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151

Appendix B

Error Messages

This appendix contains the following sections:

HTML messages sent to clients‚ on page 152 describes the HTML error messages that 
the Intel NetStructure Cache Appliance sends to browser clients (not to be confused 
with standard HTTP response codes)

Standard HTTP response messages‚ on page 154 describes the standard HTTP 
response codes that web servers send to browser clients

Summary of Contents for NetStructure 1520

Page 1: ...Intel NetStructure 1520 Cache Appliance Administrator s Guide...

Page 2: ...as to this document or the information contained herein with respect to i liability for infringement of any proprietary rights including without limitation intellectual property rights ii sufficiency...

Page 3: ...er 2 Getting Started 7 Starting the system for the first time 8 Accessing the Manager UI 12 Using Monitor and Configure mode 13 Using online help 15 Accessing the command line interface 15 Verifying t...

Page 4: ...uto configuration options 28 Setting throttling of network connections 28 Configuring load shedding 28 Enabling SNMP agents 29 Using the Protocols page 30 Configuring HTTP 30 Configuring NNTP 31 Confi...

Page 5: ...current network address settings 54 Using the main menu 54 Checking the status of the Server and Manager 55 Starting the appliance 55 Stopping the appliance 55 Viewing and maintaining versions of the...

Page 6: ...ions and Performance 113 Web proxy caching 114 A day in the life of a cache request 114 Ensuring cached object freshness 115 Revalidating objects 116 HTTP object freshness tests 116 Deciding whether t...

Page 7: ...ontrol 142 Obeying NNTP control messages 143 Client bandwidth throttling 143 Carrier class architecture 143 Performance 143 High availability 145 Node fault tolerance 147 Expansion capabilities 147 Ce...

Page 8: ...shots page 48 Changing network address configuration on the NIC 52 Changing speed and transmission mode 53 Changing the DNS address 53 Changing the gateway address 53 Configuring the time zone setting...

Page 9: ...Adding caching rules 79 Deleting cache rules 81 Viewing cache rules 82 Adding IP Allow rules 82 Deleting IP Allow rules 82 Viewing IP Allow rules 83 Adding Manager Allow rules 83 Deleting Manager Allo...

Page 10: ...ns 98 Configuring logging options 98 Viewing logging options 99 Viewing node statistics 99 Viewing protocol statistics 100 Viewing Cache statistics 104 Viewing host database statistics 105 Viewing DNS...

Page 11: ...er 1 contains an overview of the appliance and an overview of this guide Chapter 2 through Chapter 1 contain procedural information about starting monitoring and configuring the appliance Chapter 6 co...

Page 12: ...s the following conventions Convention Purpose italics Represent emphasis and introduce terms for example the management cluster bold Represents graphical user interface options and menu names for exa...

Page 13: ...he appliance can serve user requests for objects from its cache or the caches of neighboring appliances rather than have requests served from an origin server This relief results in improved network p...

Page 14: ...caching appliance s large fast local cache This reduces backbone congestion provides faster response and improves the quality of service The following design features make the Intel NetStructure Cache...

Page 15: ...icles and can accept news feeds for designated news groups Intel NetStructure Cache Appliance features The appliance provides a rich set of features to ensure high performance and superior stability a...

Page 16: ...support In a hierarchy of proxy servers the appliance can act either as a parent or child cache either to other Intel NetStructure Cache Appliances or to other caching products Web server acceleration...

Page 17: ...eference appendixes To find out about See Procedures how to get started Starting the system for the first time on page 8 how to use the Manager UI Accessing the Manager UI on page 12 how to monitor an...

Page 18: ......

Page 19: ...er contains the following sections Starting the system for the first time on page 8 Accessing the Manager UI on page 12 Accessing the command line interface on page 15 Verifying that caching works on...

Page 20: ...must be in place during operation of the appliance Once you have made the physical connections you can initially configure your appliance and start it up Initially configuring and starting your system...

Page 21: ...Configure Date and Time view View Settings 8 Use the arrow keys to select network and press the Enter key The following network setup fields appear Enter IP Address 192 168 1 10______________ Enter Ho...

Page 22: ...light Savings Time__ Enter Time HH MM SS __ __ __ Enter Date MM DD YYYY __ __ __ 14 Set your Daylight Savings Time options Then enter the time using a 24 hour format e g for 2 14 56 PM enter 14 14 56...

