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CSS Basic Configuration Guide (Software Version 5.00)
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Content Services Switch Basic Configuration Guide Index (Software Version 5.00)
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About This Guide
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Logging in and Getting Started
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Configuring User Profiles and CSS Parameters
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Configuring CSS Network Protocols
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Configuring Interfaces and Circuits
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Configuring Services
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Configuring Owners
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Configuring Content Rules
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Using the CSS Logging Features
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Configuring Simple Network Management Protocol (SNMP)
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Configuring Remote Monitoring (RMON)
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Upgrading Your CSS Software
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Table Of Contents
Service, Owner, and Content Rule Overview
Service Configuration Quick Start
Using ArrowPoint Content Awareness Based on Server Load and Weight
Using ACA Based on Server Load
Using ACA Based on Server Weight and Load
Configuring Global Load Threshold
Configuring Global Load Reporting
Configuring Load Tear Down Timer
Activating a Global Keepalive Active
Configuring a Global Keepalive Description
Configuring a Global Keepalive Frequency
Configuring a Global Keepalive IP Address
Configuring a Global Keepalive Max Failure
Configuring a Global Keepalive Method
Configuring a Global Keepalive Port
Configuring a Global Keepalive Retryperiod
Deactivating a Global Keepalive
Configuring a Global Keepalive Type
Configuring a Global Keepalive URI
Associating a Service with a Global Keepalive
Configuring Global Keepalive Hash
Showing Global Keepalive Configurations
Script Keepalive Considerations
Viewing a Script Keepalive in a Service
Script Keepalives and Upgrading WebNS Software
Assigning an IP Address to the Service
Configuring an Advanced Load Balancing String
Configuring a Service HTTP Cookie
How the CSS Accesses Server Types
Configuring Service Cache Bypass
Configuring Network Address Translation for Transparent Caches
Configuring a Service to Bypass a Cache Farm
Configuring Keepalives for a Service
Configuring Keepalive Frequency
Configuring Keepalive Maxfailure
Configuring Keepalive Retryperiod
Showing Keepalive Configurations
Configuring Maximum TCP Connections
Removing a Service From a Content Rule
Removing a Service From a Source Group
Showing Service Configurations
Configuring Services
This chapter describes how to configure services. This chapter also contains an overview on the association between services, owners, and content rules. Information in this chapter applies to all CSS models except where noted.
This chapter contains the following sections:
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Service, Owner, and Content Rule Overview
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Service, Owner, and Content Rule Overview
The CSS enables you to configure services, owners, and content rules to direct requests for content to a specific destination service (for example, a server or a port on a server). By configuring services, owners, and content rules, you optimize and control how the CSS handles each request for specific content.
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(a local or remote server and port). You add services to content rules. Adding a service to a content rule includes it in the resource pool that the CSS uses for load-balancing requests for content. A service may belong to multiple content rules.•
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The CSS uses content rules to determine:
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When a request for content is made, the CSS:
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illustrates the CSS service, owner, and content rule concepts.
Figure 5-1 Services, Owners, and Content Rules Concepts
Service Configuration Quick Start
Table 5-1 provides a quick overview of the steps required to configure services. Each step includes the CLI command required to complete the task. For a complete description of each feature and all the options associated with the CLI commands, refer to the sections following Table 5-1.
Service Load Overview
Server load is a mechanism to express the current load experienced by a server. The CSS calculates load by using the variances in normalized response times from client to server to determine a server's load number. A server with a heavier processing load would be biased toward a more significant, larger, load number.
To configure global load parameters for the eligibility and ineligibility of CSS services, use the load report, load teardown timer, and load ageout timer commands (discussed later in this section).
You can adjust load calculations by changing the load step size, which is the difference in milliseconds between load numbers. The CSS can determine the load step dynamically, or you can configure the initial load step using the global load step command.
The load on a service has a range of 2 to 255, with an eligible load of 2 to 254. An eligible service is an active service that can receive flows. A service with a load of 255 is offline.
A service becomes ineligible to receive flows when its load number exceeds the configured load threshold. The CSS uses the configured ageout timer value to return the service to the eligible state.
For the CSS to consider the server loads as different, response times of the servers must differ by the configured load step or greater. If the response times differ by less than the configured load step, the CSS considers the servers to have the same load.
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shows servers A, B, and C with response times of 100 ms, 1100 ms, and 120 ms, respectively. One group of servers has load step configured to 10 ms. The second group of servers has load step configured to 100 ms.
Figure 5-2 Load Calculation Example with Three Servers
For the servers set to the 10 ms load step, the difference in response time between:
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For the servers set to 100 ms load step, the difference in response time between:
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Increasing the load step causes the load for servers to be closer to each other. Decreasing the load step causes the load for servers to be further from each other.
To enable you to configure an accurate load threshold for a server, you can calculate a load number for a server. To calculate a server load number:
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For example, to calculate the load number for serverC with the 10 ms load step:
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Using ArrowPoint Content Awareness Based on Server Load and Weight
ArrowPoint Content Awareness (ACA) load-balancing algorithm balances traffic between a group of servers. You can configure the CSS to make ACA load-balancing decisions based on:
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Using ACA Based on Server Load
ACA determines the best service for each content request based on server load and size of the content being requested. ACA estimates the file size based on previous requests for the same content. A service with a lower load receives more flows than a service with a higher load.
