefix AS-Path Communities Other attr.Next hop10.0.0.0 /8 42 13 37:121.2.3.4

... ... ... ... ......

IP RoutingTable

Address Prefix

... ...

SwitchingCache

Prefix Next-hop Outgoing interface---

/24 --- Ethernet 0

Address

1.2.3.0

Protocol

conn./8 1.2.3.410.0.0.0BGP

IP address

...ARP Cache

MAC address

...

L2 header

...10.0.0.0 /8 MAC header

1.2.3.4 0c.00.11.22.33.44


Review: CEF SwitchingReview: CEF Switching

FIB Table(CEF

Cache)


... ... ... ... ......

IP RoutingTable

Address Prefix

... ...

Next-hop Outgoing interfaceAddressProtocolBGP

ARP cache

Adjacency pointer

...

1.5.4.1 Ethernet 01.2.3.0OSPF--- Ethernet 01.5.4.0conn.

MAC address

...

IP address

...

Layer 2 header

...

AdjacencyTable

IP address

...1.5.4.1 MAC header

Prefix

/24/24

1.2.3.4 ---10.0.0.0 /8

0c.00.11.22.33.441.5.4.1

10.0.0.0 /8 1.5.4.1


CEF Switching with QoS Packet Marking

CEF Switching with QoS Packet Marking

FIB Table(CEF

Cache)


... ... ... ... ......

IP RoutingTable

Address Prefix

... ...

Next-hop Outgoing interfaceAddressProtocolBGP

ARP cache

Adjacency pointer

...

1.5.4.1 Ethernet 01.2.3.0OSPF--- Ethernet 01.5.4.0conn.

MAC address

...

IP address

...

Layer 2 header

...

AdjacencyTable

IP address

...1.5.4.1 MAC header

Prefix

/24/24

Precedence

------

QoS group

------

1.2.3.4 ---10.0.0.0 /8 3 7

BGP table map

Precedence

...

QoS group

...

0c.00.11.22.33.441.5.4.1

10.0.0.0 /8 1.5.4.1 3 7


QoS Packet Marking with CEFQoS Packet Marking with CEF

• Mark the routes in the BGP table• Use BGP communities, AS paths, IP prefixes,

or any other BGP attributes

• Set IP precedence or QoS group in IP routing table and FIB table

• Enable CEF packet marking on interface


Set IP Precedence or QoS Group in the IP Routing Table and FIB

Set IP Precedence or QoS Group in the IP Routing Table and FIB

table-map route-map-name

Router(config-router)#

• Specifies the route map used to set additional routing table attributes

route-map name permit seqset ip precedence precedenceset ip qos-group group

Router(config)#

• Specifies IP precedence and QoS group values in the routing table/FIB table entry


Enable Per-Interface Packet Marking

Enable Per-Interface Packet Marking

bgp-policy source ip-prec-map

Router(config-if)#

• Applied to packets received through this interface• Uses FIB to map packet source IP address to IP

precedence• Rewrites IP precedence in the packet

bgp-policy source ip-qos-map

Router#

• Applied to packets received through this interface• Uses FIB to map packet source IP address to QoS

group• QoS group attached to the incoming packet


Enable Per-Interface Packet Marking (cont.)

Enable Per-Interface Packet Marking (cont.)

bgp-policy destination ip-prec-map

Router(config-if)#

• Applied to packets received through this interface• Uses FIB to map packet destination IP address to IP

precedence• Rewrites IP precedence in the packet

bgp-policy destination ip-qos-map

Router#

• Applied to packets received through this interface• Uses FIB to map packet destination IP address to

QoS group• QoS group attached to the incoming packet


Monitoring and Troubleshooting QPPB

Monitoring and Troubleshooting QPPB

show ip cef [prefix] [detail]

router#

• Detailed CEF output shows the IP precedence value

Router#show ip cef 10.1.1.0 detail10.1.1.0/24, version 12, cached adjacency to Serial0/0.10 packets, 0 bytes, Precedence flash (3) via 10.3.0.2, 0 dependencies, recursive next hop 10.3.0.2, Serial0/0.1 via 10.3.0.0/30 valid cached adjacencyRouter#

Router#show ip cef 10.1.1.0 detail10.1.1.0/24, version 12, cached adjacency to Serial0/0.10 packets, 0 bytes, Precedence flash (3) via 10.3.0.2, 0 dependencies, recursive next hop 10.3.0.2, Serial0/0.1 via 10.3.0.0/30 valid cached adjacencyRouter#


Monitoring and Troubleshooting QPPB (cont.)