Page 23: ...in the window of the VT100 terminal emulator screen 20 After your system completes the boot procedure a console login prompt appears with fields for both a login and password At the prompt supply admi...

Page 24: ...ou change the default administrator ID and password You can change these values by using the Security page For information on how to use the Security page see Using the Security page on page 39 Note S...

Page 25: ...e Manager UI has two modes Monitor and Configure In Monitor mode view performance statistics and graphs To access Monitor mode click the top of the MONITOR tab In Configure mode view and modify the ap...

Page 26: ...nd clicking the node of your choice For information about how to use each of the performance screens see Accessing monitor pages on page 18 When you are in Configure mode you can access pages that cha...

Page 27: ...ks After starting the appliance you should verify that it is up and running To see if the appliance is processing HTTP requests do the following 1 From the Monitor tab in the Manager UI click the Prot...

Page 28: ...th telnet and Manager UI access as soon as possible after installing each node To change the password for the Manager UI see Using the Security page on page 39 To change the password for the telnet or...

Page 29: ...cture Cache Appliance This chapter contains the following sections Accessing monitor pages on page 18 Using the Dashboard page on page 18 Using the Node page on page 20 Using the Graphs page on page 2...

Page 30: ...rely on Java To use the Monitor pages or any other pages in the UI make sure your browser is set to enable Java and JavaScript Information displayed on the monitor mode pages fall into two categories...

Page 31: ...lowing about a node Resolving alarms Alarms alert you to problems or warn you of potential problems Alarm conditions themselves are built into the appliance you cannot change them If an alarm light is...

Page 32: ...ance For information on how to contact Intel Customer Service see the Intel NetStructure Cache Appliance Product Support booklet that came with your system After changing the selected node that name a...

Page 33: ...e Protocols page button Note Online help provides descriptions for each of the statistics in the Protocols page Using the Cache page The Cache page provides cache statistics for the selected node Cach...

Page 34: ...e Host Database page on page 44 Note Online help provides descriptions of each of the statistics in the Other page Using the MRTG page Multi Router Traffic Grapher MRTG is a graphing tool that enables...

Page 35: ...u on how to set these values in the Manager UI This chapter contains the following sections Accessing configure pages on page 24 Using the Server Basics page on page 24 Using the Protocols page on pag...

Page 36: ...ration for assistance For information on how to contact Intel Customer Service see the Intel NetStructure Cache Appliance Product Support booklet that came with your system 3 Click the CONFIGURE tab A...

Page 37: ...enter the cache cluster name Local Domain Expansion on off Enables or disables local domain expansion If you want the appliance to attempt to resolve unqualified hostnames by expanding to the local d...

Page 38: ...or real IP address bound to its interface card and would also serve many more virtual addresses Using virtual IP addressing for node failover You can set up your user base to use a DNS round robin po...

Page 39: ...e field enter the subinterface ID This is the number between 1 255 that the interface uses for the address 5 Click the Add button Note To reset the fields click the Reset button Handling multiple inte...

Page 40: ...nnections are queued until existing connections close Note This section is available only if transparency is disabled If you enable transparency you do not see this option See Configuring load sheddin...

Page 41: ...g table describes the options Option Description HTTP hit transaction time low watermark The lower limit for HTTP transaction time in milliseconds When the average hit transaction time reaches this va...

Page 42: ...e user does make another request the timeout period starts over The user can close the connection at any time Keep Alive Timeout Outbound Specifies how long the appliance should keep open the connecti...

Page 43: ...e should wait for fulfillment of a connection request to a Web server If the appliance does not establish a connection to a Web server before this timeout expires the appliance terminates the connecti...

Page 44: ...ine access control use the command line interface See Configuring NNTP access on page 69 for more information If you are using an authentication server you must enter its name and port see page 33 NNT...

Page 45: ...s that pass before the appliance polls parent NNTP servers for new news groups The parent group lists change slowly Consequently you do not need to check them frequently Use the command line interface...

Page 46: ...PASV PORT is the default FTP connection mode If PASV mode fails the appliance uses PORT mode to initiate the data connection and then the appliance accepts it PASV only Specifies that the appliance in...

Page 47: ...ctions in the Cache page Cache activation The following table describes the cache activation configuration options Option Description Enable HTTP caching Enables caching of objects retrieved through H...

Page 48: ...numbers of alternates due to cookies If the appliance is set to vary on cookies you might encounter this problem See Variable content on page 38 for more information Option Description Verify freshnes...

