CraSSH 2.03

Input files

The -s option allows you to feed in a switch file, i.e. a list of devices to connect to, the format is simple, one device per line, (either IP addresses or resolvable names is fine) eg:

192.168.1.72
coreswitch.domain.local
accessswitch1.domain.local

The -c option allows you to run multiple commands, for example:

show ver
show log

You can even make config changes:

conf t
interface GigabitEthernet1/9
description *** UNUSED ***

If you want to mix config commands with show commands then you need to include _*exits*_, e.g:

show run int g1/9
conf t
interface GigabitEthernet1/9
description *** UNUSED ***
exit
exit
show run int g1/9

Authentication

By default crassh will prompt for username and password credentials; -U can be used to supply a username as a CLI option, -P can be used to supply a password. Please take note that -P may expose your password in the command line history

crassh will look for and read a ~/.crasshrc file; currently the file supports two colon separated variables username and passwrd:

username: nick
password: mysecretpass

_STORING YOUR PASSWORD IN PLAIN TEXT IN `~/.crasshrc` IS A SECURITY RISK_ Please appropriately secure your system; crassh will perform a basic file permission check.

The -A option can be used to specify different authentication files, for example -A /var/secrets/router_credentials.txt

Do no Harm

crassh has a very basic safe mode, i.e. to stop users reloading all their switches on the network at once; if that is something you really _really_ want to do then -X is what you need!

Print Vs Write

By default, crassh will write it’s output to a file, in the format hostname-YearMonthDate-HourMinuteSecond. If you suppy the -p option, crassh will output to screen instead. If you want to Print and Write, use -pw

Execution Timeout

Let’s say you run a command that take a long time, say a million pings, crassh will wait for 60 seconds for the command to complete and then bail and move on to the next command - this should be fine for most commands. If you do actually want to send a million pings, then use the -t option to extend the timeout ( i.e how long crassh will wait )

Paramiko on Linux

For debian/ubuntu boxes

sudo apt-get install python-paramiko

For redhat/fedora boxes

sudo yum install python-paramiko

Paramiko on OS X

For apples, get homebrew setup and then

brew install python pip install paramiko

Paramiko on Windows

For windohz boxes, it’s a bit more complicated.

• Download and install Visual Studio C++ 2008 Express Edition ( do not install SQL )

• Install Python 2.7.8 – Select the correct MSI for your architecture

• Download get-pip.py ( Don’t use Internet Explorer it will mangle the file; _use Firefox_ to download. )

• Open an Administrator command prompt and run “c:Python27python.exe get-pip.py“

• From the same admin prompt, run “C:Program FilesMicrosoft Visual Studio 9.0Common7Toolsvsvars32.bat” ( that’s for 32bit machines… or for 64bit machines, run “C:Program Files (x86)Microsoft Visual Studio 9.0Common7Toolsvsvars64.bat“)

• From the same admin prompt, run “c:Python27Scriptspip install paramiko“

Disclaimer

The word Cisco is used as a description because this script should work with any Cisco IOS device. Cisco is a registered trademark of Cisco Systems Inc; this script is not associated, endorsed, supported or affiliated in any way with Cisco and none of these are implied.