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Configuring the Cisco Cache Software

Configuring the Cisco Cache Software

This chapter describes the Cisco Content Engine and considerations for configuring the Cache software.

Content Engine Overview

Cisco Content Engines with Cache software are elements of a larger Cisco Content Delivery Network (CDN) solution, which includes content routing, content switching, content delivery network management, and content services, as well as content distribution and delivery.

Cisco Content Engines are installed strategically within your existing network to provide accelerated content delivery to the desktop user. Cisco Content Engines with Cache software accelerate content delivery and optimize bandwidth usage by transparently caching frequently accessed content and fulfilling content requests locally rather than traversing the Internet or intranet to a distant server each time a request is made. For transparent processing of Web traffic, the Content Engine works with a router or a Layer 4 (L4)-enabled switch.

To implement transparent caching with routers, your network must implement Cisco IOS software and the Web Cache Communication Protocol (WCCP). (WCCP is also known as Web Cache Control Protocol and Web Cache Coordination Protocol.) WCCP redirects Hypertext Transfer Protocol (HTTP) traffic to a Content Engine; the Content Engine then manages the Web request.

When a user requests an object from a Web server, the router first sends the request to a Content Engine. If the Content Engine has a copy of the requested object in storage, the Content Engine sends the user the object. Otherwise, the Content Engine gets the requested objects from the Web server, stores a copy of the objects (caches them), and simultaneously forwards the objects on to the user.

By caching Web objects in this manner, the Content Engine can speed the fulfillment of user requests if more than one user wants to access the same objects. This also reduces the amount of traffic between your network and the Internet, potentially improving your overall network performance and optimizing your bandwidth usage.

The Content Engine is configured with the command-line interface (CLI) or the Web-based management interface, which is a graphical user interface (GUI) accessed with a Web browser. Most configuration options can be made with the management interface, which also provides online help pages.

Performing an Initial Startup Configuration

After you physically install the hardware, you must perform an initial software configuration by completing the following tasks:

    1. Collecting the Information Required for Initial Configuration

    2. Initializing the Cache Software

    3. Enabling and Disabling Cache Support on the Router

    4. Verifying the Software Configuration

    5. Logging On to the Management Interface

Collecting the Information Required for Initial Configuration

Have the following information available. When you power on the Content Engine for the first time, you will be prompted to provide this information:

Initializing the Cache Software

To perform and initial configuration after the operating system has booted, complete the following steps:

Step 1   Open a terminal emulation session on the host connected to the console port, and power on the Content Engine.

When the Content Engine begins booting, the following prompt appears:

Would you like to enter the initial configuration? [yes]:

Step 2   Enter yes, and then enter values for the following fields as you are prompted:

This is the password you want to use for the admin administrator user account. The password is case sensitive and can be up to 20 characters, including spaces and any printable characters. You must enter a password for each Content Engine. You cannot set the passwords globally.

    Note   The Cache software does not display ***** (asterisks) while you are verifying your admin password.
Other interfaces can be configured later with the CLI.
A netmask specifies which part of the IP address refers to the network; you can accept the default value by pressing Enter, or enter a different value.

This is the IP address of the router that allows the Content Engine to connect to the network. It is not necessarily the same as the IP address of the Content Engine's home router or routers.

After you enter the initial configuration data, the following prompt appears:

Use this configuration? [yes]:

Step 3   If the initial configuration is acceptable, enter yes or press Enter.

The Content Engine performs hardware and software initialization tasks and then serves a login challenge that, when answered correctly, launches the CLI. At this point, the initial configuration is complete.