Using ACA Based on Server Weight and Load
Server weight is a mechanism to express the processing capabilities of a server. Weights allow you to configure the CSS to prefer one group of servers over another. When you configure weights, the number of hits per server is relative to the weight configured on that server. A higher weight will bias flows toward the specified server. For example, in Figure 5-2, ServerA with a weight of two is hit twice as much as ServerB that has a weight of one. ServerC has a weight of 10 and is hit 10 times as much as ServerB. All servers with the same weight are hit equally in a roundrobin manner.
The CSS can use a server's weight in tandem with server load to determine server availability. When you configure ACA on a content rule to use both weight and load, the CSS calculates the number of requests per weight level based on the number of servers with that weight. The CSS then balances the requests among the servers based on their individual loads. The number of requests per weight level is equal to weight level * number of servers *10. The CSS then increments the weight level, and uses the same mechanism to balance requests among the servers in the next weight level.
For information on configuring weight for a service, refer to the section "Configuring Weight" described later in this chapter. Also see the section "Specifying a Service Weight" in <Xref_Color>Chapter 7, Configuring Content Rules.
Configuring Load for Services
The options for the global load command are:
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For more information on these options and associated variables, refer to the following sections.
Configuring Global Load Step
Use the load step command to set the global load step, which is the difference in milliseconds between load numbers. Load numbers have a range from 2 to 254. By default, the CSS starts at a load step of 10 ms and then dynamically calculates the load step as it accumulates minimum and maximum response times for the services.
When you configure the load step to reduce the flows to a slower service, consider the differences in response times between services. For example:
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The options and syntax for this global configuration mode command are:
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Enter the load step in milliseconds from 10 to 1000000000. The default is 10 ms. For example, to set the load step to 100 ms, enter:
(config)# load step 100To set the load step to the default of 10 ms, enter:
(config)# no load stepConfiguring Global Load Threshold
Use the load threshold command to define the global load number which the CSS uses to determine if a service is eligible to receive flows. If the service load exceeds the threshold, the service becomes ineligible to receive flows until the CSS ages the service into the eligible state.
Enter the threshold as a number from 2 to 254. The default is 254, which is the maximum threshold services can reach before becoming unavailable. To view the global load on services, enter show load (see Table 5-2 for details).
For example, to set the load threshold to 25, enter:
(config)# load threshold 25
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To set the load threshold to the default of 254, enter:
(config)# no load thresholdConfiguring Global Load Reporting
Use the load reporting command to enable the CSS to generate teardown reports and derive load numbers. A teardown report is a summary of response times for services when flows are being torn down. The CSS uses the teardown report to derive the load number for a service. The default is load reporting enable.
If you are not concerned about load reporting, disable it and it may increase performance (depending on flows and load reporting already occurring). To disable load reporting, enter:
(config)# no load reportingTo reenable load reporting, enter:
(config)# load reportingConfiguring Load Tear Down Timer
Use the load teardown-timer command to set the maximum time between teardown reports. A teardown report is a summary of response times for services when flows are being torn down. The CSS uses the teardown report to derive the load number for a service.
When the SFM has sufficient teardown activity for a service, it generates a teardown report and the teardown timer is reset. If a teardown report is not triggered at the end of the teardown timer interval due to insufficient activity, the CSS triggers the SFM to generate a teardown report based on its current activity. If there is no activity on the SFM, no report is generated and the timer resets.
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Enter the teardown timer as the number of seconds between teardown reports. enter an integer from 0 to 1000000000. The default is 20. The value of 0 disables the timer. For example, to set the teardown timer to 120 seconds, enter:
(config)# load teardown-timer 120To reset the teardown time interval to its default of 20 seconds, enter:
(config)# no load teardown-timerConfiguring Load Ageout Timer
Use the load ageout-timer command to set the time interval in seconds in which the CSS ages out stale load information for a service. When the ageout timer interval expires, the CSS erases the information and resets the service load to 2. Load information is stale when the teardown report number recorded on a service has not incremented during the ageout time interval because no flows (long or short) are being torn down on the service.
At the beginning of the time interval, the ageout timer saves the number of the current teardown report. When the SFM generates a a new teardown report, the report number in the SFM increments and any services in the report saves this number. At the end of the ageout time interval, the CSS compares the initial teardown number, saved at the beginning of the time interval, with the current teardown number saved by each service. If the number of a service is less than or equal to the timer number, the load information is stale. The CSS erases it and the service load is reset to 2.
Enter the ageout timer as the number of seconds to age out load information for a service. Enter an integer from 0 to 1000000000. The default is 60. The value of
0 disables the timer.For example:
(config)# load ageout-timer 180To set the ageout time to the default of 60, enter:
(config)# no load ageout-timerShowing Global Service Loads
Use the show load command to display the global load configuration and service load information. For example:
(config)# show loadTable 5-2 describes the fields in the show load output.
Global Keepalive Mode
Global keepalive configuration mode allows you to create a global keepalive and configure its properties. Once you create and configure a keepalive, you can apply it to any service. Applying a keepalive to multiple services reduces the amount of configuration required for each service.
Global keepalives are independent of service mode. In service mode, you can also configure individual keepalive properties for a service. Global keepalives supersede the individual keepalive parameters configured in service mode.
The CSS supports a maximum of 512 keepalives (which can include a maximum of 255 script keepalives). The CSS supports a maximum of 256 keepalives of one type. These keepalives include:
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To access keepalive configuration mode, use the keepalive command from circuit, global, interface, and IP configuration modes. The prompt changes to (config-keepalive [name]). You can also use this command from keepalive mode to access another keepalive.
