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Write to NV memory. |
write memory |
This command writes the device's configuration in to the Non-Volatile RAM (NVRAM) on the boot flash. Use this command in privileged EXEC mode. |
Router# write memory |
A BFD flap is triggered when one of the following configuration elements are activated or deactivated and configuration is saved to memory:
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Changing the configuration register value. |
config-register value |
The router has a 16-bit configuration register in NVRAM. Each bit has value 1 (on or set) or value 0 (off or clear), and each bit setting affects the router behavior upon the next reload power cycle. Use this command in Global configuration mode. |
Router(config)# config-register 0xvalue |
Potential enough to flap bfd. |
Copy running configuration to startup configuration. |
copy running-config startup-config |
This command copies running configuration to startup configuration. |
Router# copy running-config startup-config |
A BFD flap is not triggered for all 'write mem' commands. For instance, when the configuration attributes changes without either a write or an erase+write on the NVRAM, the BFD is not triggered. In the following example, when one of the configuration elements are activated/deactivated and the configuration is saved using the 'write mem' command, the flap is triggered:
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Changing boot variables. |
boot { bootstrap | config | host | netowrk | system } |
This command configures bootstrap image file, configuration file, router specific config file, Networkwide config file or system image file. |
Router(config)# boot bootstrap |
Potential enough to flap bfd. |
Setting the system software clock manually. |
clock set hh:mm:ss day month year |
To manually set the system software clock, use one of the formats of the clock set command in privileged EXEC mode. clock set hh:mm:ss day month year clock set hh:mm:ss month day year |
Router# clock set 13:32:00 23 July 1997 |
Potential enough to flap bfd. Note Every time the command is issued. |
Random Entropy |
No special Command exists for this. |
After the system boot up, entropy is collected by accessing the security chip. This is potential enough to flap the BFD session immediately after the router boots up. |
No command |
Potential enough to flap bfd. |
Crashing the router on user’s wish. |
test crash |
This is a hidden Cisco IOS command to crash the Cisco router on a user’s wish. |
Router# test crash |
Potential enough to flap bfd. |
License EULA |
license accept end user agreement |
To accept the End-user License Agreement (EULA) for all Cisco IOS software packages and features at one time. |
Router(config)#l icense accept end user agreement |
Potential enough to flap bfd. |
RTC Battery Failure |
No CLI |
Write the event of losing battery for Real Time Clock. |
No CLI |
Potential enough to flap bfd. |
Erasing NV memory. |
erase nvram |
This command erases the nvram: file system. |
Router# erase nvram: |
Potential enough to flap bfd. |
Erasing startup-config |
erase startup-config |
This command erases startup configurations. |
Router# erase startup-config |
Potential enough to flap bfd. |
Erasing NV memory. |
write erase |
This command erases the NV memory. |
Router# write erase |
Potential enough to flap bfd. |
Writing configuration to memory. |
write |
This command quickly saves config to memory. |
Router# write |
Potential enough to flap bfd. |
Reloading the router. |
reload |
This command reloads the router. The reload time is written to NV memory. |
Router# reload |
Potential enough to flap bfd. |
Enabling warm rebooting. |
warm-reboot count value uptime value |
Enables a router to warm-reboot. |
Router(config)# warm-reboot count 10 uptime 10 |
Potential enough to flap bfd. |
New software license boot. |
license boot module module-name level license-level |
To boot a new software license on routing platforms, use the license boot module command in global configuration mode. |
Router(config)# license boot module c2900 technology-package datak9 |
Potential enough to flap bfd. |
Enabling or disabling USB ports. |
config mode : hw-module usb |
Enable or disable USB ports from IOS config mode. |
Router(config)# hw-module usb disable Router(config)# no hw-module usb disable |
Will trigger a BFD flap. |
Disabling access to ROMMON. |
[no] service password-recovery |
This command disables all access to ROMMON. |
Router# no service password-recovery |
Potential enough to flap bfd. |