Page 49: ...serving fewer objects from the cache according to the following options never never force a freshness check with the origin server for IMS revalidation requests only force a freshness check for IMS If...

Page 50: ...that you limit the number of alternates cached See Storage on page 36 If the request is for images Images are rarely personalized If the request is for anything other than text or images Using documen...

Page 51: ...off Enables or disables authentication Leave authentication on to check the administrator ID and password whenever a user logs on to the Manager UI Administrator s ID Specifies the administrator logi...

Page 52: ...liance tries the next parent cache The appliance supports multiple parent caches and parent failover Use the command line interface to configure multiple parent caches and parent failover which gives...

Page 53: ...cription ICP Mode Enables or disables ICP mode Only Receive Queries Send Receive Queries Disabled ICP Port Specifies the port to use for ICP messages The default port is 3130 ICP Multicast enabled on...

Page 54: ...ddress to identify the host Otherwise the ICP configuration requires a hostname Type ICP host type Use one of the following options 1 specifies a parent cache 2 specifies a sibling cache 3 specifies t...

Page 55: ...specified in document route rewrite rules defined through the command line interface Reverse proxy only Sets the appliance to operate solely as a server accelerator If you select Yes the appliance do...

Page 56: ...rency is enabled you will see the following message The transparency option is installed Redirected users will be served transparently If transparency is not enabled you will see the following message...

Page 57: ...Specifies how long DNS entries can remain in the database before they are flagged as stale You can choose from the following 12 hours 24 hours 48 hours For example if this timeout is 24 hours and a us...

Page 58: ...entry is not yet 24 hours old But since the background timeout has expired the appliance will first serve the user s request and then refresh the entry in the background Invalid host timeout Specifie...

Page 59: ...onds and it can save you hours of correcting configuration mistakes Option Description Resolve attempt timeout Specifies how long the appliance must wait for the DNS server to respond with an IP addre...

Page 60: ...e diskette which does not have a bootable image Option Description Name New Snapshot Specifies a name for the snapshot Do not include the forward slash character in the name Take Snapshot Takes a snap...

Page 61: ...l NetStructure Cache Appliance This chapter contains the following sections Starting the command line interface on page 50 Navigating the command line interface on page 51 Using the setup menu on page...

Page 62: ...y address domain name time zone and date and time install Install or update the appliance software This task takes several minutes commit Save the appliance network configuration after installing the...

Page 63: ...r more information load Load a saved configuration from a floppy disk See Using the load menu on page 108 for more information logoff Logoff from the current login Navigating the command line interfac...

Page 64: ...netmask address on the primary network interface controller in the appliance Change the speed and transmission mode of the primary network interface controller Change the DNS address and domain name...

Page 65: ...DNS address and domain name You can change the DNS address and domain name used by the appliance Changing the DNS address 1 Select the setup menu and press Enter 2 Select dns and press Enter Doing so...

Page 66: ...and time settings You can configure the appliance s date and time Configuring the date and time settings 1 Select the setup menu and press Enter 2 Select time and press Enter Doing so displays time an...

Page 67: ...anager status 1 Select the main menu and press Enter 2 Select status and press Enter Doing so displays a window that indicates whether the Server and Manager are UP or DOWN Starting the appliance Star...

Page 68: ...Select view and press Enter Doing so displays a list of version numbers Installing a new version of the appliance software You can update the software on your cache appliance using FTP to download the...

Page 69: ...ssage describing the upgrade You will see a warning that an OS upgrade later requires you to swap the primary and secondary drives 5 Press Ctrl X to proceed or Escape to abort If you select Proceed th...

Page 70: ...upgrade message OS Application upgrade After you press Ctrl X to proceed the CLI displays the message Upgrading To The New OS Please Wait The server transfers the application image upgrade file tar gz...

Page 71: ...ng which version of the appliance software is currently running You can check which version of the appliance software is running on your machine Viewing the current version of the appliance 1 Select t...

Page 72: ...tem gives little or no warning to users connected to the machine before logging them off You should halt the appliance only as a last resort to problems Halting the system 1 Select the main menu and p...

Page 73: ...ngs 3 Be sure that y appear after the confirmation prompt and then press Enter 4 Press CTRL X to reset the settings and return to the previous screen Choosing to reset the settings causes the applianc...

Page 74: ...ess CTRL X to save your changes and return to the previous screen To enter a multicast group address select multicast address and press Enter Doing so displays the current multicast address and a fiel...

