|
|
This chapter describes tasks that can be performed as part of the configuration process, but are not necessarily needed for you to complete your system configuration. These tasks affect overall system operation. The tasks are as follows:
You can boot your router in three ways:
You can download new versions of the system image over the network. This process is called netbooting.
Netbooting works as follows: when you power up your Cisco router product for the first time, the router system software checks the software configuration register for default boot instructions or the nonvolatile memory for special netbooting instructions.
If the system finds netbooting instructions, it determines its interface address and then runs a special process to load the new software into memory using the Trivial File Transfer Protocol (TFTP).
Use the boot system global configuration command to netboot. The keyword system indicates that the filename and host address for booting operating software over the network are in the nonvolatile memory.
boot system testme5.tester 131 108.13.111
By default, the router uses an Internet address of all ones (255.255.255.255) to broadcast TFTP Read Request message. However, many hosts use an old style of broadcast address consisting of all zeros. You can change the operation of the router to accommodate hosts using the old style of broadcast address by using the ip broadcast-address command described in the "Routing IP" chapter of the Router Products Configuration and Reference publication.
Specifying netbooting with the boot system global configuration command uses the nonvolatile memory option, which enables you to provide more detailed instructions for software downloading. You can use the boot system configuration command to specify both the boot filename and the IP address of the server host. You must still set the bottom four bits of the configuration register to a netbooting value. This means that if you have only bit 0 set, the system runs the default ROM software and netbooting is not permitted. For more information about the configuration register, see "Configuration Register Settings" later in this chapter.
With a CSC-MC+ Flash memory card and either a CSC-MCI or
CSC-ENVM controller and appropriate cables, system software images can be written to Flash memory for booting. The Flash memory card is available for the AGS+, AGS, MGS, and CGS chassis. Flash EPROMs are available for the Cisco 3000, Cisco 4000, or as an upgrade for the
IGS/TR. Flash SIMMs are available for the Cisco 3000. Before you boot from Flash, you should configure your Flash memory. See "Copying TFTP Image to Flash Memories" later in this chapter for more
information about copying into the current Flash configuration.
You can automatically boot from the Flash memory card using the boot system flash system configuration command. You can also manually boot from the ROM monitor using the b flash command.
You can automatically boot the system from Flash memory using the boot system flash system configuration command. However, to use this command, one of the following must be true:
boot system configuration commands regardless of argument. Specifying the keyword flash or argument filename with the no boot system command disables only the command specified by these arguments.
The boot system flash command boots the first valid file in Flash memory. The boot system flash filename boots the file specified by this filename.
Configure the system to automatically boot from the desired file in Flash memory using the configure terminal command and the boot system flash filename system configuration command.
Write the configuration to nonvolatile memory with the write memory command. Following this, boot the system with the reload command.
Use the b flash command at the ROM monitor level to manually boot the system, as in the following example. Check the appropriate hardware manual for the correct jumper or configuration register setting.
>b flash
F3: 1578668+35572+156084 at 0x1000
RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
{ROM Monitor copyrights}
Refer to the "Configuring the System" chapter of the Router Products Configuration and Reference, for a description of the Flash commands. Refer to the appropriate hardware installation and maintenance publication for hardware installation instructions for Flash memory.
When netbooting with or without Flash memory you can specify the use of the ROM system image even though other boot instructions exist in the configuration. You can do this using the boot system rom command so that the ROM software is used as a backup. You can also set the configuration register to override the configuration file. See "Configuration Register Settings" later in this chapter.
The configuration register is a 16-bit register. For the IGS/TR, Cisco 3000 and Cisco 4000, the configuration register is a software configuration register that is written into the nonvolatile memory. However, any changes made to this register only take effect when the server restarts; that is when you switch the power off and on or when you issue a reload command from the console. For other systems, the configuration register is on the processor card or dip switches at the back of the system.