The following sections describe how to configure global keepalives:
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Creating a Global Keepalive
Use the keepalive command to access keepalive configuration mode and configure global keepalive properties which you can apply to any service. Enter the name of the new keepalive you want to create or the name of an existing keepalive. Enter an unquoted text string with no spaces and a length of 1 to 31 characters. To see a list of existing keepalive names, enter keepalive ?.
The following example creates global keepalive keepimages.
(config)# keepalive keepimagesWhen you access this mode, the prompt changes to (config-keepalive [keepimages]).
(config-keepalive[keepimages])#To remove an existing keepalive, enter:
(config)# no keepalive keepimagesActivating a Global Keepalive Active
Use the active command to activate the global keepalive. Activating a keepalive enables the CSS to start sending keepalive messages to the IP address.
For example, to activate the global keepalive keepimages, enter:
(config-keepalive[keepimages])# activeConfiguring a Global Keepalive Description
Use the description command to specify the description for a keepalive. Enter the description as a quoted text string with a maximum of 64 characters, including spaces.
For example, to enter a description for the global keepalive keepimages, enter:
(config-keepalive[keepimages])# description "This keepalive is for the image servers"To delete a description, enter:
(config-keepalive[keepimages])# no descriptionConfiguring a Global Keepalive Frequency
Use the frequency command to specify the time between sending keepalive messages to the IP address. Enter the frequency time in seconds as an integer from
2 to 255. The default is 5.
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For example, to set the frequency time to 10 seconds, enter:
(config-keepalive[keepimages])# frequency 10To reset the frequency to its default value of 5, enter:
(config-keepalive[keepimages])# no frequencyConfiguring a Global Keepalive IP Address
Use the ip address command to specify the IP address where the keepalive messages are sent. Enter the IP address in dotted-decimal notation.
For example, to enter an IP address for keepalive keepimages, enter:
(config-keepalive[keepimages])# ip address 192.168.7.6Configuring a Global Keepalive Max Failure
Use the maxfailure command to specify the number of times the IP address can fail to respond to a keepalive message before the CSS considers it down. Enter the maximum failure as an integer from 1 to 10. The default is 3.
For example, to set the global keepalive maxfailure number to 7, enter:
(config-keepalive[keepimages])# maxfailure 7To reset the maximum failure number to its default value of 3, enter:
(config-keepalive[keepimages])# no maxfailureConfiguring a Global Keepalive Method
Use the method command to specify the HTTP keepalive method assigned to the global keepalive. The syntax and options for the keepalive mode command are:
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When you specify the content information of an HTTP Uniform Resource Identifier (URI) for an HTTP keepalive, the CSS calculates a hash value for the content. If the content information changes, the hash value no longer matches the original hash value and the CSS assumes that the service is down. To prevent the CSS from assuming that a service is down due to a hash value mismatch, specify the keepalive method as head.
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For example, to specify the HTTP get keepalive method, enter:
(config-keepalive[keepimages])# method getConfiguring a Global Keepalive Port
Use the port command to specify the port number used for global HTTP keepalives. Enter the port number associated with the global keepalive as an integer from 0 to 65535.
If configured, the CSS uses the TCP keepalive port. Otherwise, the CSS bases the default on the keepalive type. If the keepalive type is:
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For example, to set the global keepalive port to 8080, enter:
(config-keepalive[keepimages])# port 8080To reset the port to the default of 0, enter:
(config-keepalive[keepimages])# no portConfiguring a Global Keepalive Retryperiod
Use the retryperiod command to specify the retry period to send messages to the keepalive IP address. Enter the retry period as an integer from 2 to 255 seconds. The default is 5 seconds.
For example, to configure a retry period of 60 seconds, enter:
(config-keepalive[keepimages])# retryperiod 60To reset the retry period to its default value of 5, enter:
(config-keepalive[keepimages])# no retryperiodDeactivating a Global Keepalive
Use the suspend command to deactivate the keepalive.
For example:
(config-keepalive[keepimages])# suspendConfiguring a Global Keepalive Type
Use the type command to specify the type of keepalive message assigned to a keepalive. The syntax and options for this keepalive mode command are:
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and reset (RST)).For example, to set the global keepalive keepimages to type tcp, enter:
(config-keepalive[keepimages])# type tcpConfiguring a Global Keepalive URI
Use the uri command to specify the content information for an HTTP global keepalive. Enter the content information for a URI as a quoted text string with a maximum length of 64 characters. Do not include the host information in the string. The CSS derives the host information from the service IP address and the keepalive port number.
When you specify the content information for an HTTP keepalive, the CSS calculates a hash value for the content. If the content information changes, the hash value no longer matches the original hash value and the CSS assumes that the service is down. To prevent the CSS from assuming that a service is down due to a hash value mismatch, specify the keepalive method as head. If you specify a Web page with changeable content and do not specify the keepalive method as head, you must suspend and reactivate the service each time the content information changes.
For example, to specify the content information for the global keepalive, enter:
(config-keepalive[keepimages])# uri "/index.html"To clear the content information for the URI assigned to this keepalive, enter:
(config-keepalive[keepimages])# no uriAssociating a Service with a Global Keepalive
Use the keepalive type named command to associate a service with a global keepalive. The service maintains the global keepalive attributes when you add the service to content rules.