Page 75: ...ious screen To cancel the operation be sure n appears after the prompt and press Enter Or you can press ESC to exit the screen Configuring protocol options You can set HTTP NNTP and FTP configuration...

Page 76: ...se the proxy authorization header field applies only to the next outbound proxy that demanded authentication using the proxy authenticate field this feature is added so that you can force the traffic...

Page 77: ...n add delete and view NNTP server rules The appliance uses NNTP server rules to let you specify The parent NNTP servers from which you want the appliance to cache articles The news groups you want the...

Page 78: ...strictions should be placed later in the list Examples distrib pats The previous example does not include any distrib pats files but does include all others alt The previous example does not include a...

Page 79: ...llover The appliance actively pulls the overview database for the news groups but retrieves news articles on demand A pullover line must be preceded by a cache on demand line The appliance needs to be...

Page 80: ...or pullover group must be preceded by a cache on demand line as follows Deleting NNTP server rules 1 Select the config menu and press Enter 2 Select protocols and press Enter 3 Select nntp and press...

Page 81: ...lect nntp and press Enter 4 Select access and press Enter 5 Select add rules and press Enter 6 Enter an NNTP access rule and press Enter 7 Press CTRL X to save the rule and return to the previous scre...

Page 82: ...ur change and return to the previous screen Viewing NNTP access rules 1 Select the config menu and press Enter 2 Select protocols and press Enter 3 Select nntp and press Enter 4 Select access and pres...

Page 83: ...ter You can enter a maximum of two ports When entering more than one port separate them with blank space Also you must enter the complete list of ports even if one is already specified in the existing...

Page 84: ...URL requests and keep or strip header information When a URL request is allowed the appliance will cache and serve the requested document When a request is denied the client receives an access denied...

Page 85: ...ge such as 08 00 14 00 src_ip The IP address of the client prefix A prefix in the path part of a URL suffix A file suffix in the URL port A requested URL port method A request URL method one of the fo...

Page 86: ...RL X to save your changes and return to the previous screen Viewing filter rules 1 Select the config menu and press Enter 2 Select protocols and press Enter 3 Select filter and press Enter 4 Select vi...

Page 87: ...st of the current remap rules If no rules exist a message appears at the bottom of the screen indicating such 5 Use the arrow keys and position the cursor over the rule you want to delete and press En...

Page 88: ...nt to change Note You are not prompted for confirmation Make sure you want to complete the action before you select one of the following options and press Enter To enable HTTP caching select the first...

Page 89: ...e maximum size of the HTTP or FTP objects that you want the appliance to cache and press Enter 5 In the New Maximum number of alternates field type the maximum number of alternates that you want the a...

Page 90: ...n The Object Has Expired Or Has No Expiry Date The appliance revalidates objects with explicit expiration dates after they expire All other documents are revalidated before serving Always The applianc...

Page 91: ...ect arrives in the cache Enter the time in seconds and press Enter After pressing Enter press CTRL X to save your changes and return to the previous screen Internet Explorer options Versions of Micros...

Page 92: ...se more than one secondary specifier in a rule However you cannot repeat a secondary specifier primary destination value secondary specifier value action value Primary Destination Allowed Value dest_d...

Page 93: ...ress Enter Doing so displays a list of the current rules If no rules exits a message appears at the bottom of the screen indicating such 5 Use the arrow keys to position the cursor over the rule you w...

Page 94: ...ew IP Allow rules Adding IP Allow rules 1 Select the config menu and press Enter 2 Select security and press Enter 3 Select server and press Enter 4 Select add rules and press Enter 5 Enter an IP allo...

Page 95: ...anges of IP addresses that are allowed to access the Manager UI If you want to deny Manager UI access to specific IP addresses do not include them in a Manager Allow rule You can add delete and view M...

Page 96: ...Select the config menu and press Enter 2 Select security and press Enter 3 Select mgmt and press Enter 4 Select view rules and press Enter Doing so displays the file containing the Manager Allow rule...

Page 97: ...ach field host hostIP cache_type proxy_port icp_port MC_on MC_IP MC_TTL Field Description host The host name of the ICP peer The name localhost is reserved for the appliance host IP The IP address of...

Page 98: ...n the cursor over the rule you want to delete and press Enter 7 Press CTRL X to save your changes and return to the previous screen MC_IP The multicast IP address If MC_on is disabled appliance ignore...