Would you like to enter the initial configuration? [yes]:yes host name:7320-1 domain name:cisco.com admin password:albatros Please enter an interface from the following list: 0:GigabitEthernet 1/0 1:GigabitEthernet 2/0 2:FastEthernet 3/0 3:FastEthernet 3/1 4:FastEthernet 3/2 5:FastEthernet 3/3 enter choice:2 cache IP address: 10.1.58.5 IP network mask:255.255.255.0 gateway IP address:10.1.58.1 DNS server:172.16.2.132 Use this configuration? [yes]:yes INIT:Entering runlevel:3 Entering non-interactive startup . . . Cisco Content Engine Console Username:Verifer ver_wserver registered for ex/gl/debug/wi usermod[57]:change user \Qadmin' password /dev/raw/raw102: bound to major 8, minor 33 /dev/raw/raw103: bound to major 8, minor 49 /dev/raw/raw104: bound to major 8, minor 65 /dev/raw/raw105: bound to major 8, minor 81 /dev/raw/raw106: bound to major 8, minor 97 /dev/raw/raw107: bound to major 8, minor 113 /dev/raw/raw108: bound to major 8, minor 129 /dev/raw/raw109: bound to major 8, minor 145 disk10 is missing. Host:4, Channel:0, Scsi ID:0 disk11 is missing. Host:4, Channel:0, Scsi ID:1 disk12 is missing. Host:4, Channel:0, Scsi ID:2 disk13 is missing. Host:4, Channel:0, Scsi ID:3 disk14 is missing. Host:4, Channel:0, Scsi ID:4 disk15 is missing. Host:4, Channel:0, Scsi ID:5 disk16 is missing. Host:4, Channel:0, Scsi ID:8 disk17 is missing. Host:4, Channel:0, Scsi ID:9 disk18 is missing. Host:4, Channel:0, Scsi ID:10 disk19 is missing. Host:4, Channel:0, Scsi ID:11 disk20 is missing. Host:4, Channel:0, Scsi ID:12 disk21 is missing. Host:4, Channel:0, Scsi ID:13 disk00 (scsi host 0, channel 0, id 0) FS: sysfs mounted at: /local1 disk01 (scsi host 0, channel 0, id 1) FS: sysfs mounted at: /local2 disk02 (scsi host 3, channel 0, id 0) FS: cfs mounted disk03 (scsi host 3, channel 0, id 1) FS: cfs mounted disk04 (scsi host 3, channel 0, id 2) FS: cfs mounted disk05 (scsi host 3, channel 0, id 3) FS: cfs mounted disk06 (scsi host 3, channel 0, id 4) FS: cfs mounted disk07 (scsi host 3, channel 0, id 5) FS: cfs mounted disk08 (scsi host 3, channel 0, id 8) FS: cfs mounted disk09 (scsi host 3, channel 0, id 9) FS: cfs mounted disk10 (scsi host 4, channel 0, id 0) NOT available disk11 (scsi host 4, channel 0, id 1) NOT available disk12 (scsi host 4, channel 0, id 2) NOT available disk13 (scsi host 4, channel 0, id 3) NOT available disk14 (scsi host 4, channel 0, id 4) NOT available disk15 (scsi host 4, channel 0, id 5) NOT available disk16 (scsi host 4, channel 0, id 8) NOT available disk17 (scsi host 4, channel 0, id 9) NOT available disk18 (scsi host 4, channel 0, id 10) NOT available disk19 (scsi host 4, channel 0, id 11) NOT available disk20 (scsi host 4, channel 0, id 12) NOT available disk21 (scsi host 4, channel 0, id 13) NOT available Checking SYSFS on disk00 SYSFS disk00 has been checked OK Mounted disk00 to /local1 Checking SYSFS on disk01 SYSFS disk01 has been checked OK Mounted disk01 to /local2 Disk configuration is initialized [Display output omitted.] Cisco Content Engine Console Username: admin Password: 7320-1 con now available Press RETURN to get started! 7320-1>enable 7320-1#

Enabling and Disabling Cache Support on the Router

Although the Content Engine with Cache software can function as a standalone proxy server and Web cache, it is often used with a router running the Web Cache Communication Protocol (WCCP) to provide transparent proxy and caching services. When cache support is enabled on the router, and WCCP support enabled on the Content Engines, the devices can communicate and deliver the services for which they are configured. You can disable cache support on the router to suspend proxy and caching services, rather than turning off or otherwise disabling individual Content Engines. (Use the no ip wccp command on the router to disable caching.)

You must already know how to configure the router to make these configuration changes. If you do not know how to configure the router, refer to the Cisco IOS documentation supplied with the router. Detailed information for the commands mentioned here is in the Cisco IOS documentation. See "Web Cache Communication Protocol Version 1," and "Web Cache Communication Protocol Version 2," for information on which Cisco IOS software release supports which version of WCCP on which platform.

Disabling Transparent Caching Services on the Content Engine

To remove a Content Engine from a Content Engine cluster or from a WCCP environment without powering it down, disable the running version of WCCP on the Content Engine by issuing the Cache software no wccp version 1 (or 2) command. The Content Engine will still service proxy-style requests and preserve its configuration settings.

Cache Support on the Router for WCCP Version 1

Step 1   Ensure that the router is running a release of the Cisco IOS software that includes WCCP Version 1. If it does not have this support, you must upgrade the Cisco IOS software before you can continue.

