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CSS Advanced Configuration Guide (Software Version 7.10)
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Index
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About This Guide
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Configuring the CSS Domain Name Service
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Configuring DNS Sticky
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Configuring a CSS as a Content Routing Agent
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Configuring a Client Side Accelerator
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Configuring Network Proximity
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Configuring VIP and Virtual IP Interface Redundancy
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Configuring Redundant Content Services Switches
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Configuring Content Replication
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Configuring SSL Termination on the CSS
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Configuring Firewall Load Balancing
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Using the CSS Scripting Language
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Table Of Contents
Entering Your Proximity License Keys
Proximity Database License Key
Proximity Domain Name Server License Key
Network Proximity Configuration Quick Start
Proximity Database Configuration Quick Start
Proximity Domain Name Server Configuration Quick Start
Configuring a Proximity Database
Removing an APP-UDP Options Record
Showing APP-UDP Configurations
Enabling the Proximity Database
Flushing Proximity Assignments
Configuring Proximity Time to Live
Storing the Proximity Database
Retrieving the Proximity Database
Clearing the Proximity Database
Configuring the Proximity Probe Module
Configuring the Proximity Probe Module Method
Specifying the Proximity Probe Module Samples
Configuring the Proximity Probe Module Metric Weighting
Configuring the Proximity Probe Module Interval
Specifying Proximity Probe Module TCP-ports
Tiered Network Proximity Example
Displaying Proximity Database Configurations
Showing the Proximity Database
Showing Proximity Zone Statistics
Showing Proximity Probe Module Statistics
Configuring a Proximity Domain Name Server
Enabling the Proximity Domain Name Server
Disabling the Proximity Domain Name Server
Clearing the DNS Server Statistics
Enabling the Proximity Lookup Cache
Removing Entries from the Proximity Lookup Cache
Displaying Proximity Domain Name Server Configurations
Displaying the Proximity Cache
Displaying DNS-Record Statistics
Displaying DNS-Record Keepalives
Displaying DNS-Record Proximity
Displaying DNS Server Information
Configuring Network Proximity
Network Proximity provides a content delivery solution that significantly improves network performance. This optional software feature uses a CSS 11150 configured as a database that is populated by actively probing the network to determine the proximity of clients and services. Additional CSSs (any model) perform database lookup requests and domain name resolution to determine the most proximate service for a client.
This chapter describes the Network Proximity feature and provides related configuration information in the following sections:
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Entering Your Proximity License Keys
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Caution
Entering Your Proximity License Keys
All CSSs include the Standard feature set. If you are upgrading your CSS with the Enhanced feature set or you have purchased the optional Proximity Database software feature, enter the appropriate software license key at the command line using the license command for the optional feature. If you ordered your software option with your CSS, you will find the option license key on a card in an envelope included in your CSS Accessory kit. If you ordered your software option after receipt of your CSS, the license key was mailed to you.
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Proximity Database License Key
Caution
Enter the license key for the Proximity Database (PDB) software option on each CSS 11150 with 256 MB of memory that you want to use exclusively as a PDB.
To install the PDB software license key:
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# license2.
Enter the Software License Key (q to quit): nnnnnnnnnnnnThe PDB license key is now properly installed.
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Proximity Domain Name Server License Key
Enter the license key for the Enhanced feature set, which includes the Proximity Domain Name Server (PDNS) feature, on each CSS (any model) that you want to use exclusively as a PDNS. For example:
# licenseAt the prompt, enter the 12-digit Enhanced feature set software license key. For example:
Enter the Software License Key (q to quit):nnnnnnnnnnnnNetwork Proximity Overview
Proximity represents a topological relationship between a client and content services. In a network topology perspective, as used in this chapter, proximity refers to connecting a client to the most proximate service based on a measurement of the round-trip time (RTT) between the client's local DNS server and a proximity zone (see Figure 5-1).
Figure 5-1 Simplified Example of Network Proximity
In Figure 5-1, the lowest RTT value is returned from Zone 0. Therefore, Network Proximity would link the client to a service located in Zone 0, regardless of the physical location of the client. The three zones communicate with each other using the Application Peering Protocol (APP). For details on APP, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Configuring Application Peering Protocol".
