|
|
The Cisco IOS software includes a Web browser from which you can issue Cisco IOS commands. This Cisco IOS feature is accessed from the router's home page and can be customized for your business environment. For example, you can view pages in different languages and save them in Flash memory for easy retrieval. You can also configure the Web Cache Control Protocol (WCCP) to handle Web traffic and increase the efficiency of your time spent on the Web.
For a complete description of the Cisco Web browser configuration commands in this chapter, refer to the "Cisco Web Browser Commands" chapter of the Configuration Fundamentals Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
Use of the Cisco Web browser is optional. To use and customize the Cisco Web browser, complete the tasks in the following sections:
You can issue most of the Cisco IOS commands using a Web browser. This Cisco IOS feature is accessed by using the Cisco Web browser interface, which is accessed from the router's home page. (All Cisco routers and access servers loaded with the latest version of Cisco IOS software have a home page, which is password protected.)
From the router's home page, you click on a hypertext link titled "Monitor the Router." This link takes you to a Web page that has a "Command" field. You can type commands in this field as if you were entering commands at a terminal connected to the router. The page also displays a list of commands. You can execute these commands by clicking on them, as if you were clicking on hypertext links.
To use the Cisco Web browser interface to issue commands, use the commands in the following sections:
The Web browser interface is automatically enabled when you use ClickStart to configure a Cisco 1003, Cisco 1004, or Cisco 1005 router. You must enable the Cisco Web browser interface on all other Cisco IOS routers. Once enabled, you will be able to issue Cisco IOS commands to your router using a Web browser.
If you have any other Cisco router, you must enable the Web browser interface by altering the routers' configuration. To do this, perform the tasks in the following list. The first task is required; the remaining are optional.
To enable a Cisco router to be configured from a browser using the Cisco Web browser interface, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
Enable a router to be reconfigured using the Cisco Web browser interface. |
Now that the Cisco Web browser interface is enabled, you can perform any of the optional tasks or proceed to configure a router using the Cisco Web browser interface.
By default, the Cisco Web browser interface uses port 80 on the router. To assign the Cisco Web browser interface to a different port, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
Assign a port number to be used by the Cisco Web browser interface. |
To control which hosts can access the HTTP server used by the Cisco Web browser interface, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
Control access to the HTTP server used by the Cisco Web browser interface. |
| Command | Purpose |
|---|---|
Specify how HTTP server users are authenticated. |
To use the Cisco Web browser interface, your computer must have a World Wide Web browser. The Cisco Web browser interface works with most browsers, including Netscape Navigator. Your Web browser must be able read and submit forms. The original versions of Mosaic might have problems using the Cisco Web browser interface, because they either cannot submit forms or have difficulty doing so.
The computer must be connected to the same network that the router or access server is on.
Cisco IOS software allows users with a default privilege level of 15 to access a predefined home page for a router or access server. If you have been assigned a privilege level other than 15, Cisco IOS Release 11.3 or later software allows you to issue Cisco IOS commands from a Web page where the commands defined for your specific user privilege level will be displayed.
To access the home page for your router or access server with a default privilege level of 15, perform the following steps:
Step 1 Enter the following command in the URL field of your Web browser and press return: http://router-name/. (For example, to access a Cisco router named cacophony with a default privilege level of 15, type http://cacophony/.)The browser then prompts you for the password.
Step 2 Enter the password.
The browser should display the home page for your router or access server.
The router's home page looks something like the Cisco 7200 home page shown in Figure 8.
Step 1 Enter the following command in the URL field of your Web browser and press return: http://router-name/level/level/mode/command. (For example, to request a user privilege level of 12 on a Cisco router named cacophony, type http://cacophony/level/12/exec).The browser then prompts you for the username and/or password.
Step 2 Depending on your authentication method, enter your username and/or password and press return. The Web browser should display a Web page specific to your user privilege level, mode, and the command you have requested.
