User manual

Cache setup

Cobalt CacheRaQ 4 User Manual 39

Web Cache Communication Protocol v1 (WCCP)

To access the WCCP Settings, click WCCP at the top. The WCCP Settings table

appears.

WCCP allows the CacheRaQ 4 to communicate with a WCCP-enabled router

(usually a piece of equipment from Cisco Systems®) and to be integrated into a

WCCP-enabled network.

With WCCP v1, a single router services a cluster; this router is the device that

redirects all IP packets.

The following sequence of events details how WCCP v1 conﬁguration works:

1. Each cache server is conﬁgured by the system administrator with the

IP address of the control router. Up to 32 cache servers can connect to a

single control router.

2. A cache server transmits its IP address to the control router using WCCP,

indicating its presence. Routers and cache servers communicate to each

other through a control channel; this channel is based on UDP port 2048.

3. This information is used by the control router to create a cluster view (a list

of caches in the cluster). This view is transmitted to each cache in the cluster,

essentially making all the cache servers aware of each other. A stable view is

established after the membership of the cluster remains the same for a

certain amount of time.

4. Once a stable view has been established, one cache server is elected as the

lead cache server. The lead is deﬁned as the cache server with the lowest

IP address that is seen by all the cache servers in the cluster. This lead cache

engine uses WCCP to indicate to the control router how to redirect the

IP packets. Speciﬁcally, the lead cache engine designates how redirected

trafﬁc should be distributed across the cache servers in the cluster.

To conﬁgure the WCCP-enabled router, refer to the manufacturer’s

documentation.

In the WCCP Router ﬁeld, enter the fully qualiﬁed host name or the IP address of

the WCCP v1 router.

If you make any changes, click Save Changes before leaving this screen.

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Note: The CacheRaQ 4 only supports version 1 (v1) of the Web

Cache Communication Protocol.