The major components and concepts in Network Proximity are:
Proximity Database
A Proximity Database (PDB) is a dedicated CSS 11150 with 256 MB of memory and is configured as a PDB using the optional Proximity Database software feature. (For details on configuring a CSS 11150 as a PDB, see "Configuring a Proximity Database" later in this chapter.) One PDB and one or more Proximity Domain Name Servers (PDNSs) and data centers (server farms or lower-level DNS servers) define a subset of the Internet address space called a proximity zone. (For details on proximity zones, see "Proximity Zones" later in this chapter.)
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Network Proximity, as implemented on a CSS, uses a topology-testing technique that actively probes clients to determine the relative location of clients and services. To accomplish this, a PDB uses ICMP and TCP requests to actively probe a client's local DNS server for proximity information. The PDB analyzes the probe responses, then stores the resulting network RTT metrics (in milliseconds) in its database.
When a PDNS sends the PDB a proximity lookup request for a client using APP-UDP, the PDB compares the RTT metrics for that client and responds immediately with an ordered zone index, a list of proximity zones in preferred order by RTT. The PDNS then uses the ordered zone index, along with domain name records and keepalive information, to determine the most proximate service for the client.
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A PDB communicates with PDBs in other zones using a peer mesh, implemented with APP. (For details on APP, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Configuring Application Peering Protocol".) This enables PDBs to periodically "learn" the latest RTT metrics information from the other PDBs in the peer mesh to ensure that a client is connected to the most proximate service. Each PDB contains a metric for every source block of interest in each proximity zone. A source block of interest is a CIDR block that contains a client's local DNS server.
Proximity Domain Name Server
A Proximity Domain Name Server (PDNS) is any CSS that is running the Enhanced feature set and is configured as a PDNS using the Enhanced software feature set. (For details on configuring a CSS as a PDNS, see "Configuring a Proximity Domain Name Server" later in this chapter.) A PDNS performs PDB lookup requests, using Application Peering Protocol-User Datagram Protocol (APP-UDP), in response to DNS requests that the PDNS receives from a client's local DNS server. The PDB responds to these lookup requests immediately with the ordered zone index. The PDNS uses the ordered zone index along with domain name records and keepalive information to make an authoritative DNS response to the client's local DNS server.
The primary task of a PDNS is to respond to DNS requests based on proximity and domain availability. However, the CSS is not excluded from supporting local content rules and services, as well as non-Proximity-based DNS load balancing. These non-PDNS activities will affect the CSS's performance as a PDNS and the PDNS activities will affect the CSS's performance as a content services switch, depending on the PDNS's load.
Every proximity zone contains one or more PDNSs, up to a maximum of four generating their maximum request rates per zone. If the PDNSs are not fully loaded, you can configure additional PDNSs in a zone. Each PDNS within a zone acts as an authoritative DNS server for domains representing data centers. A data center can be a server farm attached directly to a CSS or can be a lower-level DNS server (which may or may not be a CSS) representing a server farm. You configure the domains statically on each PDNS.
Each PDNS maintains the following records for the domains configured on it:
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A PDNS updates its domain records continually through keepalive messages (using ICMP or APP-UDP) that it sends to its locally configured virtual IP addresses (VIPs) and data centers. The PDNS uses the keepalive responses to track the load (kal-ap keepalive only, see below) and availability of locally configured domains. Each PDNS in a proximity zone shares its domain information with other PDNSs in each zone using an APP peer mesh (see "Peer Mesh" later in this chapter). There is no communication between PDNSs within the same zone, and each PDNS communicates with one PDNS per zone.
For the optional CSS keepalive type (kal-ap), the keepalive client resides on the PDNS, while the keepalive daemon resides on any CSS-based data center that is the configured recipient of A-records or NS-records as configured on the controlling PDNS. The keepalive daemon extracts the load information of the specified domain names and returns them to the PDNS. This load information originates from:
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Proximity Zones
A proximity zone is a logical grouping of network devices that consists of one PDB, one or more PDNSs, and services. Although a zone is really a logical subset of the Ipv4 address space, a zone can also be geographically related to a continent, a country, or a major city. Refer to Figure 5-2.
For example, you can create proximity zones to group geographically distinct network devices. A proximity zone containing data centers in the United States logically groups nodes within a distinct geographical area. Another proximity zone may logically group nodes and data centers in Europe, for example. Zones are numbered beginning with zero.