Table 10 lists the URL arguments you must use when requesting a Web page.
| Argument | Description |
|---|---|
router-name | Name of the router being configured. |
level | The privilege level you are requesting. |
mode | The mode the command will be executed in, such as exec, configure, and interface. |
command | (Optional) The command you want to execute. If you specify a command, your browser will display a Web page showing the results of the requested command. If you do not specify a command in the URL, your browser will display a Web page listing all of the commands available for your privilege level. |
To issue commands using the Cisco Web browser interface, click the link "Monitor the router" in the first list of hypertext links on the home page. This displays the Web page shown in Figure 9.
To enter a command using hypertext links, scroll through the commands listed at the bottom of the screen and click the one you want to execute. If the link is a complete command, it is executed. If the command has more parameters, another list of command hypertext links is displayed. Scroll through this second list and click the one you want to execute.
If the command is a request for information, like a show command, the information is displayed in the Web browser window.
If the command requires a variable, a form in which you can enter the variable is displayed.
Entering the command in the command field is just like entering it at a terminal console. Enter the command using the syntax documented in the Cisco IOS command reference. If you are uncertain of the options available for a particular command, type a question mark (?).
For example, entering show ? in the command field displays the parameters for the show command. The Cisco Web browser interface displays the parameters as hypertext links. To select a parameter, you can either click on one of the links, or you can enter the parameter in the command field.
You can issue a command using the URL window for the Web browser.
For example, to execute a show configuration command on a router named example, you would enter the following in the URL window:
http://example/exec/show/configuration
The Web browser then displays the configuration for the "example" router. To save effort, modify the URL in the URL window in the browser control bar instead of retyping the entire URL.
The difference between entering a command in the command field and entering a command in the URL window is that in the URL window, command modes, keywords, and options should be separated by slashes, not spaces.
You can customize HTML pages to display Cisco IOS command output and Cisco IOS platform-specific variables (for example, a router host name or router address typically used in router setup pages) for a Web browser. You can display this information using HTML formatted Server Side Includes (SSIs) that you insert into your custom HTML pages. SSIs are a Cisco IOS software feature described in the following sections.
The Cisco IOS software supports two HTML SSI commands defined for customizing HTML pages: the SSI EXEC command and the SSI ECHO command. The HTML format of the SSI EXEC command is <!--#exec cmd="xxx"-->, and the HTML format of the SSI ECHO command is <!--#echo var="yyy"-->. (See the section "Customize HTML Pages Using SSIs" later in this chapter for a description of how to use these commands).
In addition to the two SSI commands, the Cisco IOS software supports several SSI variables defined for customizing HTML pages. SSI variables are used with the SSI ECHO command. There is one SSI variable defined for all Cisco IOS platforms (SERVER_NAME) and other SSI variables specifically defined for ISDN, Frame Relay, and asynchronous serial platforms. The format and a description of all the available SSI variables are provided in Table 5. (See the section "Customize HTML Pages Using SSIs" later in this chapter for a description of how to use these SSI variables with the SSI ECHO command).
The SSI EXEC command is supported on all platforms. The SSI ECHO command, used with SSI variables, is supported on all platforms listed in Table 11.
