Cisco Router 860, 880 Series User Manual
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B-11 Book Title OL-xxxxx-xx Appendix B Concepts Access Lists Access Lists With basic standard and static extended access lists, you can approximate session filtering by using the established keyword with the permit command. The established keyword filters TCP packets based on whether the ACK or RST bits are set. (Set ACK or RST bits indicate that the packet is not the first in the session and the packet therefore belongs to an established session.) This filter criterion would be part of an...
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C-1 Book Title OL-xxxxx-xx APPENDIXC ROM Monitor The ROM monitor firmware runs when the router is powered up or reset. The firmware helps to initialize the processor hardware and boot the operating system software. You can use the ROM monitor to perform certain configuration tasks, such as recovering a lost password or downloading software over the console port. If there is no Cisco IOS software image loaded on the router, the ROM monitor runs the router. This appendix contains the following...
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C-2 Book Title OL-xxxxx-xx Appendix C ROM Monitor ROM Monitor Commands TimesaverBreak (system interrupt) is always enabled for 60 seconds after the router reboots, regardless of whether it is set to on or off in the configuration register. During this 60-second window, you can break to the ROM monitor prompt by pressing the Break key. ROM Monitor Commands Enter ? or help at the ROM monitor prompt to display a list of available commands and options, as follows: rommon 1 > ?alias set and...
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C-3 Book Title OL-xxxxx-xx Appendix C ROM Monitor Command Descriptions Commands are case sensitive. You can halt any command by pressing the Break key on a terminal. If you are using a PC, most terminal emulation programs halt a command when you press the Ctrl and the Break keys at the same time. If you are using another type of terminal emulator or terminal emulation software, see the documentation for that product for information on how to send a Break command. Command Descriptions Ta b l...
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C-4 Book Title OL-xxxxx-xx Appendix C ROM Monitor Disaster Recovery with TFTP Download TFTP Download Command Variables This section describes the system variables that can be set in ROM monitor mode and that are used during the TFTP download process. There are both required variables and optional variables. NoteThe commands described in this section are case sensitive and must be entered exactly as shown. Required Variables These variables must be set with these commands before you use the...
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C-5 Book Title OL-xxxxx-xx Appendix C ROM Monitor Disaster Recovery with TFTP Download Optional Variables These variables can be set with these commands before using the tftpdnld command: Using the TFTP Download Command To download a file through TFTP perform these steps in ROM monitor mode Step 1Use the appropriate commands to enter all the required variables and any optional variables described in preceding sections. Step 2Enter the tftpdnld command as follows: rommon 1 > tftpdnld -r...
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C-6 Book Title OL-xxxxx-xx Appendix C ROM Monitor Configuration Register You will see output similar to the following: IP_ADDRESS: 10.3.6.7 IP_SUBNET_MASK: 255.255.0.0DEFAULT_GATEWAY: 10.3.0.1 TFTP_SERVER: 192.168.254.254 TFTP_FILE: c880-advsecurityk9-mzDo you wish to continue? y/n: [n]: Step 3If you are sure that you want to continue, enter y in response to the question in the output: Do you wish to continue? y/n: [n]:y The router begins to download the new file. If you mistakenly entered...
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C-7 Book Title OL-xxxxx-xx Appendix C ROM Monitor Console Download The following display shows an example of entering the confreg command: rommon 7> confreg Configuration Summary enabled are: console baud: 9600boot: the ROM Monitor do you wish to change the configuration? y/n [n]: yenable “diagnostic mode”? y/n [n]: y enable “use net in IP bcast address”? y/n [n]: enable “load rom after netboot fails”? y/n [n]: enable “use all zero broadcast”? y/n [n]: enable...
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C-8 Book Title OL-xxxxx-xx Appendix C ROM Monitor Debug Commands Command Description The following are the syntax and descriptions for the xmodem console download command: xmodem [-cyrx] destination_file_name Follow these steps to run Xmodem: Step 1Move the image file to the local drive where Xmodem will execute. Step 2Enter the xmodem command. Error Reporting Because the ROM monitor console download uses the console to perform the data transfer, when an error occurs during a data transfer,...