Figure 5-2 Example of Network Proximity Zones
Peer Mesh
To communicate proximity information between proximity zones, Network Proximity uses APP to create a peer mesh. A peer mesh is an abstraction layer that uses APP to provide common functions (for example, zone configuration information) between Network Proximity devices. A PDB mesh allows PDBs to communicate with one another across proximity zones to share proximity metrics. A PDNS mesh allows a PDNS in one zone to communicate with one other PDNS in each proximity zone to share domain records and keepalive information. For details on APP, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Configuring Application Peering Protocol".
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Network Proximity Example
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The following example illustrates a single point-in-time request from a client. Refer to Figure 5-3 for an illustration of the following steps.
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Figure 5-3 Two-Zone Network Proximity Example
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Network Proximity Configuration Quick Start
Table 5-1 and Table 5-2 provide a quick overview of the steps required to configure the PDB and PDNS, respectively. Each step includes the CLI command required to complete the task. For a complete description of each feature and all the command options, refer to the sections following Table 5-1 and Table 5-2.
Proximity Database Configuration Quick Start
Table 5-1 provides an overview of the steps required to configure a PDB on a dedicated CSS 11150 with 256 MB of RAM. Follow these steps to configure PDB-0 located in Proximity Zone 0 in Figure 5-3. Use the CLI commands outlined in the table to configure basic PDB settings.
Table 5-1 PDB Configuration Quick Start
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(config)#2.
(config)# app-udp3.
(config)# app4.
(config)# app session 200.16.2.35.
(config)# proximity db 0 tier1 "pdb-usa"
Proximity Domain Name Server Configuration Quick Start
Table 5-2 provides an overview of the steps required to configure PDNS-0 located in Proximity Zone 0 in Figure 5-3. Use the CLI commands outlined in the table to configure basic PDNS settings.
Table 5-2 PDNS Configuration Quick Start
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(config)#2.
(config)# app-udp3.
(config)# app4.
(config)# dns-server zone 0 tier1 "usa" 172.16.2.25.
(config)# dns-server6.
(config)# app session 200.16.2.57.
(config)# dns-record a www.home.com 123.45.6.7 0 single kal-icmp8.
(config)# dns-record ns www.work.com 123.45.6.8 0 single kal-icmp9.
Configuring a Proximity Database
Caution
A PDB is a dedicated CSS 11150 with 256 MB of RAM and configured as a Proximity Database. Configure one PDB in each Network Proximity zone you want to create. Once configured, a PDB stores network topology information used to determine the relationship between proximity zones and a client that requests a service. The PDB populates its database through active probing of clients (local DNS servers) and sharing information with PDBs in other zones using an APP mesh. The PDB also responds to lookup requests from each PDNS configured in a zone using APP-UDP.
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Configuring a PDB requires the following two tasks:
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Optionally, you can configure additional PDB parameters as follows:
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Configuring APP-UDP and APP
Network Proximity uses the Application Peering Protocol-User Datagram Protocol (APP-UDP) to exchange proximity information between a PDB and a PDNS, and between a PDNS and services. APP-UDP is a connectionless form of APP.
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Configuring APP-UDP for proximity requires you to enable APP-UDP.
Optionally, you can configure additional APP-UDP parameters as follows:
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Enabling APP-UDP
Use the app-udp command to configure APP-UDP datagram messaging on the PDB and all PDNSs in each zone. This command is available in global configuration mode.
The app-udp command supports the following options:
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For example:
(config)# app-udpTo disable APP-UDP messaging, enter:
(config)# no app-udpSecuring APP-UDP Datagrams
Use the app-udp secure command to require that all incoming APP-UDP datagrams be encrypted. Encryption prevents unauthorized messages from entering the CSS. This command is used in conjunction with the app-udp options command that specifies secure messages that the CSS accepts.
Caution
The syntax for this global configuration mode command is:
app-udp secure
The following example illustrates the use of the app-udp secure command. In this example, this configuration allows only incoming traffic from IP address 200.16.2.3 encrypted with the password mysecret. The password is an unquoted text string with a maximum of 31 characters. There is no default.