The syntax for this command is keepalive type named name. Specify a global keepalive name to associate the server with a global keepalive.
For example, to associate imageserver1 with global keepalive keepimages, enter:
(config-service[imageserver1])# keepalive type named keepimagesConfiguring Global Keepalive Hash
Use the hash command to override the default MD5 hash for a keepalive. The CSS compares the hash value against the computed hash value of all HTTP GET responses. A successful comparison results in the keepalive maintaining an ALIVE state.
To configure the hash value:
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(config-keepalive[keepimages])# method get(config-keepalive[keepimages])# uri "/testpage.html"(config-keepalive[keepimages])# hash "1024b91e516637aaf9ffca21b4b05b8c"2.
(config)# service imageserver1(config-service[imageserver1])# ip address 10.0.3.21(config-service[imageserver1])# keepalive type named keepimages(config-service[imageserver1])# active3.
(config-keepalive[keepimages])# show keepaliveKeepalives:Name: imageserver1Index: 0 State: ALIVEDescription: Auto generated for service serv1Address: 10.0.3.21 Port:80Type: HTTP GET:/testpage.htmlHash: 1024b91e516637aaf9ffca21b4b05b8cFrequency: 5Max Failures: 3Retry Frequency: 5Dependent Services:4.
(config-keepalive[keepimages])# hash "1024b91e516637aaf9ffca21b4b05b8c"An excerpt of the service configuration from the running-config is shown below.
service imageserver1ip address 10.0.3.21keepalive type httpkeepalive method getkeepalive uri "/testpage.html"keepalive hash "1024b91e516637aaf9ffca21b4b05b8c"activeTo clear a hash value and return to the default hash value, enter:
(config-keepalive[keepimages])# no hashShowing Global Keepalive Configurations
To display global keepalive configurations, use the show keepalive command. To display a list of existing keepalives, enter show keepalive ?.
This command provides the following options:
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For example:
(config)# show keepaliveKeepalives:Name: keepimages Index: 1 State: ALIVE ( ICP Check )Description: This keepalive is for image serversAddress: 172.16.1.7 Port: 80Type: HTTP:HEAD:/index.htmlFrequency: 5Max Failures: 3Retry Frequency: 5Dependent Services: imageserver1Name: rualive Index: 2 State: ALIVEDescription: Auto generated for service serv2Address: 172.16.1.8 Port: 80Type: HTTP:HEAD:/index.htmlFrequency: 5Max Failures: 3Retry Frequency: 5Dependent Services: serv2(config)# show keepalive-summaryKeepalives:Alive1 DOWN 192.25.1.7Alive2 ALIVE 192.25.1.8Table 5-3 describes the fields in the show keepalive output.
Script Keepalives
Script keepalives are scripts that you can create to provide custom keepalives for your specific service requirements. To create the scripts, use the rich CSS Scripting Language that is included in your CSS software. For details on using the CSS Scripting Language, including using socket commands and examples of keepalive scripts, refer to the Content Services Switch Advanced Configuration Guide.
Currently, a CSS provides keepalives for FTP, HTTP, ICMP, and TCP. For information on global keepalives, refer to "Global Keepalive Mode" earlier in this chapter. For information on configuring keepalive messages, refer to "Configuring Keepalives for a Service" earlier in this chapter.
Using script keepalives allow you to extend the CSS keepalive functionality beyond the default keepalives. For example, you can develop a script specifically to connect a CSS to a Post Office Protocol 3 (POP3) mail server.
Once you create a script offline, you can upload it to the CSS and configure the script keepalive option on a service.
The CSS supports a maximum of 255 script keepalives (out of a maximum of 512 keepalive types). If you specify a script to parse the output for each executed command, you can configure only 16 keepalives that use script output.
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Script Keepalive Considerations
When you configure a script keepalive, follow the same general guidelines as those for global keepalive types, with the exceptions noted in these sections. For details on global keepalives, refer to the "Global Keepalive Mode" section earlier in this chapter.
The CSS Scripting Language allows you to pass 128 characters in a quoted argument. Assuming an average of seven characters per argument (plus a space delimiter), you can potentially use a maximum of 16 arguments in one script.
The CSS executes each line in a script keepalive. If your application requires numerous script keepalives (for example, greater than 60), keep each script as short and concise as possible. A smaller script yields much faster script execution results than a larger size script. To maximize system performance, avoid complex protocols or extensive scripts (for example, no database queries, not performing a full login with validation), which can take the CSS longer to execute.
Use the script naming convention of ap-kal-type, so that when you press tab or "?", you can easily see the keepalive scripts available for use. For example, an SMTP script would be named ap-kal-smtp. The script name can have a maximum of 32 characters. The arguments must be in a quoted text string with a maximum of 128 characters.
For the configured script keepalive to find the corresponding script, the script must reside in the /<current running version>/script directory. When you configure a script keepalive, use only script names. (A CSS does not accept path names.) If the script is present elsewhere on the CSS, the script keepalive assumes it does not exist.
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Because a CSS reads an entire script into memory, there is a maximum script keepalive size of 200 KB (approximately 6,000 lines). If a script exceeds this limit, it will not load. This should be more than adequate for all applications. For example, the script keepalives included with your CSS software are approximately 1 KB. To further conserve CSS memory, services can share a common script keepalive so that only one instance of the script needs to reside in memory. However, you must configure the script keepalive for each service where you want the script to run.