Monitoring and Troubleshooting QPPB (cont.)

show ip interface [interface]

router#

• Shows whether QPPB is enabled on an interface

Router#show ip interfaceSerial0 is up, line protocol is up Internet address is 10.3.0.2/30 Broadcast address is 255.255.255.255 ... Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is enabled (output ip-prec-map)

Router#show ip interfaceSerial0 is up, line protocol is up Internet address is 10.3.0.2/30 Broadcast address is 255.255.255.255 ... Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is enabled (output ip-prec-map)


IP QoS Case StudyIP QoS Case Study

• Customer in AS 73 is a Premium customer

• All packets to and from AS 73 shall be sent with precedence flash

AS 12

WAN Core

Customer(AS 73)AS 24

NAP RouterNAP Router POP Router


Step #1Distribute QoS Functions

Step #1Distribute QoS Functions

AS 12

WAN Core



Packets for AS73marked withprecedence flash

Packets from serial interface marked withprecedence flash


Step #2Select QoS Mechanisms

Step #2Select QoS Mechanisms

AS 12

WAN Core



Packets for AS73marked withprecedence flash

Packets from serial interface marked withprecedence flash

CEF-based marking

Inbound CAR filter on interface


Step #3 - Design Individual QoS Mechanisms (CEF Marking)

Step #3 - Design Individual QoS Mechanisms (CEF Marking)

AS 12

WAN Core



Mark BGP routes from AS 73with special community (12:17)

Configure community propagation

Set FIB table based onBGP community

Configure CEF packet markingfor packets coming from adjacent AS


Mark Routes Coming from AS73

Mark Routes Coming from AS73

AS 12

WAN Core



router bgp 12neighbor 1.2.3.4 remote-as 73neighbor 1.2.3.4 route-map Premium in!route-map Premium permit 10set community 12:17 additive


Configure Community Propagation

Configure Community Propagation

AS 12

WAN Core



router bgp 12neighbor 2.3.4.5 remote-as 12neighbor 2.3.4.5 send-community


Set FIB Table Based on BGP Community

Set FIB Table Based on BGP Community

AS 12

WAN Core



router bgp 12table-map PremiumCheck!route-map PremiumCheck permit 10match community 17set ip precedence flash!route-map PremiumCheck permit 20set ip precedence 0!ip community-list 17 permit 12:17


Configure CEF Packet MarkingConfigure CEF Packet Marking

AS 12

WAN Core



ip cef switch!interface hssi 0/0bgp-policy destination ip-prec-mapip route-cache cef


IP QoS and BGP InteractionReview

IP QoS and BGP InteractionReview

• IP QoS features work independently of BGP routing

• BGP is used only to propagate policies for source or destination IP prefixes through the network


SummarySummary


• Describe the Cisco Express Forwarding (CEF) switching mechanism

• Describe the QoS packet classification and marking with CEF

• Describe the role of BGP in CEF-based QoS marking

• Configure QoS Policy Propagation with BGP (QPPB)

• Monitor and troubleshoot QPPB

• Deploy QPPB in large-scale BGP-based networks



• What is a FIB table?

• How is BGP information translated into QoS information in the FIB table?

• Describe the configuration steps for QPPB

• How many CEF lookups are performed for each packet when QPPB is enabled?

Overview of Web Caching in Large Networks

Overview of Web Caching in Large Networks





• Describe Web Caching components

• Describe the need for differentiated Web Caching behavior

• Identify the challenges of deploying differentiated Web Caching behavior in large-scale networks


What is Web Caching?What is Web Caching?

• Web Caching is a technology used primarily to intercepts HTTP requests and serve them locally

• A web cache stores the information for further requests for the same content

• Web Cache Communication Protocol (WCCP) is a protocol used between a router and a web cache


W W WW W W

Web Caching ExampleWeb Caching Example

• Access to non-cached web page

WebServer

Web Cache

http://acme.com

Redirect

www.acme.comwww.acm

e.com

http://acme.com


W W WW W W

Web Caching Example (cont.)Web Caching Example (cont.)

• Access to cached web page

WebServer

Web Cache

Redirect

www.acme.com

http://acme.com

The web cache device only needs to validate the web page


ServiceProvider

ServiceProvider

Why Web Caching?Why Web Caching?

• Among a large number of HTTP requests, many target a small number of most visited web pages

• Using a web cache can improve throughput and response times

• Estimate: 70% is web traffic and 50% of it is duplicate

ISP2ISP2

Not enough bandwidth to accomodate all requests

Poor response times because of congestion and distance


Web Cache Design OptionsWeb Cache Design Options

• What to cache:• which sources or destinations should be serviced by a

caching device;

• which applications should be serviced by a caching device - WCCP version 2 supports port numbers other than 80

• Where to cache (at ingress, egress or both)

• Do we need to provide differentiated quality of service for web traffic originating from customers using different classes of service


CustomerCustomer

Where to cacheWhere to cache

• Caching should be implemented as close to the source (customer or web server farm) as possible