Page 99: ...whether ICP multicast is enabled or disabled and the ICP query timeout by viewing the settings Viewing ICP settings 1 Select the config menu and press Enter 2 Select routing and press Enter 3 Select i...

Page 100: ...outing and press Enter 3 Select icp and press Enter 4 Select disable multicast and press Enter Setting the ICP port number You can set the ICP port number Setting the ICP port number 1 Select the conf...

Page 101: ...quests to bypass parent proxies You can enable and disable parent proxy caching as well as configure parent proxy caching rules Note For the parent proxy rules to take effect HTTP parent proxy service...

Page 102: ...alue action value Primary Destination Allowed Value dest_domain Requested domain name dest_host Requested host name dest_ip Requested IP address url_regex Regular expression to be found in a URL Secon...

Page 103: ...caching rules 1 Select the config menu and press Enter 2 Select routing and press Enter 3 Select parent and press Enter 4 Select rules and press Enter 5 Select delete rules and press Enter Doing so d...

Page 104: ...s Enter 2 Select routing and press Enter 3 Select wccp and press Enter 4 Select disable and press Enter Configuring WCCP options 1 Select the config menu and press Enter 2 Select routing and press Ent...

Page 105: ...return to the previous screen To delete all routers select delete routers and press Enter Viewing current WCCP options 1 Select the config menu and press Enter 2 Select routing and press Enter 3 Sele...

Page 106: ...f IP addresses For example use this solution to bypass clients that do not want to use caching Destination bypass Configures the appliance to bypass a particular destination IP address or range of IP...

Page 107: ...anges and return to the previous screen Viewing ARM bypass rules 1 Select the config menu and press Enter 2 Select arm and press Enter Rule Format source IP bypass bypass src src_IP Where src_IP can b...

Page 108: ...ss Enter 3 Select shedding and press Enter Doing so displays a field that has the current value for the maximum number of connections 4 Supply the maximum number of connections in the field and press...

Page 109: ...ow long DNS entries can remain in the database before they are flagged as entries to refresh in the background These entries are still fresh so they can be refreshed after they are served rather than...

Page 110: ...Select the config menu and press Enter 2 Select logging and press Enter 3 Select collation and press Enter Doing so displays current values in separate fields Following are default values Enter Collat...

Page 111: ...statistics include document hit rates the number of HTTP transactions per second and the number of open client and server connections Viewing node statistics 1 Select the monitor menu and press Enter...

Page 112: ...luster Transactions Per Second The number of HTTP transactions per second Statistic Continued Description Continued Statistics Description Hits Fresh The percentage of hits that are fresh and their av...

Page 113: ...ups The percentage of pre request hangups and their average transaction times Pre Connect Hangups The percentage of pre connect hangups and their average transaction times Other transactions Unclassif...

Page 114: ...rver Open Connections The number of currently open NNTP server connections Bytes Read The number of bytes read from parent NNTP servers since installation Bytes Written The number of NNTP bytes writte...

Page 115: ...nections Failures The number of PASV connection failures since installation PORT Connections Successes The number of successful PORT connections since installation PORT Connections Failures The number...

Page 116: ...an HTTP request that is sent to ICP to receive an ICP response This is a cumulative average value Queries Originating from ICP Peers Query Messages Received The number of ICP query messages received f...

Page 117: ...NTP HTTP and FTP Cache Writes Failed The number of cache write failures since installation NNTP HTTP and FTP Cache Updates Completed The number of cache HTTP updates completed since installation Cache...

Page 118: ...al number of DNS lookups queries to name servers since installation Successes The total number of DNS lookup successes since installation Average Lookup Time msec The average DNS lookup time Statistic...

Page 119: ...by visiting http docs sun com Entering expert mode 1 Select the expert menu and press Enter Doing so causes control to switch to the Unix operating system Note To return to the CLI enter exit at the...

Page 120: ...mote boot and halt operations to malfunction Using the load menu The load menu lets you copy a previously saved appliance configuration file from a floppy disk Loading a previously saved configuration...

Page 121: ...his chapter to help you find a solution If the information in this chapter doesn t solve your problem refer to the Intel NetStructure Caching Appliance Product Support booklet that came with your syst...

Page 122: ...e During a reboot operation the system maintains the state of the caching software For example if the caching software is running when the reboot operation is initiated they will still be running afte...