| HTML Format of SSI Variable | Description of Variable Displayed on Browser Page | Cisco IOS Platform(s) This SSI Is Supported On |
|---|---|---|
SERVER_NAME | Host name of the HTTP server. | All Cisco IOS platforms |
EZSETUP_PASSWORD | Enable password (currently left blank). | Cisco 1000 series |
EZSETUP_PASSWORD_VERIFY | Repeat of the enable password to verify accuracy (currently left blank). | Cisco 1000 series |
EZSETUP_ETHERNET0_ADDRESS | IP address of the Ethernet 0 interface. | Cisco 1000 series |
EZSETUP_ETHERNET0_MASK | IP mask of the Ethernet 0 interface. | Cisco 1000 series |
EZSETUP_DNS_ADDRESS | DNS address used by the router. | Cisco 1000 series |
EZSETUP_STANDARD_DEBUG_Y | Standard debug variable. Returns CHECKED if set to TRUE; otherwise, it is blank. | Cisco 1000 series |
EZSETUP_STANDARD_DEBUG_N | Standard debug variable. Returns CHECKED if set to FALSE; otherwise, it is blank. | Cisco 1000 series |
EZSETUP_ISDN_SWITCHTYPE | ISDN Switch type. | Cisco 1003 and Cisco 1004 |
EZSETUP_ISDN_REMOTE_NAME | Name of remote ISDN system. | Cisco 1003 and Cisco 1004 |
EZSETUP_ISDN_REMOTE_NUMBER | Phone number of remote ISDN system. | Cisco 1003 and Cisco 1004 |
EZSETUP_ISDN_CHAP_PASSWORD | CHAP password of remote ISDN system. | Cisco 1003 and Cisco 1004 |
EZSETUP_ISDN_SPID1 | ISDN SPID 1. | Cisco 1003 and Cisco 1004 |
EZSETUP_ISDN_SPID2 | ISDN SPID 2. | Cisco 1003 and Cisco 1004 |
EZSETUP_ISDN_SPEED_56 | Speed of ISDN interface. Returns CHECKED if set to 56k; otherwise, it is blank. | Cisco 1003 and Cisco 1004 |
EZSETUP_ISDN_SPEED_64 | Speed of ISDN interface. Returns CHECKED if set to 64k; otherwise, it is blank. | Cisco 1003 and Cisco 1004 |
EZSETUP_FR_ADDRESS | Frame-Relay IP address. | Cisco 1005 |
EZSETUP_FR_MASK | Frame-Relay IP mask. | Cisco 1005 |
EZSETUP_FR_DLCI | Frame-Relay DLCI. | Cisco 1005 |
EZSETUP_ASYNC_REMOTE_NAME | Name of remote system. | Cisco 1005 |
EZSETUP_ASYNC_REMOTE_NUMBER | Phone number of remote system. | Cisco 1005 |
EZSETUP_ASYNC_CHAP_PASSWORD | CHAP password for remote system. | Cisco 1005 |
EZSETUP_ASYNC_LINE_PASSWORD | Async line password. | Cisco 1005 |
EZSETUP_ASYNC_MODEM_SPEED | Speed of async modem (either 14.4k or 28.8k). | Cisco 1005 |
EZSETUP_ASYNC_MODEM_SPEED_144K | Returns CHECKED if async modem speed is 14.4k; otherwise it is blank. | Cisco 1005 |
EZSETUP_ASYNC_MODEM_SPEED_288K | Returns CHECKED if async modem speed is 28.8k; otherwise it is blank. | Cisco 1005 |
Once you have designed a set of HTML pages that include SSIs, you can copy these pages to a Cisco IOS platform's Flash memory. (See the section "Copy HTML Pages to Flash Memory" for instructions on storing HTML pages in Flash memory later in this section.) When you retrieve these pages from Flash memory and display them using a Web browser, any SSI command that was designed into these pages will either display Cisco IOS command output or display a current variable or identifier defined in Table 9. For example, the SSI ECHO command with the variable SERVER_NAME will display the current host name of the HTTP server you are using, and the SSI ECHO command with the variable EZSETUP_ISDN_SWITCHTYPE will display the current ISDN switch type you are using.
To customize your HTML pages and view them for the user interface, perform the tasks in the following sections:
When you are customizing an HTML page for a Web browser, type <!--#exec cmd="xxx"--> in your HTML file where you want Cisco IOS command output to appear on the browser page. Replace xxx with a Cisco IOS command that can be executed in the router's EXEC mode. (See the "SSI EXEC Command Example" section later in this chapter.)
