Cisco Wide Area Application Engine 612 Manual de usuario descargar pdf (Pagina 14)

88 Chapter 4: Network Integration and Interception

Well-known services, also referred to as static services, have a ﬁxed set of characteristics

that are known by both IOS and WCCPv2 client devices. There is currently a single well-

known service called web-cache. This service redirects all TCP trafﬁc with a destination

port of 80. The characteristics of a dynamic service are initially only known to the WCCPv2

clients within the service group. The characteristics of the service group are communicated

to the IOS devices by the ﬁrst WCCPv2 client device to join the service group.

A unique service ID identiﬁes service groups, which is a number from 0 to 255. Service IDs

0 to 50 are reserved for well-known services.

The WCCPv2 implementation in WAAS supports a single dynamic WCCPv2 service,

the tcp-promiscuous service. Although referred to in WAAS as a single service, the tcp-

promiscuous service is in fact two different services. The two service IDs enabled with the

tcp-promiscuous service are 61 and 62. These are the two service group IDs that are con-

ﬁgured in IOS when using WCCPv2 with WAAS. Two different service groups are used

because both directions (client-to-server and server-to-client) of a TCP connection must be

transparently intercepted. To optimize a connection, WAAS must see both directions of the

connection on the same WAE. Not only does WAAS intercept the connection in both direc-

tions, but it also intercepts the connection on both sides of the WAN link. Because the packet

Layer 3 and Layer 4 headers are preserved, transparent interception is used on both sides

of the WAN in both directions to redirect connections to the WAAS infrastructure for

optimization. Figure 4-5 shows a basic topology with WCCPv2 interception conﬁgured

for WAAS.

Figure 4-5 Basic Network Topology with WCCP

What is the difference between services 61 and 62? You can view the service attributes

using CLI commands in both WAAS and IOS. Example 4-9 shows the attributes of services

61 and 62 using the IOS CLI.

WAN

WAE WAE

Intercepts client request.

Intercepts server response.

1 2 ... 9 10 11 12 13 14 15 16 17 18 19 ... 40 41

Sin comentarios

Cisco Wide Area Application Engine 612 Manual de usuario Pagina 14