The Table 1-1 shows the software register value in hexadecimal, processor configuration register bit position in decimal, and the corresponding meaning of each bit in the configuration register. The software register value only applies to IGS/TR with Flash upgrade, Cisco 3000, and Cisco 4000.
| Software
Register Hex Value | Hardware Bit | Meaning |
|---|---|---|
| 0x0 | 0 | Boot from System Bootstrap |
| 0x1-0xF | 1-3 | Name of file for netbooting |
| 0x10, 0x20 | 4-5 | System dependent1 |
| 0x40 | 6 | Ignore NVRAM configuration |
| 0x80 | 7 | Boot default ROM software if network boot fails |
| 0x100 | 8 | Break disabled |
| 0x200 | 9 | System dependent1 |
| 0x400 | 10 | IP broadcasts with all zeros |
| 0x800, 0x1000 | 11-12 | System dependent1 |
| 0x2000 | 13 | Boot default ROM software if network boot fails |
| 0x4000 | 14 | IP broadcasts do not have net numbers |
| 0x8000 | 15 | Run diagnostic tests and ignore NVRAM contents |
Table 1-2 shows the binary values of the boot field (bits 0 through 3) and the corresponding default boot filename. The default filename is derived by interpreting the binary bit combination as an octal number. The value xxx represent the processor type, for example, 4000, igs, or csc3 are valid processor type values.
| Boot field Bits 0-3 | Default Boot Filename |
|---|---|
| 0000 | bootstrap |
| 0001 | ROM software |
| 0010 | cisco2-xxx |
| 0011 | cisco3-xxx |
| 0100 | cisco4-xxx |
| 0101 | cisco5-xxx |
| 0110 | cisco6-xxx |
| 0111 | cisco7-xxx |
| 1000 | cisco10-xxx |
| 1001 | cisco11-xxx |
| 1010 | cisco12-xxx |
| 1011 | cisco13-xxx |
| 1100 | cisco14-xxx |
| 1101 | cisco15-xxx |
| 1110 | cisco16-xxx |
| 1111 | cisco17-xxx |
The following rules apply when the router system software reads the configuration register. These rules are true whether the system has a processor configuration register or a software configuration register.
The default configuration register setting for any system with Flash is 0x101. Please refer to the appropriate hardware installation and maintenance publication for information on the configuration register settings for your system.
The streamlined setup command facility gives you an opportunity to continue to boot your system even though there may be problems with the configuration file you are attempting to netboot an image.
The router enters the streamlined setup command facility under the following circumstances:
The router enters the streamlined setup command facility if in addition to any of the above listed circumstances, the following is true:
If one of the listed items applies to your router, you will see the following screen:
--- System Configuration Dialog ---
Refer to the 'Getting Started' Guide for additional help.
Default settings are in square brackets '[]'.
Configuring interface IP parameters for netbooting:
Configuring interface Ethernet0:
Is this interface in use? [yes]:
IP address for this interface: 131.108.169.23
Number of bits in subnet field [0]: 8
Class B network is 131.108.0.0, 8 subnet bits; mask is
255.255.255.0
Configuring interface Ethernet1:
Is this interface in use? [yes]:
IP address for this interface: 131.108.163.23
Number of bits in subnet field [8]:
Class B network is 131.108.0.0, 8 subnet bits; mask is
255.255.255.0
"Configuring interface IP parameters for netbooting" only appears if you are netbooting and your configuration has insufficient IP information.
You will be asked to provide an IP address and subnet mask bits. You can enter the subnet mask bits as a decimal value such as 8.
The configuration information you provide at this screen is temporary and is only to allow you to proceed with booting your system. When you reload the system, your original configuration is left intact.
If you used the setup command facility and answered yes to the final prompt in the System Configuration Dialog, the configuration was saved in nonvolatile memory. The final prompt is as follows:
Use this configuration? [yes/no]:
If you choose not to create your configuration file this way, there are several options you may now choose from to create the configuration file that will be used for your system. To make your choice, note that the network server holds configuration information in two places--in running memory and in nonvolatile memory. Configuration information in running memory is temporary and will not be stored if power is shut off. Configuration information in nonvolatile memory is always available.
You can create a configuration file in one of the following ways:
Before deciding which configuration you want to use, compare configurations.You can display information stored in nonvolatile memory using the EXEC command show configuration. You can use the write terminal command to display the configuration running in memory.
If you decide to store a configuration file other than the one currently in nonvolatile memory, use the EXEC command write erase to clear the contents of nonvolatile memory first.
In addition to storing the configuration file in nonvolatile memory, you can store it on a server host on the network. The file can be stored using the write network command. (Storing on a remote host allows you to use an editor on the host to edit and create the configuration file.)
Enter the EXEC command configure at the privileged-level EXEC prompt to enter configuration mode. Once you are in configuration mode, issue configuration commands from the console terminal.
The router responds with the following prompt asking you to specify the terminal, a file, or nonvolatile memory as the source of configuration commands.
Configuring from terminal, memory, or network [terminal]?