For example:
(config)# app-udp(config)# app-udp secure(config)# app-udp options 200.16.2.3 encrypt-md5hash mysecretTo restore the default behavior of the CSS to accept all APP-UDP datagrams, enter:
(config)# no app-udp secureSpecifying APP-UDP Options
Use the app-udp options command to associate APP-UDP options with an IP address. The CSS applies the options to packets sent to the destination address or applies them when the CSS receives datagrams with a matching source IP address. You can configure the IP address to 0.0.0.0 to apply a set of security options to all inbound and outbound datagrams that are not more specifically configured. Using the IP address 0.0.0.0 allows you to set a global security configuration that may be applied to an arbitrary number of peers. This command is available in configuration mode.
The syntax for this global configuration mode command is:
app-udp options ip_address encrypt-md5hash secret
The app-udp options command contains optional fields that allow you to encrypt datagrams. This encryption method applies to datagrams sent and received over an IP address. Encryption options include:
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The following example configures the IP address with the encrypt-md5hash global option. Datagrams sent to or received from 200.16.2.3 are encrypted with the password mysecret. All other datagrams received or transmitted, are subjected to the default encryption secret anothersecret.
For example:
(config)# app-udp(config)# app-udp options 200.16.2.3 encrypt-md5hash mysecret(config)# app-udp options 0.0.0.0 encrypt-md5hash anothersecretRemoving an APP-UDP Options Record
Use the no app-udp options command to remove an options record. This command includes an ip_address option to enable the CSS to associate an IP address with a group of options. Enter the address in dotted-decimal notation (for example, 200.16.2.3).
The syntax for this global configuration mode command is:
no app-udp options ip_address
For example:
(config)# no app-udp options 200.16.2.3Specifying the APP-UDP Port
Use the app-udp port command to set the UDP port number that listens for APP-UDP datagrams. The app-udp port command includes the port_number variable, which specifies the UDP port number. Enter a value of 1025 to 65535. The default is 5002.
The syntax for this global configuration mode command is:
app-udp port port_number
For example:
(config)# app-udp port 2To restore the UDP port number to its default value of 5002, enter:
(config)# no app-udp port
Note
Showing APP-UDP Configurations
Use the show app-udp command to display APP-UDP global statistical information and security configuration settings.
The options for the show app-udp command are:
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For example, to display statistical information about the operation of APP-UDP, enter:
(config)# show app-udp globalTable 5-3 describes the fields in show app-udp global output.
For example, to display the current security configuration settings for APP-UDP, enter:
(config)# show app-udp secureTable 5-4 describes the fields in the show app-udp secure output.
Enabling the Proximity Database
Note
Use the proximity db command to enable the PDB on a dedicated CSS 11150 with 256 MB of RAM.
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The syntax for this global configuration mode command is:
proximity db zoneIndex {tier1|tier2} {"description"}}
The proximity db command supports the following variables and options:
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For example:
(config)# proximity db 1 tier1 "pdb-usa"To disable the Proximity Database, enter:
(config)# no proximity dbAssigning Proximity Metrics
Use the proximity assign command to provide a local metric or to provide metrics (in milliseconds) for all proximity zones. The proximity assign command overrides the default metric determination processes. This command allows you to turn off probe traffic to Classless Inter-Domain Routing (CIDR) blocks.
When you use this command, Network Proximity does not perform active probing of the assigned block. Assigned information is shared with all PDBs in the PDB mesh. You can use this Network Proximity command only on a PDB.
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The syntax for this SuperUser configuration mode command is:
proximity assign ip_address ip_prefix ["local_metric"|"metric_list"]
The proximity assign command supports the following variables:
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For example, the following command uses the local_metric variable to assign a value of 200 to all client DNS addresses included in the range 172.23.5.7/24.
# proximity assign 172.23.5.7/24 "200"This command uses the metric_list variable to assign a value of 200 ms to proximity zone 0, does not configure zone 1 (specified by a value of zero), and assigns a value of 50 ms to zone 2.
# proximity assign 172.23.5.7/24 "200 0 50"Flushing Proximity Assignments
Use the proximity assign flush command to remove existing proximity assignments configured with the proximity assign command. You can use this Network Proximity command only on a PDB.