To see a complete list of all scripts available in the /<current running version>/script directory, press the Tab key or "?". Optionally, you can type a script name not found in the list, then you can upload the script later. You can manipulate scripts using the archive, clear, and copy commands. You can also upload a script from a local hard drive to the /script directory on the CSS, or download a script from the /script directory on the CSS to a local hard drive.
Configuring Script Keepalives
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Use the keepalive type script command to configure script keepalives. The syntax for this service configuration mode command is:
keepalive type script script_name {"arguments"}{use-output}
The optional use-output keyword allows the script to parse the output for each executed command. This optional keyword allows the use of grep and file direction within a script. You can configure a maximum of 16 script keepalives (out of a maximum of 255 script keepalives) to use script output. By default, the script does not parse the output.
For example, to configure an httplist keepalive, enter:
(config-service[serv1)# keepalive type script ap-kal-httplist "10.10.102.105 /default.htm"In the previous command example, the keepalive command configures the serv1 service keepalive to be of type script with the script name ap-kal-httplist and the arguments "10.10.102.105 /default.htm". The output is not parsed by the script.
To disable a script keepalive on a service, enter:
(config-service[serv1])# keepalive type noneViewing a Script Keepalive in a Service
When you add a script keepalive to a service, the CSS recognizes that the script is the keepalive for the service in the show service screen. The script name appears in the Keepalive field, and any potential arguments appear directly below in the Script Arguments field. If there are no script arguments, then the Script Arguments field does not appear.
For example, enter:
(config-service[serv1])# show serviceName: serv1 Index: 1Type: Local State: AliveRule (10.10.102.105 ANY ANY)Redirect Domain:Keepalive: (SCRIPT ap-kal-httplist 10 3 5)Script Arguments: "10.10.102.105 /default.htm"Script Error: NoneScript Run Time: 1 secondScript Using Output Parsing: NoMtu: 1500 State Transitions: 14Connections: 0 Max Connections: 0Total Connections: 0 Total Reused Conns: 0Weight: 1 Load: 2
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You can also use the show running-config command to display the script keepalive and its arguments.
For example, enter:
(config-service[serv1])# show running-configservice serv1ip address 10.10.102.105keepalive frequency 10keepalive type script ap-kal-httplist "10.10.102.105/default.htm"activeThe example above shows the script keepalive and arguments that have been configured on a service. If no arguments are specified in the script, then the quoted text following the script name will not appear.
Script Keepalive Status Codes
A script can return a status code of zero or non-zero. On a return of non-zero, the CSS flags the service state as Dying or Down; on a return of zero, the CSS flags the service state as Alive. For example, enter:
! Connect to the remote hostsocket connect host einstein port 25 tcp! Purposely failexit script 1Because the above script fails when it executes the exit command, the script returns a non-zero value. By default, the script will fail with a syntax error if the connect command fails. Be sure to check the logic of your scripts to ensure that the CSS returns the correct value.
Script Keepalives and Upgrading WebNS Software
When you upgrade the WebNS software in your CSS, the upgrade process creates a new /<current running version>/script directory. You must copy your custom scripts (including custom script keepalives) to the new /<current running version>/script directory so that the CSS can find them.
Use the following procedure to ensure that your custom script keepalives operate properly after upgrading the software.
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Creating Services
A service can be a destination location or entity that contains and provides Internet content (for example, a server, an application on a server such as FTP, or streaming audio). A service has a name that is associated with an IP address, and optionally, a protocol and a port number.
By creating a service, you identify the service and enable the CSS to recognize it. You can then apply content rules to services that allow the CSS to:
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Enter the service name from 1 to 31 characters. For example, to create service serv1, enter:
(config)# service serv1The CSS transitions into the newly created service mode.
(config-service[serv1])#Configuring Services
The following sections describe how to configure content services.
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Assigning an IP Address to the Service
To enable the CSS to direct requests for content to the appropriate service, you must assign an IP address or range of IP addresses to a service. Assigning an IP address to a service identifies the service to the CSS. When the CSS receives a request for content, it translates the VIP (and potentially, the port) to the service IP address (or addresses) and port.
For example, to assign an IP address to serv1, enter:
(config-service[serv1])# ip address 172.16.1.1The ip address range command allows you to specify a range of IP addresses starting with the IP address you specified using the ip address command. Enter a number from 1 to 65535. The default range is 1. For example, if you enter an IP address of 172.16.1.1 with a range of 10, the IP addresses range from 172.16.1.1 through 172.16.1.10.
When using the ip address range command, use IP addresses that are within the subnet you are using. The CSS does not arp for IP addresses that are not on the circuit subnet. For example, if you configure the circuit for 10.10.10.1/24 and configure the VIP range as 10.10.10.2 range 400, the CSS will not arp for any IP addresses beyond 10.10.10.254. Using the same example only with a VIP range of 200, the CSS will arp for all IP addresses in the range.
For example:
(config-service[serv1])# ip address 172.16.1.1 range 10To restore a service IP address to the default of 0.0.0.0, enter:
(config-service[serv1])# no ip address
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For the CSS to forward requests to a service on any of the addresses in a range, the CSS must successfully arp for the first address in the range. This behavior is independent of keepalives.
Specifying a Port
Use the port command to specify a service TCP/UDP port number or range of port numbers. The TCP or UDP destination port number is associated with a service. Enter the port number as an integer from 0 to 65535. The default is any.