When you are customizing an HTML page for a Web browser, type <!--#echo var="yyy"--> in your HTML file where you want a value or identifier associated with a particular Cisco IOS platform (for example, an ISDN or Frame Relay platform) to appear on the browser page. Replace yyy with an SSI variable described in Table 9. (See the "SSI ECHO Command Example" section later in this chapter.)
| Command | Purpose |
|---|---|
Enable the Cisco Web browser interface. |
Refer to the section "Configure the Cisco Web Browser Interface" earlier in this chapter for further information on configuring the Cisco Web browser interface.
Once the Cisco Web browser interface is enabled, you can retrieve your HTML page from Flash memory and view it on the Cisco Web browser by typing the URL http://router/flash/filename in the URL window. Replace router with the host name or IP address of the current Cisco IOS platform you are using, and replace filename with the name of the file you created with ".shtml" appended. For example, http://myrouter/flash/ssi_file.shtml.
Your Cisco IOS platform will automatically display 8-bit and multibyte character sets and print the ESC character as a single character instead of as the caret and bracket symbols (^[) when the Cisco Web browser interface is enabled with the ip http server command.
If you are Telneting to a Cisco IOS platform, use the following command in line configuration mode to display 8-bit and multibyte international character sets and print the ESC character as a single character instead of "^[":
| Command | Purpose |
|---|---|
Configure a router to display 8-bit and multibyte international character sets and print the ESC character as a single character instead of "^[" when Telneting to a Cisco IOS platform. |
If you are Telneting to a Cisco IOS platform, use the following command in EXEC mode to display 8-bit and multibyte international characters sets and print the ESC character as a single character instead of "^[" for the current Telnet session:
| Command | Purpose |
|---|---|
Configure a router to display 8-bit and multibyte international character sets and print the ESC character as a single character instead of "^[" when Telneting to a Cisco IOS platform for the current session. |
The Web Cache Control Protocol (WCCP) feature allows you to use a Cisco Cache Engine to handle Web traffic, thus reducing transmission costs and downloading time. This traffic includes user requests to view pages and graphics on World Wide Web servers, whether internal or external to your network, and the replies to those requests. Figure 10 shows a sample WCCP network configuration.
WCCP transparently redirects HTTP requests from the intended server to a Cisco Cache Engine. End users do not know that the page came from the cache engine rather than the originally requested Web server.
The Using Cisco Cache Engine publication contains detailed information about the Cisco Cache Engine and discusses alternative network configurations.
Web caches reduce transmissions costs and the amount of time required to download Web files. If a client requests a Web page that is already cached, the request and data only have to travel between the Cisco Cache Engine and the client. Without a Web cache, the request and reply must travel over the Internet or wide-area network. Cached pages can be loaded faster than non-cached pages and do not have to be transmitted from the Internet to your network.
Cisco IOS support of WCCP provides a transparent Web cache solution. Users can benefit from Web proxy caches without having to configure clients to contact a specific proxy server in order to access Web resources. Many Web proxy caches require clients to access Web resources through a specific proxy Web server rather than using the originally requested Web server URL. With WCCP, the clients send Web requests to the desired Web server URL. Cisco IOS routers intelligently intercept HTTP requests and transparently redirect them to a Cisco Cache Engine.
When a Web Cache Control Protocol-enabled router receives an IP packet, the router determines if the packet is a request that should be directed to a Cisco Cache Engine. The router looks for TCP as the protocol field in the IP header and for 80 as the destination port in the TCP header. If the packet meets these criteria, it is redirected to a Cisco Cache Engine.
Through communication with the Cisco Cache Engines, the routers running WCCP are aware of available cache engines.
WCCP is supported on the following platforms:
To use the Web Cache Control Protocol, IP must be configured on the interface connected to the Internet and the interface connected to the Cisco Cache Engine.
The interface connected to the Cisco Cache Engine must be an Ethernet or Fast Ethernet interface.
To configure the Web Cache Control Protocol on the router, you must use the following tasks. The first task is required, while the rest are optional.