To begin configuration at the console terminal, type terminal at the prompt or press Return (since terminal is the default) to start command collection. During command collection, the network server accepts one configuration command per line. You can enter as many configuration subcommands as you want.
Enter Ctrl-Z when you finish entering configuration commands. This returns you to the EXEC, where you can test your configuration or write the configuration commands to memory.
At periodic intervals, you will want to write the configuration information into nonvolatile memory or to a configuration file stored on a remote host. This will make checking, adding information to, and booting the configuration file an easier task. The procedures for writing information to nonvolatile memory are described next.
After you enter the desired configuration information at the console terminal, use the privileged EXEC command write memory to make a copy of the configuration information in the nonvolatile memory. Nonvolatile memory stores the current configuration information in text format as configuration commands, recording only nondefault settings. The memory is checksummed to guard against corrupted data.
As part of its startup sequence, the router startup software always checks for configuration information in the nonvolatile memory. If the nonvolatile memory holds valid configuration commands, the router executes the commands automatically at startup.
To display the configuration information stored in the nonvolatile memory, enter the show configuration EXEC command at the privileged-mode EXEC prompt.
To reexecute the configuration commands stored in nonvolatile memory, enter the EXEC command configure at the privileged-level EXEC prompt and enter configuration mode.
The network server responds with the following asking you to specify the terminal, a file, or nonvolatile memory as the source of configuration commands.
Configuring from terminal, memory, or network [terminal]?
To re-execute the configuration commands stored in nonvolatile memory, enter memory at the configure mode prompt.
To retrieve and/or add to the configuration information stored in a file on one of your network servers, enter the EXEC command configure at the privileged-level EXEC prompt and enter configuration mode.
The network server responds with the following prompt asking you to specify the terminal, a file, or nonvolatile memory as the source of configuration commands.
Configuring from terminal, memory, or network [terminal]?
Enter network at this prompt to retrieve and/or add to the configuration information stored on a host file. The system will ask you to select a host or network configuration file, for the address of the host, and for a filename. The following example illustrates this process.
Host or network configuration file [host]? IP address of remote host [255.255.255.255]?131.108.2.155Name of configuration file [tokyo-confg]? Configure using tokyo-confg from 131.108.2.155? [confirm]yBooting tokyo-confg from 131.108.2.155:!! [OK - 874/16000 bytes]
The network server can be configured to automatically load additional configuration information from a network host. You might want to keep an up-to-date version of configuration information on another host, where you can change it as necessary, and use the nonvolatile memory as a bootstrap or backup mechanism. You can instruct the network server to load configuration information over the network by entering the service config subcommand and then writing the information to nonvolatile memory using the write memory command. Loading configuration information over the network is the default if nonvolatile memory is not installed. The service configuration subcommand is described in the section "Tailoring Use of Network Services" in the "Configuring the System" chapter of the Router Products Configuration and Reference publication.
After loading configuration information from the nonvolatile memory, the network server will attempt to load two configuration files from remote hosts. The first is the network configuration file, which contains commands that apply to all network servers and communication servers on a network. The second is the host configuration file, which contains commands that apply to one network server in particular.
To store configuration information on a remote host, enter the privileged EXEC command write network. This command sends a copy of the current configuration information to a remote host. The command will prompt you for the destination host's address and a filename, as the following example illustrates.
Tokyo#write networkRemote host [131.108.2.155]? Name of configuration file to write [tokyo-confg]? Write file tokyo-confg on host 131.108.2.155? [confirm]yWriting tokyo-confg.. [OK]
The network server uses the Trivial File Transfer Protocol (TFTP) to load and save system images and configuration files.
The TFTP session can sometimes fail. To help determine why a TFTP session failed, TFTP generates a "E" character if it receives an erroneous packet, and an "O" if it receives an out-of-sequence packet. A period (.) indicates a timeout. The transfer session might still succeed even if TFTP generates these characters, but the output is useful for diagnosing the transfer failure.
This section is divided as follows:
The default name of the network configuration file is network-confg. The default name for the host configuration file is taken from the host name. The host name can be specified by the hostname configuration subcommand or can be derived from the Domain Name System (DNS); see the section "Setting the Host Name" in the "Configuring the System" chapter of the Router Products Configuration and Reference publication for more information. To form the host configuration filename, the network server converts the host name to lowercase, stripped of any DNS information, and appends "-confg." If no host name information is available, the default host configuration filename is router-confg. Other names for these configuration files can be set using the boot command, which is described in the section "Setting Configuration File Specifications" in the "Configuring the System" chapter of the Router Products Configuration and Reference publication.