For example:
(config-service[serv1])# port 80To specify a port to be used for keepalives, refer to the service mode keepalive port command.
Use the range option to specify a range of port numbers starting with the port number you specified using the port command. Enter a range number from 1 to 65535. The default range is 1. For example, if you enter a port number of 80 with a range of 10, the port numbers will range from 80 through 89. You can use the port range command only on local (default) services.
For example:
(config-service[serv1])# port 80 10To set the port to the default of any, enter:
(config-service[serv1])# no portSpecifying a Protocol
To specify a service IP protocol, use the protocol command. The default setting for this command is any, for any IP protocol. The options for this command are:
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For example:
(config-service[serv1])# protocol tcpTo set the protocol to the default of any, enter:
(config-service[serv1])# no protocolSpecifying a Domain Name
Use the domain command to specify the domain name to prepend to a requested piece of content when an HTTP redirect service generates an "object moved" message for the service. The CSS uses the configured domain name in the redirect message as the new location for the requested content. The CSS prepends the domain name to the requested URL. If the domain name is not configured, the CSS uses the domain in the host-tag field from the original request. If no host tag is found, the CSS uses the service IP address to generate the redirect.
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Enter the service domain name as an unquoted text string with no spaces and a maximum length of 64 characters.
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For example:
(config-service[serv1])# domain www.arrowpoint.comor
(config-service[serv1])# domain 172.16.3.6To clear the redirect domain for this service, enter:
(config-service[serv1])# no domain www.arrowpoint.comor
(config-service[serv1])# no domain 172.16.3.6Configuring an Advanced Load Balancing String
To specify an advanced load-balancing string for a service, use the string command. Use this command in conjunction with the advanced load-balancing methods url, cookie, or cookieurl. For information on advanced load-balancing methods, refer to the Content Services Switch Advanced Configuration Guide.
Enter a string from 1 to 15 characters. For example:
(config-service[serv1])# string 172.16.3.6To remove a string from a service, enter:
(config-service[serv1])# no stringConfiguring a Service HTTP Cookie
Use the string command to specify the HTTP cookie for the service. The syntax for this service mode command is:
string cookie_name
Enter the cookie_name as an unquoted text string with no spaces and a maximum of 15 characters.
For example:
(config-service[serv1])# string userid3217To remove the cookie for a service, enter:
(config-service[serv1])# no stringConfiguring Weight
To specify the relative weight of the service, use the weight command in service mode. The CSS uses this weight when you configure ACA or weighted roundrobin load balancing on a content rule. By default, all services have a weight of 1. A higher weight will bias flows towards the specified service. To set the weight for a service, enter a number from 1 to 10. The default is 1.
For example:
(config-service[serv1])# weight 2To restore the weight to the default of 1, enter:
(config-service[serv1])# no weight
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Specifying a Service Type
Use the type command to specify the type for a service. If you do not define a type for a service, the default service type is local. The syntax and options for this service mode command are:
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When you add a type redirect service to a content rule, you must also configure an URL to match on the content. For example, "/*" or "/vacations.html".
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For example, to enable the CSS to redirect content requests for serv1, specify redirect in the serv1 content rule:
(config-service[serv1])# type redirectTo restore the service type to the default setting of local, enter:
(config-service[serv1])# no typeHow the CSS Accesses Server Types
When you configure a Layer 3 or 4 content rule, the rule hits the local services. If:
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Redirect services and redirect content strings cannot be used with Layer 3 or 4 rules because they use the HTTP protocol.
When you configure a Layer 5 content rule, the CSS directs content requests to local services. If:
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For information on adding a service to a content rule or adding primary and secondary sorry servers, refer to <Xref_Color>Chapter 7, Configuring Content Rules, the section "Adding Services to a Content Rule".
Configuring Service Access
Use the access command to associate an access mechanism with a service for use during publishing, subscribing, and demand-based replication activities. You must use this command for each service that offers publishing services. This command is optional for subscriber services; the subscriber service inherits the access mechanism from the publisher.
When you use this command to associate an FTP access mechanism with a service, the base directory of an existing FTP record becomes the tree root. To maintain coherent mapping between WWW daemons and FTP daemons, make the FTP access base directory equivalent to the WWW daemon root directory as seen by clients. For information on creating an FTP record, refer to the (config) ftp-record command in Chapter 1, Logging in and Getting Started, the section "Configuring an FTP Record".
Enter the access ftp record as the name of the existing FTP record. Enter an unquoted text string with no spaces.
For example:
(config-service[serv1])# access ftp arrowrecordTo remove a service access mechanism, enter:
(config-service[serv1])# no access ftpConfiguring Service Cache Bypass
Use the cache-bypass command to prevent the CSS from applying content rules to requests originating from a proxy or transparent-cache type service when it processes the requests. By default, no content rules are applied to requests from a proxy or transparent-cache type service.
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For example:
(config-service[serv1])# cache-bypassTo allow the CSS to apply content rules to requests from a proxy or transparent-cache type service, enter:
(config-service[serv1])# no cache-bypassConfiguring Network Address Translation for Transparent Caches
Use the transparent-hosttag command to enable destination Network Address Translation (NAT) for the transparent cache service type.
