Configure Cisco routers to save core dumps

If you do, you must be prepared in memory of important information to know why the router to router crashed and save it to prevent future accidents. To do this, you must configure the router to the core dump information in the case of an accident to save.

Let’s see what a hole, as it can help and how to configure the router to store these important files for analysis.

What is a memory dump?

A dump is simply a full copy of the image memory of the router. If the router has a system error or error can not be prosecuted, so it supports all of its memory and writes the contents of memory on a server before it is recharged.

It is very important to keep a copy of the discharge to avoid possible causes of the accident. During the discharge can not be read by you, is readable and useful to the Technical Assistance Center for Cisco (TAC). When an accident occurs on the router, open a TAC case with people who are trained to have to read this issue.

Note that the dump from the router at the time of the accident must be saved. A dump can only be taken after the accident happened and the router is restarted.

Orders big problems when a router crashes
Before showing how to configure core dumps, look at some commands that are important to troubleshooting router crashes:

show version: This command displays such things as the hardware configuration of the router, the version of IOS software image, memory and interfaces are available. Perhaps only a piece of faulty hardware. This information could also help to see what version of code running on the router and the amount of flash memory is available.

Show stacks: This is another very useful command that monitors the use of cellular processes and interrupt routines. This command displays information such as a bus error or a software forced crash.

show the context: This command stores information like the reason for the restart and monitoring of information in the stack.

Besides a core dump, the Cisco TAC may ask you to stop the script technology to support the program. This command displays all parameters, statistics and connect to the router.

For more information about these commands, see the Cisco documentation “Troubleshooting Router accidents.”

How can I configure the Cisco IOS software to save core dumps?
The Cisco IOS save or transfer a core dump file using four different methods. They are:
File Transfer Protocol (FTP)
Remote Copy Protocol (RCP)
Trivial Transfer Protocol (TFTP)
Flash Disk (stored in the router, are not transmitted over the network)

The recommended method is through File Transfer Protocol (FTP) is what I want to give the context. Mentioned in the act, if CPR is used FTP, or one of the forms, ensure that each protocol is working properly before discharge. In other words, the test of a transfer of a species with this method.

For example, you could FTP by copying the router configuration in the same FTP server, configuring the kernel is used to test:
Router # copy running-config ftp
To manually create a backup without having to reload, enter the following command in privileged mode:
Router # write core
This is useful if the router is just malfunctioning but not crashing. Note that all memory is dumped, not just what is in use, so make sure you have enough memory to accept it. In addition, it is not recommended in a production environment, a router, in use.

These are the commands to use for a memory dump using FTP:
ip ftp username username: Configures the username for FTP connections.
ip ftp password: Configures the password for the FTP connection.
except ftp:Configures protocol, FTP core dump.
Except for the region size of 65536: Sets the size of the region.
Exception dump IP address: Set the IP address of the router sends the core dump in case of accident.

Cisco recommends that you connect to FTP server router directly, without intermediate hops.

Health debug command is also a good control of errors in debugging memory usage, including memory I / O This is likely to work with the representative of Cisco technology. Here is an excerpt from the output of the show version command is for a core dump. Please note the error in the bottom of the descent.
Router # show version Cisco Internetwork Operating System IOS ™ RSP Software (RSP-PV-M), Version 12.0 (10.6) ST, beginning MAINTENANCE INTERIM SOFTWARE INSTALLATION Copyright (c) 1986-2000 Cisco Systems, Inc. Compiled Fri 23 4:02 p.m.-Jun-00 imaging richv text-base: 0x60010908, data base: 0x60D96000 ROM: System startup, Version 12.0 (19990806:174725) SOFTWARE DEVELOPMENT bootflash: RSP Software (RSP-BOOT-M), Version 12.0 (9), the availability of early deployment software router (FC1) is 20 hours, 56 minutes System returned to ROM error – a Software forced crash 0x60287EE8 PC file system image “Slot0: rsp-PV-120- MZ .. 10.6 ST ”
Another issue that could be useful in case of accident is the crash info file. It is stored in bootflash or flash memory. For more details on crash information, see the Cisco documentation “Retrieving File Information accident.”

It is important that the type of configuration a core dump on each router, so you can capture the memory dump if your router ever crashes. Once the router is restarted, if was not recorded, the core dump crash can not be recovered. In this way, I hope you are able to use the dump using the Cisco TAC to resolve the problem of the crash reaches the first router address.

For more information on accidents, creating core dumps and troubleshooting router “, router blocks interference.” You see the Cisco articles “Creating Core Dumps”