• Caching devices may be located further away form the source (i.e. due to cost involved with a large number of caching devices)

ServiceProvider

ServiceProvider

ISP2ISP2

WWWW WW

WWWW WW

WWWW WW

Customers may use their own caching devices or proxies

A service provider may deploy a large number of caching devices on ingress points (POPs)

A service provider may deploy a small number of caching devices on egress points (close to NAPs)

WWWW WWWWWW WW

WWWW WW

A service provider may deploy caching in front of its web server farm to offload static content to caching devices

WWWW WW

WWWW WW


Differentiated Web CachingDifferentiated Web Caching

• WCCP design options:• Caching for all users

• Caching for some users (requires an access list)

• Grouping users into caching clusters (requires multiple access lists)

• The first option is simple to configure

• The other two require access lists to identify users. It is difficult to maintain accurate access lists and is, therefore, not scalable


SummarySummary


• Describe Web Caching components

• Explain the need for differentiated Web Caching behavior

• Identify the challenges of deploying differentiated Web Caching behavior in large-scale networks



• What is the purpose of web caching?

• How can web caching affect other QoS features implemented in a network?

• What is WCCP?

• What are the problems of setting up standard web caching?

WCCP Policy RedirectionWCCP Policy Redirection





• Describe the differentiated Web Caching mechanism controlled by the BGP table

• Configure WCCP Policy Redirection

• Monitor and troubleshoot WCCP Policy Redirection

• Deploy WCCP Policy Redirection in large-scale BGP-based networks


WCCP Policy RedirectionWCCP Policy Redirection

• BGP provides a scalable solution for classifying packets and Web Cache users

• There may be multiple classes of networks assigned to different web caching clusters

• Web cache clusters may have different services enabled

• Web cache clusters may have different QoS guarantees


Customer Driven WCCP Policy Redirection

Customer Driven WCCP Policy Redirection

• A decision whether to use a web cache can be left to a customer

• A customer can use BGP communities to choose the caching option

AS 12

WAN Core



10/8 12:1010/8 12:10

BGP community 12:10 is translated into internal WCCP tag 1

Customers network carries BGP community 12:10

WWWWWW


Provider Driven WCCP Policy Redirection

Provider Driven WCCP Policy Redirection

• A decision whether to use a web cache for a specific customer is determined by the ISP according to the SLA

• The service provider sets the appropriate BGP community attribute

AS 12

WAN Core



10/810/8 12:10

BGP community 12:10 is translated into internal WCCP tag 1

A service provider assigns a customer to a class according to an SLA

WWWWWW


Configuring WCCP Policy Propagation

Configuring WCCP Policy Propagation

Router(config-router)#

table-map name

Router(config)#

route-map name permit seq match ... set ip wccp policy-tag

• Apply a route map to updates going from the BGP table into the routing table

• Set the policy tag within a route map


Configuring WCCP Policy Propagation (cont.)


ip wccp version 2

Router(config)#

• WCCP policy redirection works if WCCP version 2 is used

ip wccp web-cache policy {source | destination} policy-tagor ip wccp service-tag policy {source | destination} policy-tag

Router(config)#

• Enables web caching for packets with source or destination matched in the FIB table if the packets have corresponding policy tags




ip wccp web-cache redirect {in | out}or ip wccp service-tag redirect {in | out}

Router(config-if)#

• Enables web caching on an interface


Monitoring WCCP Policy Redirection

Monitoring WCCP Policy Redirection

show ip cef [prefix] [detail]

router#

• Detailed CEF output shows WCCP tags

Router#show ip cef 10.1.1.0 detail10.1.1.0/24, version 35, cached adjacency to Serial0/0.10 packets, 0 bytes, wccp tag 1 via 10.3.0.2, 0 dependencies, recursive next hop 10.3.0.2, Serial0/0.1 via 10.3.0.0/30 valid cached adjacencyRouter#

Router#show ip cef 10.1.1.0 detail10.1.1.0/24, version 35, cached adjacency to Serial0/0.10 packets, 0 bytes, wccp tag 1 via 10.3.0.2, 0 dependencies, recursive next hop 10.3.0.2, Serial0/0.1 via 10.3.0.0/30 valid cached adjacencyRouter#


Monitoring WCCP Policy Redirection (cont.)