Step 2   In global configuration mode, use the ip wccp enable command to enable cache support. For example, enter:

router(config)# ip wccp enable

Step 3   In interface configuration mode, use the ip web-cache redirect command to have the interface redirect packets on port 80 to the Content Engine. Enter this command for each interface that is an outgoing interface connecting to the following:

For example, to enable redirection, enter:

router(config-if)# ip web-cache redirect

You can confirm your settings using the following show commands on the router:

Cache Support on the Router for WCCP Version 2

Many WCCP Version 2 features also require a configuration of the Cache software wccp global configuration command. Refer to the command reference and release notes for the Cache software release you are using for more details. For instance, WCCP services 90-97 are not supported in Release 3.0.0 of the Cache software.

Note   This chapter may include descriptions of WCCP Version 2 features that may not be supported in your release of the Cisco Cache software. Refer to the release notes for your version of the Cache software for further information.
Step 1   Ensure that the router is running a release of the Cisco IOS software that includes WCCP Version 2. If it does not have this support, you must upgrade the Cisco IOS software before you can continue.

In global configuration mode, use the ip wccp command to enable cache support. For example, enter:

router(config)# ip wccp webcache

or

router(config)# ip wccp service-number

where service-number is the number of a predefined service (0 to 99).

Step 2   In interface configuration mode, use the ip wccp web-cache redirect out or ip wccp service-number redirect out command to have the interface redirect packets to the Content Engine. Enter this command for each interface that is an outgoing interface connecting to the following:

For example, to enable redirection on port 80, enter:

router(config-if): ip web-cache redirect out

To enable redirection of HTTP traffic on port 80 and on another port, enter:

router(config-if): ip wccp 98 redirect out

You can confirm your settings using the following show commands on the router:

Verifying the Software Configuration

Once you have installed and configured the Content Engine and enabled caching on the router, check that the Cache software is working properly.

Step 1   From a machine on a network that uses the home router or routers, start a Web browser and open various Web pages on the Internet or your intranet. The Web servers you connect to must be on a different subnet, so that the request goes through the home router or routers. Connect to some pages more than once, to ensure that some pages you request are in the cache.

Step 2   From the CLI, enter the following to display the Content Engine HTTP caching saving statistics:

show statistics http savings

Step 3   Open a window for the Content Engine console using your terminal emulation program to connect to the home router or routers, and enter the show ip wccp web-cache command to display information about the Content Engine.

The entry for the Content Engine should show a number greater than 0 for packets redirected. Also, check for hash assignments.

If the router shows that no packets are being redirected to the Content Engine, you must troubleshoot your setup.

Logging On to the Management Interface

You can manage the Content Engine with the CLI or the Content Engine management interface. To connect to the Content Engine management interface, perform the following steps.

Note   Be sure to enable Java, JavaScript, and Cascading Style Sheets on your Internet Explorer browser, or use the Netscape 4.0 or later browser.
Step 1   Start a Web browser on a machine that has access to the network on which the Content Engine resides.

Step 2   Open the URL with the cache IP address specified in the initial Content Engine configuration. Append the default port number 8001. For example:

http://10.1.58.5:8001

You are prompted for a username and password. (See Figure 1-1.)


Figure 1-1: Administrator's Login


Step 3   Enter a correct username and password. The Content Engine returns the initial management page, which contains links to other management pages.

If you forget your password, you must have another administrator reset your password. The password for the user admin is specified in the initial system configuration dialog.

Removing or Replacing a Content Engine

Refer to the Content Engine hardware documentation for instructions on physically removing a Content Engine from an active network.

The router and the Content Engine are in constant communication; thus, when the router notices that the engine is no longer responding to it, the router stops sending requests to the engine. This is transparent to users. If other Content Engines are attached to the router, the router continues sending requests to the other engines.

When you remove a Content Engine, the pages that were cached on the engine are no longer available to the router or other Content Engines. Thus, you might see an increase in outgoing Web traffic that might have otherwise been fulfilled by the engine you are removing. However, after a time, the router and other Content Engines will have redistributed the load of Web traffic.

If you remove the last Content Engine from a router, you can also disable cache support on the router. However, this is not necessary; having cache support enabled when there are no Content Engines attached has no effect on the router's performance.

To replace a Content Engine, remove the old engine from the network. Then, add the new engine and configure it using the same configuration parameters (IP address, and so forth) that you used for the removed engine.


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Posted: Wed Jun 6 14:47:44 PDT 2001
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