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The syntax for this SuperUser configuration mode command is:
proximity assign flush {ip_address ip_prefix}
The proximity assign flush command supports the following variables:
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For example:
# proximity assign flush 172.23.5.7/24Configuring Proximity Time to Live
Use the proximity ttl command to set the TTL value, in minutes, for each PDB response. This value tells the PDNS how long to cache the PDB response. You can use this Network Proximity command only on a PDB.
The syntax for this global configuration mode command is:
proximity ttl assigned | probe minutes
The options for this global configuration mode command are:
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For example:
(config)# proximity ttl assigned 25To reset the TTL value to its default, enter:
(config)# no proximity ttl probe
Note
Storing the Proximity Database
Use the proximity commit command to write a portion or all of the proximity database to a file in the log directory on the CSS disk or to a file on an FTP server. This command is useful for exporting the database so that you can view, modify, or recover information in the PDB. The database output contains metrics for all proximity zones, the current advertisement state, and hit counts.
To retrieve the database log file, use the proximity retrieve command. You can use this Network Proximity command only on a PDB.
By default, when you enter this command without any of its options, it writes the entire database to an XML-formatted file named proximity.db in the log directory on the CSS disk. You can optionally specify that the database be encoded using compact binary encoding. You can also specify that the database be written to a file on an FTP server.
The syntax for this SuperUser command is:
proximity commit {ip_address ip_prefix|entire-db {ftp ftp_record ftp_filename {bin}|log filename {bin}}}
The proximity commit command supports the following variables and options:
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For example:
# proximity commit 172.23.5.7/24 xmlRetrieving the Proximity Database
Use the proximity retrieve command to load a PDB from disk or an FTP server. Proximity metrics loaded from the database file replace any overlapping entries existing in the database and supplement any non-overlapping database entries. You can use this Network Proximity command only on a PDB.
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The proximity retrieve command distinguishes between XML encoded and binary database formats automatically.
The syntax for this SuperUser command is:
proximity retrieve {ftp ftp_recordname ftp ftp_filename|log filename}
The proximity retrieve command supports the following variables:
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For example:
# proximity retrieve ftp proxconfig proxconfignewRefining Proximity Metrics
Use the proximity refine and the proximity refine once commands to initiate the continuous or single refinement, respectively, of metric entries in the PDB. Refinement updates the metric entries for all clients in the database to reflect conditions that exist at a particular point in time. You can use these Network Proximity commands only on a PDB.
When you issue the proximity refine command, the PDB probes all existing clients in the database periodically based on the size of the database and the database hit counts for the clients. The PDB organizes clients into three groups by hit count: N1, N2, and N3. The PDB probes N1 more frequently than N2, and N2 more frequently than N3. The percentage of time spent probing N1, N2, and N3 is approximately 45%, 35%, and 20%, respectively.
When you issue the proximity refine once command, the PDB probes all existing clients in the database only once.
The syntax for these SuperUser configuration mode commands are:
proximity refine
proximity refine once
To stop a refinement in progress, enter:
# no proximity refineUsing Proximity Reprobe
Use the proximity reprobe command to send additional probes to existing IP addresses in the proximity database once. You can use this Network Proximity command only on a PDB. You can use the proximity reprobe command with the proximity refine commands.
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The syntax for this SuperUser configuration mode command is:
proximity reprobe ip_address {ip_prefix}
The proximity reprobe command supports the following variables:
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For example:
# proximity reprobe 172.23.5.7/24Clearing the Proximity Database
Use the proximity clear command to remove entries from the proximity database.
Caution
The syntax for this SuperUser command is:
proximity clear ip_address ip_prefix
The proximity clear command supports the following variables:
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Configuring the Proximity Probe Module
The Proximity Probe Module is responsible for sending ICMP and TCP probes to clients based on PDNS lookup requests to the PDB and refinement settings. Refer to the following sections to configure the Proximity Probe Module:
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Configuring the Proximity Probe Module Method
Use the proximity probe rtt method command to configure the primary and secondary methods used for proximity metric discovery. You can use this Network Proximity command only on a PDB.
The syntax for this global configuration mode command is:
proximity probe rtt method [icmp {tcp}|tcp {icmp}]
The proximity probe rtt method command supports the following options:
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For example:
(config)# proximity rtt method icmpSpecifying the Proximity Probe Module Samples
Use the proximity probe rtt samples command to configure the number of ICMP requests to send for each client probe. You can use this Network Proximity command only on a PDB.