Page 123: ...on the Intel NetStructure Cache Appliance might need upgrading or might need to have a patch applied In this case visit Intel s ISP web site at http www intel com isp and go to the product page for yo...

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Page 125: ...d performance of the Intel NetStructure Cache Appliance This chapter covers the following topics Web proxy caching on page 114 Transparent proxy caching on page 120 Server acceleration on page 128 Und...

Page 126: ...nformation Transparent and explicit proxy caching The proxy supports both transparent proxy caching where the user s client software is unaware that it is communicating with a proxy and explicit proxy...

Page 127: ...nce revalidate stale HTTP objects How does the appliance test an HTTP object for freshness How does the appliance decide to serve an HTTP object How do you configure the appliance s HTTP freshness opt...

Page 128: ...bject along with a 111 Revalidation Failed warning HTTP object freshness tests Here s how the Intel NetStructure Cache Appliance determines an HTTP document s freshness Expires header test Some docume...

Page 129: ...freshness limits to specific HTTP or FTP objects From the command line interface you can set freshness limits for objects originating from particular domains or IP addresses objects with URL addresses...

Page 130: ...iguring HTTP freshness options You can configure the following freshness guidelines for the Intel NetStructure Cache Appliance How often to revalidate when to consider objects stale See Configuring HT...

Page 131: ...a server delivers content for different languages targets different browsers with different presentation styles or delivers variable content at different times of the day Different versions of the sam...

Page 132: ...of how the appliance serves requests transparently See Serving requests transparently on page 121 A discussion of interception strategies supported by the Intel NetWorking Cache Appliance See Intercep...

Page 133: ...y exempted from caching by configuring the ARM See Adaptive interception bypass on page 126 for more information Step 4 The appliance receives and begins processing the intercepted client requests as...

Page 134: ...s depending on the particular switch A layer 4 aware switch can sense downed hosts on the network and redirect traffic Single layer 4 aware switches that feed several appliances balance loads among th...

Page 135: ...way to the appliance The user then sees the response exactly as if it were sent directly from the origin server In addition to port 80 HTTP traffic WCCP 2 0 supports more protocols including NNTP port...

Page 136: ...de requests aimed at a particular range of IP addresses so that each node is responsible for caching content residing at particular IP addresses The appliance also supports cache affinity If a node fa...

Page 137: ...n the return path to the client so that the documents appear to have come straight from the origin server An appliance cluster with virtual IP failover adds reliability if one node fails another node...

Page 138: ...ot get access to the server A server limiting IP addresses is not infrequent Limitations occur because ISPs dynamically allocate client IP dial up addresses and use more secure cryptographic protocols...

Page 139: ...tells the appliance to bypass a particular source IP address or range of IP addresses For example you can use this rule to bypass clients that want to opt out of a caching solution Source bypass rule...

Page 140: ...the appliance has the desired object in cache it serves the document quickly If the document is not in cache the appliance requests the document from another backup Web server that has all the content...

Page 141: ...that origin server Interception occurs by setting up the DNS entry for the origin server the origin server s advertised host name to resolve to the appliance s IP address If the appliance is clustere...

Page 142: ..._books com would be Two types of rules exist map rules and reverse map rules Map rules specify the location of content that the appliance is accelerating they enable the appliance to translate a URL r...

Page 143: ...load For instance if a server is overloaded it might redirect browsers to a less loaded server Another reason might be when Web pages have moved to different locations When the appliance is configure...

Page 144: ...path portion of the target URL must match a prefix of the request URL If the appliance finds a match it translates the request URL into the replacement URL in the rule It sets the host and path of the...

Page 145: ...r Request Translated Request http www x com Widgets index html http server hoster com x Widgets index html http www x com cgi form submit sh arg true http server hoster com x cgi form submit sh arg tr...

Page 146: ...s that do not send the Host header The best solution is to direct the user to a page that explains the situation and advises a browser upgrade or provides a link directly to the origin server bypassin...

Page 147: ...the appliance chooses a specific parent to forward the request to the origin server The Intel NetStructure Cache Appliance can function as a member of the following cache hierarchies HTTP cache hiera...

Page 148: ...s parent caches Sibling caches exist at the same hierarchical level while parent caches exist one level up in the hierarchy A cache exchanges ICP messages only with specific ICP peers An ICP peer can...

Page 149: ...ion of the Configure Routing page see Setting ICP options on page 41 For information on how to configure ICP options using the command line interface see Configuring and maintaining ICP peers on page...