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For example:
(config-service[serv1])# transparent-hosttagTo disable destination NATing for the transparent cache service type, enter:
(config-service[serv1])# no transparent-hosttagConfiguring a Service to Bypass a Cache Farm
Use the bypass-hosttag command to allow the Client Side Accelerator (CSA) on the CSS to bypass a cache farm and establish a connection with the origin server to retrieve non-cacheable content. The domain name from the host tag field is used to look up the origin IP address on the CSA.
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For example:
(config-service[serv1])# bypass-hosttagTo disable bypassing cache for non-cacheable content, enter:
(config-service[serv1])# no bypass-hosttagConfiguring Keepalives for a Service
Use the keepalive command to configure keepalive message parameters for a service. With keepalive messages you can determine whether or not a service is still functioning. When you configure a keepalive for a service), the CSS periodically sends a message to the service based on the keepalive frequency to determine the state of the service. See the "Configuring Keepalive Frequency" section. The CSS considers the service to be alive when a service responds to the keepalive message.
The CSS transitions the service to the dying state when the service fails to respond to a keepalive message. The CSS tests whether the failed service is functional by sending a keepalive message at time intervals based on the retry period. See the "Configuring Keepalive Retryperiod" section.
The CSS transitions the service to the dead state if the service fails to respond a maximum number of retries to the keepalive message. See the "Configuring Keepalive Maxfailure" section. Then the CSS removes the service from the load-balancing algorithm. The CSS continues to test whether the service is functional at time intervals based on the retry period.
Thus, using the default values of a 5-second keepalive frequency interval, a 5-second retry period interval, and maximum of three failures, a service can transition from the alive state to the dead state in 20 seconds; a 5-second interval between a keepalive response and the initial keepalive failure based on the keepalive frequency, and three failures, each occurring at 5-second intervals based on the retry period.
Keepalives are a valuable and recommended attribute to set for a service. This information enables the CSS to take action rapidly when a service fails. The CSS supports a maximum of 512 keepalives (which can include a maximum of 255 script keepalives). The CSS supports a maximum of 256 keepalives of one type. These keepalives include:
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The options for this service mode command are:
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For more information on these options and associated variables, refer to the following sections.
Configuring Keepalive Frequency
Use the keepalive frequency command to specify the time in seconds between sending keepalives messages to a service. Specify a frequency from 2 to 255 seconds. The default is 5 seconds.
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For example, enter:
(config-service[serv1])# keepalive frequency 15To reset the frequency to its default value of 5, enter:
(config-service[serv1])# no keepalive frequencyConfiguring Keepalive Maxfailure
Use the keepalive maxfailure command to specify the number of times a service can fail to respond to a keepalive message before being considered down. Specify a maximum failure number from 1 to 10. The default is 3.
For example, enter:
(config-service[serv1])# keepalive maxfailure 5To reset the maximum failure number to its default value of 3, enter:
(config-service[serv1])# no keepalive maxfailureConfiguring Keepalive Method
Use the keepalive method command to specify the HTTP keepalive method for a service. The syntax and options for this service mode command are:
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When you specify the content information of an HTTP Uniform Resource Identifier (URI) for an HTTP keepalive, the CSS calculates a hash value for the content. If the content information changes, the hash value no longer matches the original hash value and the CSS assumes that the service is down. To prevent the CSS from assuming that a service is down due to a hash value mismatch, specify the keepalive method as head.
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For example, enter:
(config-service[serv1])# keepalive method getConfiguring Keepalive Port
Use the keepalive port command to specify the port number used for keepalives. Enter the number as an integer from 0 to 65535. The default setting is based on the configured service port number. Otherwise, the default setting is based on the keepalive type. If the keepalive type is:
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For example, to specify port 8080 as the keepalive port for service serv1, enter:
(config-service[serv1])# keepalive port 8080To reset the TCP keepalive port to its default of 0, enter:
(config-service[serv1])# no keepalive portConfiguring Keepalive Retryperiod
Use the keepalive retryperiod command to specify the keepalive retry period for a service. When a service has failed to respond to a given keepalive message (the service has transitioned to the dying state), the retry period specifies how frequently the CSS tests the service to see if it is functional. Enter the retry period as an integer from 2 to 255 seconds. The default is 5 seconds.
For example, to configure a retry period of 60 seconds, enter:
(config-service[serv1])# keepalive retryperiod 60To reset the retry period to its default value of 5, enter:
(config-service[serv1])# no keepalive retryperiodConfiguring Keepalive Type
Use the keepalive type command to specify the type of keepalive message, if any, appropriate for a service or to associate a service with a global keepalive.
The syntax and options for this service mode command are:
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For example, to set serv1 keepalive type to ftp, enter:
(config-service[serv1])# keepalive type ftpConfiguring Keepalive URI
Use the keepalive uri command to specify the HTTP keepalive content information for a service. Enter the the content information of the URI as a quoted text string with a maximum of 64 characters. Do not include the host information in the string. The CSS derives the host information from the service IP address and the keepalive port number.
For example, enter:
(config-service[serv1])# keepalive uri "/index.html"To clear the content information for this keepalive, enter:
(config-service[serv1])# no keepalive uriWhen you specify the content information of a URI for an HTTP keepalive, the CSS calculates a hash value for the content. If the content information changes, the hash value no longer matches the original hash value and the CSS assumes that the service is down. To prevent the CSS from assuming that a service is down due to a hash value mismatch, define keepalive method as head. The CSS does not compute a hash value for this type of keepalive.
If you specify a Web page with changeable content and do not specify the head keepalive method, you must suspend and reactivate the service each time the content changes.