Note
The syntax for this global configuration mode command is:
proximity probe rtt samples number
The number variable specifies the default number of ICMP echo requests used for averaging during an initial probe. Enter a number from 1 to 30. The default is 2.
For example:
(config)# proximity probe rtt samples 5To reset the number of ICMP echo requests to its default value of 2, enter:
(config)# no proximity probe rtt samplesConfiguring the Proximity Probe Module Metric Weighting
Use the proximity probe rtt metric-weighting command to configure the percentage of the previously stored metric value in the database that is used to determine the new metric value. This command allows the PDB to smooth network metric variation caused by network congestion, flash crowds, and so on. You can use this Network Proximity command only on a PDB.
The syntax for this global configuration mode command is:
proximity probe rtt metric-weighting number
The number variable specifies the percentage of the previous metric value used. Enter a number from 0 to 99. The default is 0.
For example:
(config)# proximity probe rtt metric-weighting 10For this example, suppose the previously stored metric value for a client's local DNS server is 40 and the current metric value is 50. If you issue the command above, the PDB adds 10% of the previous metric value (0.10 x 40) to 90% of the current metric value (0.90 x 50) to determine the new metric value. So, the new metric value would be 49. A number value of 50 causes the PDB to average the previous and current metric values.
To reset this command to its default value of 0, enter:
(config)# no proximity probe rtt metric-weightingConfiguring the Proximity Probe Module Interval
Use the proximity probe rtt interval command to configure the delay in seconds between ICMP samples. You can use this Network Proximity command only on a PDB.
The syntax for this global configuration mode command is:
proximity probe rtt interval seconds
The seconds variable identifies the length of time (in seconds) to wait between ICMP samples. Use a range between 1 to 10. The default is 1.
For example:
(config)# proximity probe rtt interval 5To reset the delay between samples to its default value of 1 second, enter:
(config)# no proximity probe rtt intervalSpecifying Proximity Probe Module TCP-ports
Use the proximity probe rtt tcp-ports command to configure the probe ports for TCP proximity metric discovery. You can use this Network Proximity command only on a PDB.
The syntax for this global configuration mode command is:
proximity probe rtt tcp-ports port_number1 {port_number2 {port_number3 {port_number4}}}
Define the port number to be tried, in order of precedence. Enter a number from 1 to 65535 to enable a port. The defaults for the various port numbers include:
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To reset the probe ports to their default values, enter:
(config)# no proximity probe rtt tcp-portsUsing Network Proximity Tiers
The following sections describe the advanced Network Proximity concept of tiers. Network Proximity uses tiers to further expand the proximity architecture by allowing you to create more distinct network zones and subzones.
Proximity Tiers
Sharing information among multiple PDBs may result in the management of a very large data set. As you add more proximity zones to the network, Network Proximity scales to provide more distinct network zones, allowing zones or subzones to exist within other zones. Network Proximity treats these zones as:
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In a tiered Network Proximity model, the owner of the name server record is a nested PDNS that is communicating with a nested PDB located within the Level 2 proximity subzone.
Tiered Network Proximity Example
In , a two-tiered configuration example illustrates how you can use tiers to group more specific network proximity zones. The proximity zone that encompasses all network devices within the United States is broken down further to include an additional tier that comprises the more specific geographical proximity zones, East Coast and West Coast.
By adding a tier to this configuration, the capacity of Network Proximity is extended by creating two subzones (Zones 0.1 and 0.2) that include additional PDBs, PDNSs, and data centers. In this way, you can scale Network Proximity to meet your users' needs with increased proximity specificity and thereby increase network performance.
The following steps describe how Network Proximity determines the most proximate service for a client requesting the domain www.work.com. Refer to Figure 5-4.
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Figure 5-4 Tiered Network Proximity Configuration
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Displaying Proximity Database Configurations
The CSS provides a comprehensive set of Network Proximity show commands that display information about the PDB. Use the show proximity command to display PDB configuration or session information. Refer to the following sections for information on using Proximity Database show commands:
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Showing the Proximity Database
Use the show proximity command to display an activity summary of the proximity database. This command functions only on a PDB.
