Cabletron Systems SSIM-R8-02 Specifikace stáhnout pdf (Strana 312)

Using ACLs

292 Enterasys Xpedition User Reference Manual

Using Profile ACLs with the Web Caching Facility

Web caching is the XP’s ability to direct HTTP requests for frequently accessed Web

objects to local cache servers, rather than to the Internet. Since the HTTP requests are

handled locally, response time is faster than if the Web objects were retrieved from the

Internet.

You can use Profile ACLs with Web caching in two ways:

• Specifying which HTTP traffic should always (or never) be redirected to the cache

servers

• Specifying characteristics of Web objects that should not be cached

Redirecting HTTP Traffic to Cache Servers

You can use a Profile ACL to specify which HTTP traffic should always (or never) be

redirected to the cache servers. (By default, when Web caching is enabled, all HTTP traffic

from all hosts is redirected to the cache servers unless you specify otherwise.)

For example, you can specify that packets with a source address of 10.10.10.10 and a

destination address of 1.2.3.4 always are sent to the Internet and never to the cache

servers. The following commands illustrate this example.

This command creates a Profile ACL called prof4 that uses as its selection criteria all

packets with a source address of 10.10.10.10 and a destination address of 1.2.3.4:

The following command creates a Web caching policy that prevents packets matching

Profile ACL prof4’s selection criteria (that is, packets with a source address of 10.10.10.10

and a destination address of 1.2.3.4) from being redirected to a cache server. Packets that

match the profile’s selection criteria are sent to the Internet instead.

When the Web caching policy is applied to an interface (with the web-cache apply

interface command), HTTP traffic with a source address of 10.10.10.10 and a destination

address of 1.2.3.4 goes to the Internet instead of to the cache servers.

Preventing Web Objects From Being Cached

You can also use a Profile ACL to prevent certain Web objects from being cached. For

example, you can specify that information in packets originating from Internet site 1.2.3.4

and destined for local host 10.10.10.10 not be sent to the cache servers. The following

commands illustrate this example.

ssr(config)# acl prof4 permit ip 10.10.10.10 1.2.3.4

ssr(config)# web-cache policy1 deny hosts profile prof4

1 2 ... 307 308 309 310 311 312 313 314 315 316 317 ... 393 394

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Cabletron Systems SSIM-R8-02 Specifikace Strana 312