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ayanoa - juliane (juliane at )

[1] bind the /dev/net/tun in the uml ?



Cisco workshop Tuesday83 memo for beginner (me)

  • to connect to the Cisco router console (written con or painted in light blue :-) )
    • HW rollover cable + serial port
    • software "serial program" like minicom, cutecom ... (or hyperterminal in w$)

comment : it was easier to borrow a converter usb-serial than to launch an old machine with a serial port. so I used my laptop

  • software

you configure minicom with

  • $ minicom -s

=> choose device /dev/ttyUSB0 - and the settings for cisco : 9600 bauds - 8bits - no parity - no control flow [ help menu with minicom : CTRL A Z ]

  • Cisco router password recovery

you need to break the normal sequence of boot and enter in ROMmon (Rom monitor) : you have to press CTRL + BREAK on your keyboard just after powering the cisco, but with a laptop it was CTRL+FN+BREAK and it doesn't work (at least with mine)

fortunately in minicom you have "Send a break : F " so I just press F when I put on power on cisco

then you change the register to bypass the config file (startup-config file with all the password and stuff) ROMmon > confreg 0x2142

and you reset or power off/on the router

It reboots without configuration, when asking, don't enter in setup mode : answer no.

  • >

you type enable and you are in privileged (admin) mode without password. "normal way" : you copy the startup-config to the running config, in mode global config you change the password (sometimes you have several passwords to change : privileged console, vty access ....let's not discuss this) you copy the changed running config to startup config you change the register in configuration mode so the next boot it'll follow the usual sequence and read a startup-config file ROUTER #conf t ROUTER(config)# config-register 0x2102

but here it was easier - we have to erase the old startup-config for confidentiality reason so (in a mode ?) ROUTER# delete nvram:startup-config => ask confirmation and no more startup-config, but a default minimal one packed somewhere in ROM )

REMINDER ** REMINDER **REMINDER ** REMINDER **REMINDER ** REMINDER ** kernel workshop LinuxKernelWorkshop

  • langage C
    • jeter un coup d'oeil sur le programme "serial test" com.c [2]


debootstrap [3] [4]

memo liens vers schemas sympas : [5], [6]