Monitoring WCCP Policy Redirection (cont.)

show ip interface [interface]

router#

• Shows whether WCCP is enabled on an interface

Router#show ip interfaceSerial0 is up, line protocol is up Internet address is 10.3.0.2/30 Broadcast address is 255.255.255.255 ... Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is enabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled …

Router#show ip interfaceSerial0 is up, line protocol is up Internet address is 10.3.0.2/30 Broadcast address is 255.255.255.255 ... Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is enabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled …


WCCP Policy Redirection Case Study

WCCP Policy Redirection Case Study

• A service provider has three types of users:

• Dial-up users

• Best-effort users

• Premium users

• Each group is assigned to a separate cluster of web cache devices

• A Premium customer is allowed to disable web caching


Case Study - DesignCase Study - Design

• The service provider uses four digits in BGP communities

• The third digit is used for web caching options

Service BGP Community

Dial-up Users 387:1x0x

Best Effort Users 387:1x1x

Premium Users 387:1x2x

No Caching 387:1x3x


Case Study – Network LayoutCase Study – Network Layout

AS 387 AS 387

PremiumCustomer

PremiumCustomer

ISP2ISP2

Best-effort

Customer

Best-effort

Customer

PSTN / ISDN

PSTN / ISDN

W W WW W WW W WW W WW W WW W W

Dial-up pools are inserted into BGP and marked with 387:1000

Premium customer is marked with 387:1020 if not already marked with 387:1030

Best-effort customer is marked with 387:1010

WCCP Policy Redirection based on BGP communities


Case Study – Dial-up UsersCase Study – Dial-up Users

AS 387 AS 387

PremiumCustomer

PremiumCustomer

ISP2ISP2

Best-effort

Customer

Best-effort

Customer

PSTN / ISDN

PSTN / ISDN


ip local pool DIALUP 192.168.10.1 192.168.10.254ip route 192.168.10.0 255.255.255.0 null 0!router bgp 387 network 192.168.10.0 route-map SetCommunity!route-map SetCommunity permit 10 set community 387:1000!


Case Study – Best-effort UsersCase Study – Best-effort Users

AS 387 AS 387

PremiumCustomer

PremiumCustomer

ISP2ISP2

Best-effort

Customer

Best-effort

Customer

PSTN / ISDN

PSTN / ISDN


ip route 200.200.200.0 255.255.255.0 serial 0 tag 1010!router bgp 387 redistribute static route-map BestEffort!route-map BestEffort permit 10 match tag 1010 set community 387:1010 set origin igp!


Case Study – Premium UsersCase Study – Premium Users

AS 387 AS 387

PremiumCustomer

PremiumCustomer

ISP2ISP2

Best-effort

Customer

Best-effort

Customer

PSTN / ISDN

PSTN / ISDN


! Static Premium Customerip route 150.1.1.0 255.255.255.0 serial 0 tag 1020!router bgp 387 redistribute static route-map Premium neighbor 192.168.1.2 remote-as 65001 neighbor 192.168.1.2 description BGP Premium neighbor 192.168.1.2 route-map Premium in!

route-map StaticPremium permit 10 match tag 1020 set community 387:1020 set origin igp!route-map BGPPremium permit 10 match community 120!route-map BGPPremium permit 20 set community 387:1020!ip community-list 120 permit _387:..3._


Case Study – Policy Redirection

Case Study – Policy Redirection

AS 387 AS 387

PremiumCustomer

PremiumCustomer

ISP2ISP2

Best-effort

Customer

Best-effort

Customer

PSTN / ISDN

PSTN / ISDN


router bgp 387 table-map WCCP_PP!route-map WCCP_PP permit 10 match community 100 set ip wccp 1!route-map WCCP_PP permit 20 match community 101 set ip wccp 2!route-map WCCP_PP permit 30 match community 102 set ip wccp 3!route-map WCCP_PP permit 1000!ip community-list 100 permit _387:..0._ip community-list 101 permit _387:..1._ip community-list 102 permit _387:..2._

ip cef!ip wccp version 2ip wccp 1 policy source 1ip wccp 2 policy source 2ip wccp 3 policy source 3!interface hssi1/0 ip wccp 1 redirect out ip wccp 2 redirect out ip wccp 3 redirect out!


SummarySummary


• Describe the differentiated Web Caching mechanism controlled by the BGP table

• Configure WCCP Policy Redirection

• Monitor and troubleshoot WCCP Policy Redirection

• Deploy WCCP Policy Redirection in large-scale BGP-based networks



• What is the purpose of using BGP for WCCP policy propagation?

• What is a WCCP tag?

• What is the relation between BGP attributes and WCCP tags?

• List the configuration steps to enable WCCP based on BGP attributes.


SummarySummary

After completing this chapter, you should be able to perform the following tasks:

• Describe the basics of the Differentiated Services QoS model

• Identify the issues of deploying DiffServ QoS model in large-scale networks

• Configure and monitor QoS Policy Propagation via BGP (QPPB)

• Describe the basics of Web Caching

• Identify the issues of deploying differentiated Web Caching in large-scale networks

• Configure and monitor Web Caching Communication Protocol (WCCP) Policy Redirection


Documents

© 2001, Cisco Systems, Inc. Policy Propagation Through BGP