For example:
# show proximityTable 5-5 describes the fields in the show proximity output.
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Showing Proximity Metrics
Use the show proximity metric command to display metrics (in milliseconds) associated with a client's local DNS server IP address. This command is available on a PDNS and a PDB.
The syntax and options for this global configuration mode command are:
show proximity metric ip_address {ip_prefix {aggregate}}
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For example, to view the proximity metrics associated with the client IP address of 172.23.5.7 and an IP prefix of 24, enter:
(config)# show proximity metric 172.23.5.7/24In the PDB, the RTT metrics are sorted by proximity zone. In the PDNS, the metrics are sorted by RTT. An asterisk next to a zone indicates the zone where the command was issued.
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Table 5-6 describes fields in the show proximity metric output.
Showing Proximity Statistics
Use the show proximity statistics command to display statistics associated with client IP addresses. This Network Proximity command is only available on the PDB.
The syntax and options for this global configuration mode command are:
show proximity statistics ip_address {ip_prefix {aggregate}}
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For example, to view the proximity statistics associated with the client IP address of 10.1.0.0 and an IP prefix of 16, enter:
(config)# show proximity statistics 10.1.0.0/16Table 5-7 describes fields in the show proximity statistics output.
Showing Proximity Refinement
Use the show proximity refine command to display information pertaining to entries being refined in the PDB. This Network Proximity command is only available on a PDB. For an explanation of the N1, N2, and N3 groups mentioned below, see "Refining Proximity Metrics" earlier in this chapter.
For example:
(config)# show proximity refineTable 5-8 describes fields in the show proximity refine output.
Showing Proximity Assignments
Use the show proximity assign command to display the user-assigned metric values (in milliseconds) of all proximity zones or for a configured IP address range.
The syntax and variables for this global configuration mode command are:
show proximity assign {ip_address ip_prefix}
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For example, to view the metric assignments for all IP addresses within the range of 200.16.0.0 to 200.16.255.255, enter:
(config)# show proximity assign 172.23.5.7/16Table 5-9 describes the fields in the show proximity assign output.
Showing Proximity Zones
Use the show proximity zone command to view the state information for each proximity zone, excluding the local proximity zone. This command is similar to the show zone command for the PDNS; however, the show proximity zone command provides information from the perspective of the PDB. This Network Proximity command is available only on a PDB.
The syntax for this global configuration mode command is:
show proximity zone {number}
Use the number variable to display the state information for a specific proximity zone. Enter a zone number from 0 to 15.
For example, to display the state information for proximity zone 1, enter:
(config)# show proximity zone 1Table 5-10 describes the fields in the show proximity zone output.
Showing Proximity Zone Statistics
The show proximity zone statistics command displays information about the APP peer mesh blocks sent and received for a peer for all proximity zones.
The syntax for this global configuration mode command is:
show proximity zone statistics {number}
Use the number variable to display statistics for a specific proximity zone. Enter a zone number from 0 to 15.
For example, to display the peer block information for zone 1, enter:
(config)# show proximity zone statistics 1Table 5-11 describes the fields in the show proximity zone statistics display.
Showing Proximity Probe Module Statistics
Use the show proximity probe rtt statistics command to view the Round Trip Time (RTT) probe module statistics.
The syntax for this global configuration mode command is:
show proximity probe rtt statistics
For example:
(config)# show proximity probe rtt statisticsTable 5-12 describes the fields in the show proximity probe rtt statistics output.
Configuring a Proximity Domain Name Server
The Proximity Domain Name Server (PDNS) is an authoritative DNS server that uses information from the Proximity Database (PDB) to resolve DNS requests based on an ordered zone index. As an authoritative DNS server, the PDNS uses domain records to map a given domain to an IP address or to a lower-level DNS server. You can configure a total of 1024 unique domain names for all PDNSs in a proximity mesh per proximity level. The same domain names can appear in all zones and on multiple PDNSs within a zone.
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Configuring a PDNS involves the following required tasks:
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Optionally, you can perform the following PDNS-related tasks:
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Configuring APP-UDP and APP
Network Proximity uses the Application Peering Protocol-User Datagram Protocol (APP-UDP) to exchange proximity information between a PDB and a PDNS, and between a PDNS and services. APP-UDP is a connectionless form of the Application Peering Protocol (APP). For details, see "Configuring APP-UDP and APP" earlier in this chapter.