Configuring Keepalive Hash
Use the hash command to override the default MD5 hash for a keepalive. The CSS compares the hash value against the computed hash value of all HTTP GET responses. A successful comparison results in the keepalive maintaining an ALIVE state.
To configure the hash value:
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(config)# service serv1(config-service[serv1])# ip address 10.0.3.21(config-service[serv1])# keepalive type http(config-service[serv1])# keepalive method get(config-service[serv1])# keepalive uri "/testpage.html"(config-service[serv1])# keepalive hash "1024b91e516637aaf9ffca21b4b05b8c"(config-service[serv1])# active2.
(config-service[serv1])# show keepaliveKeepalives:Name: serv1Index: 0 State: ALIVEDescription: Auto generated for service serv1Address: 10.0.3.21 Port: 80Type: HTTP:GET:/testpage.htmlHash: 1024b91e516637aaf9ffca21b4b05b8cFrequency: 5Max Failures: 3Retry Frequency: 5Dependent Services:3.
(config-service[serv1])# keepalive hash "1024b91e516637aaf9ffca21b4b05b8c"An excerpt of the service configuration from the running-config is shown below.
service serv1ip address 10.0.3.21keepalive type httpkeepalive method getkeepalive uri "/testpage.html"keepalive hash "1024b91e516637aaf9ffca21b4b05b8c"activeTo clear a hash value and return to the default hash value, enter:
(config-service[serv1])# no keepalive hashShowing Keepalive Configurations
To display global keepalive configurations, use the show keepalive command. To display a list of existing keepalives, enter show keepalive ?. This command provides the following options:
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For example, enter:
(config)# show keepaliveKeepalives:Name: keepimages Index: 1 State: ALIVE ( ICP Check )Description: Auto generated for service imageserver1Address: 172.16.1.7 Port: 80Type: HTTP:HEAD:/index.htmlFrequency: 5Max Failures: 3Retry Frequency: 5Dependent Services: imageserver1Name: rualive Index: 2 State: ALIVEDescription: Auto generated for service serv2Address: 172.16.1.8 Port: 80Type: HTTP:HEAD:/index.htmlFrequency: 5Max Failures: 3Retry Frequency: 5Dependent Services: serv2(config)# show keepalive-summaryKeepalives: keepimages ALIVE 172.16.1.7rualive ALIVE 172.16.1.8Configuring Maximum TCP Connections
To define the maximum number of TCP connections on a service, use the max connections command. Enter the maximum number of connections from 0 to 65535. The default is 0, which indicates that there is no limit on the number of connections.
(config-service[serv1])# max connections 7To set the maximum TCP connections to the default of 0, enter:
(config-service[serv1])# no max connections
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Activating a Service
Once you configure a service, you must activate it to enable the CSS to access it for content requests. Activating a service puts it into the resource pool for load-balancing content requests and starts the keepalive function.
The following command activates service serv1:
(config-service[serv1])# activeSuspending a Service
Suspending a service removes it from the pool for future load-balancing content requests. Suspending a service does not affect existing content flows, but it prevents additional connections from accessing the service for its content. You may want to suspend a service prior to performing maintenance on the service. The following command suspends service serv1:
(config-service[serv1])# suspend
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Removing a Service
When you remove a service, the CSS:
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Removing a Service From a Content Rule
To display a list of services added to a content rule, enter the remove service ? command from the specific owner-content mode. For example:
(config-owner-content[arrowpoint-rule1])# remove service ?server1server3To remove service server1 from owner arrowpoint content rule rule1, enter:
(config-owner-content[arrowpoint-rule1])# remove service server1Removing a Service From a Source Group
To remove a service from a source group, use the remove service command. To display a list of services added to a source group, enter the remove service ? command from the specific group mode. For example:
(config-group[ftpgroup])# remove service ?server7serviceftpFor example, to remove service serviceftp from source group ftpgroup, enter:
(config-group[ftpgroup])# remove service serviceftpShowing Service Configurations
Before activating a service, you may want to display the service configuration to ensure that all the parameters are correct. The show service command enables you to display information for a specific service or all services currently configured in the CSS, depending on the location from where you issue the command.
You can issue the following show service commands from any mode:
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From a specific service mode, the show service command displays configuration information only for that service. When you issue this command from any other mode, it displays configuration information for all services.
For example:
(config)# show serviceName: s1 Index:Type: Local State: AliveRule: (192.168.101.15 ANY ANY )Keepalive: (ICMP 5 3 5 )Mtu: 1500 State Transitions: 14Connections: 0 Max Connections: 0Total Connections: 0 Total Reused Conns: 0Weight: 1 Load: 2The show service summary command displays a summary of all service currently configured. For example:
(config)# show service summaryService Name State Conn Weight Avg Long StateLoad Load Transitionsserv17 DOWN 0 1 254 254 1serv18 ALIVE 0 0 254 0 5NS6 ALIVE 0 0 254 0 3SL3@192.16.10.25 ALIVE 0 1 212 254 1To display configuration information for all services, enter:
# show serviceTo display information for a specific service, enter the show service command with the service name. For example:
# show service serv86If you are in service mode, to display the configuration information for the current service, enter:
(config-service[serv86])# show service
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Table 5-4 describes the fields in the show service output.
Where to Go Next
For information on creating and configuring owners, refer to Chapter 6, Configuring Owners.