To enable an interface to redirect Web traffic to the Cisco Cache Engine using the Web Cache Control Protocol, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Enable the router to use the Web Cache Control Protocol. | |||
| ip wccp redirect-list {number | name} | (Optional) Specify the redirect access list. Only packets that match this access list are redirected. If you do not configure this command, all Web-based packets are redirected. | ||
| interface interface | Enter interface configuration mode. | ||
| Configure the interface connected to the Internet to redirect Web traffic to the Cisco Cache Engine. | |||
| (Optional) If the client and a Cisco Cache Engine are located on the same network, configure the router to use the fast switching path on the interface. | |||
| end | Exit configuration mode. | ||
| copy running-config startup-config | Save the configuration. |
To monitor the Web Cache Control Protocol, use any of the following commands in EXEC mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Display global Web Cache Control Protocol statistics. | |||
| Display information about all known Cisco Cache Engines. | |||
| Show whether Web cache redirecting is enabled on an interface. |
The show ip wccp and show ip wccp web-caches commands display a count of the number of packets redirected. Use the clear ip wccp EXEC command to clear this counter.
To use WCCP, the Cisco Cache Engine must be properly configured. Refer to the Using the Cisco Cache Engine publication for details on configuring the Cisco Cache Engine. Keep these important points in mind:
This section provides the following configuration examples:
The following is an example of the HTML SSI EXEC command used to display the Cisco IOS show users EXEC command output:
Contents of the HTML file in Flash memory:
<HTML> <HEAD> <TITLE> SSI EXEC Command Example</TITLE> </HEAD> <BODY> This is an example of the SSI EXEC command <HR> <PRE> <!--#exec cmd="show users"--> </PRE> <HR> </BODY> </HTML>
Contents that the Web browser receives when the HTML file is retrieved from Flash memory:
<HTML> <HEAD> <TITLE> SSI EXEC Command Example</TITLE> </HEAD> <BODY> This is an example of the SSI EXEC command <HR> <PRE> Line User Host(s) Idle Location 0 con 0 idle 12 2 vty 0 idle 0 router.cisco.com </PRE> <HR> </BODY> </HTML>
Contents of the HTML file in Flash memory:
<HTML> <HEAD> <TITLE>SSI Echo Command Example</TITLE> </HEAD> <BODY> This is an example of the SSI echo command <HR> <!--#echo var="SERVER_NAME"--> <HR> </BODY> </HTML>
Contents that the Web browser receives when the HTML file is retrieved from Flash memory:
<HTML> <HEAD> <TITLE>SSI Echo Command Example</TITLE> </HEAD> <BODY> This is an example of the SSI echo command <HR> rain <HR> </BODY> </HTML>
The following example configures a router to support the Web Cache Control Protocol and to redirect Web-related packets from Ethernet interface 0 to the Cisco Cache Engine:
Router# configure terminal Router(config)# ip wccp enable Router(config)# interface Ethernet 0 Router(config-if)# ip web-cache redirect Router(config-if)# end Router# %SYS-5-CONFIG_I: Configured from console by console. Router# copy running-config startup-config
After the router has been configured, use the show ip wccp web-cache command to verify that Web Cache Control Protocol is enabled and aware of Cisco Cache Engines. In this example, the show ip wccp web-cache command is entered immediately after the router has been configured. After a few seconds, the cache engine becomes usable, as seen in the second output.
Router# show ip wccp web-cache WCCP Web-Cache information: IP Address:192.168.51.102 Protocol Version:0.3 State:NOT Usable Initial Hash Info:FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF Assigned Hash Info:00000000000000000000000000000000 00000000000000000000000000000000 Hash Allotment: 0 (0.00%) Packets Redirected: 0 Connect Time: 00:00:06 Router# show ip wccp web-cache WCCP Web-Cache information: IP Address192.168.51.102 Protocol Version:0.3 State:Usable Initial Hash Info:FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF Assigned Hash Info:FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF Hash Allotment:256 (100.00%) Packets Redirected:0 Connect Time:00:00:31
Posted: Wed Apr 28 10:10:03 PDT 1999
Copyright 1989-1999©Cisco Systems Inc.