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Enabling the Proximity Domain Name Server
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Use the dns-server zone and dns-server commands to enable the PDNS. The syntax for this global configuration mode command is:
dns-server zone zone_index {tier1|tier2 {"description" {ip_address {round-robin|prefer-local}}}}
The dns-server zone command supports the following variables and options:
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For example:
(config)# dns-server zone 1 tier1 "pdns-usa" 172.16.2.2Configuring Domain Records
Use the dns-record command and its options to create a domain record on the PDNS. The PDNS uses two types of domain records to map a domain name to an IP address or to another DNS server:
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For details on configuring the dns-record command, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Configuring Domain Records".
Disabling the Proximity Domain Name Server
Use the no dns-server zone command to disable the PDNS Proximity functions by removing the dns-server zone command configuration.
Disabling the PDNS:
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After issuing the no dns-server zone command, you can still use the PDNS as a DNS server.
For example:
(config)# no dns-server zone
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Clearing the DNS Server Statistics
Use the dns-server zero command in global configuration mode to set the DNS server request and response statistics displayed by the show dns-server command to zero.
For example:
(config)# dns-server zeroEnabling the Proximity Lookup Cache
Use the proximity cache-size command to modify the size of the proximity lookup cache. The PDNS uses the proximity lookup cache to store PDB responses. The proximity lookup cache allows the PDNS to resolve proximity decisions faster by allowing a local lookup.
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The syntax for this global configuration mode command is:
proximity cache-size cache_size
The proximity cache-size command includes a cache size variable that specifies the size of the proximity lookup cache. Enter a value between 0 and 48,000. Entering a value of 0 disables the proximity lookup cache. Modifying the cache size results in flushing the existing entries. The default cache size is 16,000.
For example:
(config)# proximity cache-size 30000To restore the default cache size (16,000 entries), enter:
(config)# no proximity cache-sizeRemoving Entries from the Proximity Lookup Cache
Use the proximity cache-remove command to remove entries from the proximity lookup cache. The prefix length parameter allows you to remove multiple entries in a single operation. This Network Proximity command can be used only on a PDNS.
The syntax for this SuperUser configuration mode command is:
proximity cache-remove ip_address ip_prefix|all
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The proximity cache-remove command supports the following variables and option:
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For example:
# proximity cache-remove 150.45.6.10 /24Displaying Proximity Domain Name Server Configurations
The CSS CLI provides a comprehensive set of Network Proximity show commands that display proximity configurations. Refer to the following sections for information on using PDNS show commands:
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Displaying the Proximity Cache
Use the show proximity cache command to display the current state of the proximity lookup cache. This display provides information about the current cache configuration, entries present, number of hits, and so on. This command is available only on the PDNS.
The syntax for this global configuration command is:
show proximity cache {all|ip_address ip_prefix}
The show proximity cach command supports the following variables and option:
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For example:
(config)# show proximity cacheTable 5-13 describes the fields in the show proximity cache screen.
To display all information pertaining to the proximity cache, enter:
(config)# show proximity cache allTable 5-14 describes the fields in the show proximity cache all screen.
Displaying DNS-Record Statistics
Use the show dns-record statistics command to display statistics associated with the domain records configured locally and learned by the CSS from its peers. For details, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Displaying DNS-Record Statistics".
Displaying DNS-Record Keepalives
Use the show dns-record keepalive command to display information about keepalives associated with DNS records. For details, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Displaying DNS Record Information".
Displaying DNS Server Zones
Use the show zone command to display information about proximity zones communicating with a CSS Network Proximity service. For details, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Displaying DNS Server Zones". To display PDB-related zone information, see "Showing Proximity Zones" earlier in this chapter.
Displaying DNS-Record Proximity
Use the show dns-record proximity command to display dns-record proximity statistics.
The syntax for this global configuration mode command is:
# show dns-record proximity
For example:
(config)# show dns-record proximityTable 5-15 describes the fields in the show dns-record proximity output.
Displaying DNS Server Information
Use the show dns-server command to display DNS server configuration and database information. Although this command is not specifically a PDNS command, it is nonetheless useful for displaying DNS server information. For details on using the show dns-server command, refer to Chapter 1, Configuring the CSS Domain Name Service, in the section "Displaying DNS Server and Zone Information".