The default host configuration filename has changed in Software Release 9.0 to router-confg, from the earlier releases' use of gateway-confg.
service config
no service config
To enable the loading of network configuration files at router reboot time, use the service config command. The no version of this command (the default) disables the loading of these files.
If the network server fails to load a configuration file during start up, it tries again every ten minutes (default setting) until a host provides the requested files. With each failed attempt, the network server displays a message on the console terminal.
If the network server is unable to load the file named network-confg, it displays the following message.
Booting network-confg... [timed out]
As configured at the factory, the operating system software executes instructions in the onboard EPROM. You need not change the system EPROMs with each software update. Instead, you can download the latest software over the network.
If the system finds netbooting instructions, it determines its interface address and then runs a special process to load the new software into memory using TFTP.
You can specify boot loading in two ways. The first way involves setting the low four bits of the configuration register. If no bits are set, you must manually boot the system using the System Bootstrap program.
The second way to specify netbooting uses the nonvolatile memory option, which enables you to provide more detailed instructions for software downloading. See "Booting the Router" earlier in this chapter for details.
Netbooting over X.25 and Frame Relay have special configuration considerations; refer to the "Configuring Packet-Switched Software" chapter of the Router Products Configuration and Reference for these special netbooting considerations.
The copy tftp flash command copies a TFTP image into the current Flash configuration:
copy tftp flash
If the image fits into the current Flash configuration, it prompts you for the IP address of the TFTP server and the TFTP filename.
You are given an option to erase existing Flash memory before writing onto it. The system then clears and initializes each Flash memory. A pound sign (#) prompt is displayed for each cleared and initialized device (16 total). The entire copying process takes several minutes and will differ from network to network.
The following example shows sample output of copying a system image, which is named gsxx, into the current Flash configuration.
Router#copy tftp flashIP address or name of remote host [255.255.255.255]? server1Name of file to copy ? gsxxCopy gsxx from 150.136.128.191 into flash memory? [confirm]Erasure is needed before flash may be written.Erase flash before writing? [confirm]Clearing and initializing flash memory (please wait)####...Loading from 150.136.128.191: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! [OK - 1648952/4194176 bytes]Verifying via checksum...VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVFlash verification successful.Length = 1648952,checksum = 0x00C2
The series of pound signs (#) indicate each Flash device is being cleared and initialized; one per device (16 total). The last line in the sample configuration indicates that the copy is successful. During the actual copy process, the yellow LED on the CSC-MC+ will be lighted.
The exclamation points indicate the copy process.
The series of Vs in the above sample output indicate that a checksum verification of the Flash is occurring as it is loaded into memory for boot. It is verified only through data compare during programming of the Flash.
If the TFTP image is too large, the following failure message appears:
buffer overflow - xxxx/xxxx
The value xxxx/xxxx is the number of bytes read in/number of bytes available.
Use the output of show flash all to obtain the image name. See "Verifying Installation and Displaying Flash ROM Statistics" in the "Configuring the System" chapter of the Router Products Configuration and Reference publication for more information about this EXEC command.
Once you have configured Flash memory, you are now ready to boot from Flash. You can automatically boot from the Flash memory card using the boot system flash system configuration command. See "Automatically Booting from Flash Memories" earlier in this chapter. for more information about booting from flash. You can also manually boot from the ROM monitor using the b flash command. See "Manually Booting from Flash Memories" earlier in this chapter for more information. about booting from Flash.
You can copy an image back to a TFTP server using the copy flash tftp command. This copy of the system image can serve as a back-up copy and may also be used to verify that the copy in Flash is the same as on the original file on disk.
The following example illustrates how to use this command:
Router# copy flash tftp IP address of remote host [255.255.255.255]? 101.2.13.110 filename to write on tftp host? gsxx writing gsxx !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! successful tftp write. Router#
You may want to configure the system with the no boot system flash command in order to revert to booting from ROM. See "Storing and Booting the System Image in Flash Memory" in the "Configuring the System" chapter of the Router Products Configuration and Reference publication.
Use the following EXEC command to halt and restart the router:
reloadIf the bit 0 on the configuration register is set, the router will automatically return the System Bootstrap prompt. Bit 0 is set if the rightmost pin on your processor has a jumper in it or the software configuration register has bit 0 set to 1. These settings are the default. If this bits is not set, you can manually boot the system using the System Bootstrap program by issuing the boot command or try to netboot over the network.
Once you reload, your system uses the configuration file you have directed it to use.
|
|