Page 150: ...Netscape Communicator or Microsoft Internet Explorer and access to a news server The appliance is a caching news server It can be configured to sit transparently between users and a parent or backing...

Page 151: ...can also tell the appliance to pull article overview lists from the parent news server periodically Caches and serves articles on demand The appliance can also accept news feeds like any news server C...

Page 152: ...d restored to their specified priority when they become available Several servers supplying different groups Several news servers can be configured with news servers supplying different disjoint group...

Page 153: ...Structure Cache Appliance sends user article postings to the parent news server You can specify the parent news server that receives postings for a particular group or set of groups from the command l...

Page 154: ...ll feed for some or all groups For all groups designated as feed the appliance does not connect to the parent news server and instead acts like a conventional news server In particular if a cache miss...

Page 155: ...h throttling You can limit the amount of bandwidth allotted to clients for downloading articles Clients that attempt to exceed the bandwidth limit will have each operation slowed to keep their bandwid...

Page 156: ...the same cache size Fast space reclamation A space reclamation algorithm ensures the appliance collects and removes stale data This garbage collection runs continuously and in real time RAM caching T...

Page 157: ...IP network packet engine called the Adaptive Redirection Module ARM This packet engine supports high speed interception of traffic for transparency supports automatic bypass of sites that do not funct...

Page 158: ...ppliance cluster The appliance handles virtual IP failover in the following ways By maintaining cluster communication Nodes automatically exchange statistics and configuration information through mult...

Page 159: ...this occurs the appliance marks that portion of disk as corrupt and continues to use the rest of the disk while avoiding the corrupt portion A total disk failure is one in which the hard drive become...

Page 160: ...he Manager UI is a Web based interface that you can access through a browser You can configure management access to the Manager UI through password authentication See Chapter 4 Configuring the Applian...

Page 161: ...All SNMP agents require you to configure the trap destination IP address before they can send traps This configuration varies among agent implementations It can also depend on the MIB Client ACL In a...

Page 162: ......

Page 163: ...ents on page 152 describes the HTML error messages that the Intel NetStructure Cache Appliance sends to browser clients not to be confused with standard HTTP response codes Standard HTTP response mess...

Page 164: ...d HTTP request for FTP Object 400 Bad HTTP request for FTP object Cache Read Error 500 Error reading from cache Please retry request Connection Timed Out 504 Server has not sent any data for too long...

Page 165: ...name is using an unsupported version of the HTTP protocol Invalid HTTP Request 400 Could not process this client request HTTP method request for URL Invalid HTTP Response 502 The host server name did...

Page 166: ...ing Not Available 406 Unable to provide the document URL in the format requested by your browser Tunnel Connection Failed 502 Could not connect to the server host name Unknown Error 502 The host host...

Page 167: ...400 Bad Request 401 Unauthorized retry 403 Forbidden 404 Not Found 405 Method Not Allowed 406 Not acceptable 408 Request Timeout 500 Internal server error 501 Not Implemented 502 Bad Gateway 504 Gatew...

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Page 169: ...when requested See also Object store Cache hierarchy Levels of caches that communicate with each other All cache hierarchies recognize the concepts of Parent cache and Child cache Cache hit An object...

Page 170: ...streamline conversion of host names to IP addresses Explicit proxy caching A configuration option where client software typically a browser must be specifically configured to send web requests to the...

Page 171: ...n query in the SNMP agent of a network device for example a router The Intel NetStructure Cache Appliance supports two MIBs MIB2 a well known standard MIB and the proprietary Intel NetStructure Cache...

Page 172: ...to cache objects Server acceleration See Reverse proxy SNMP Simple Network Management Protocol A set of standards used for communication with devices connected to a TCP IP network SNMP compliant devic...

Page 173: ...rotocol A protocol used by Cisco IOS based routers to redirect traffic during transparent proxy caching Web proxy server Forwards client requests to Origin servers The proxy server may deny requests a...

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Page 175: ...nagement only 141 Configuring HTTP 30 Configuring Protocols 30 Configuring SNMP agents 29 content fingerprinting 144 D dataflow core 143 disk failure tolerance 147 DNS resolver 144 F feed group 142 fr...

Page 176: ...in cache 81 proxy caching about 114 explicit and transparent 114 HTTP alternates 119 whether to cache 119 pull group 142 pullover group 141 push group 142 R RAM cache about 144 redirects 131 revalida...

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