1 Introduction

1.1 Goals

1.2 Notes

2 Exercises

3 Connect to your PC using ssh

4 Become root, and install the Subversion Version Control System:

In addition to Subversion we will specify to install telnet and the mutt email client. Both these package may already be installed from prior exercises. If so, don't worry - the apt-get command will not reinstall them.

$ sudo -s
# apt-get install subversion telnet mutt

5 Install Rancid itself

# apt-get install rancid

6 Add an alias for the rancid user in /etc/aliases file

# editor /etc/aliases
rancid-routers:         sysadm
rancid-admin-routers:   sysadm

Save the file, then run:

# newaliases

7 Edit /etc/rancid/rancid.conf

# editor /etc/rancid/rancid.conf

Find these lines in rancid.conf:

# list of rancid groups
#LIST_OF_GROUPS="sl joebobisp"; export LIST_OF_GROUPS

And, underneath them add the following line:

LIST_OF_GROUPS="routers"

(with no '#' at the front of line, and aligned to the left)

Find the line with CVSROOT:

CVSROOT=$BASEDIR/CVS; export CVSROOT

And, change it to:

CVSROOT=$BASEDIR/svn; export CVSROOT

Note the lowercase "svn".

We want to use Subversion for our Version Control System, and not CVS, so find the line with the parameter RCSSYS:

RCSSYS=cvs; export RCSSYS

And, change it to:

RCSSYS=svn; export RCSSYS

Now exit and save the file.

8 Change to the rancid user

9 CRITICAL! CRITICAL! CRITICAL!

10 CRITICAL! CRITICAL! CRITICAL!

11 CRITICAL! CRITICAL! CRITICAL!

Pay very close attention to what userid you are using during the rest of these exercises. If you are not sure simply type "id" on the command line at any time.

From a root prompt ("#"), switch identity to become the 'rancid' user:

# su -s /bin/bash rancid

Check that you ARE the rancid user:

$ id

You should see something similar (numbers may be different):

        uid=104(rancid) gid=109(rancid) groups=109(rancid)

12 IF YOU ARE NOT USER RANCID NOW, do NOT continue

13 Create /var/lib/rancid/.cloginrc

$ editor /var/lib/rancid/.cloginrc

Add the following two lines to the file:

add user *.ws.nsrc.org cisco
add password *.ws.nsrc.org nsrc+ws nsrc+ws

(The first 'cisco' is the username, the first and second 'nsrc+ws' are the password and enable password used to login to your router. The star in the name means that it will try to use this username and password for all routers whose names end .ws.nsrc.org)

Exit and save the file.

Now protect this file so that it cannot be read by other users:

$ chmod 600 /var/lib/rancid/.cloginrc

14 8. Test login to the router of your group

Login to your router with clogin. You might have to type yes to the first warning, but should not need to enter a password, this should be automatic.

$ /var/lib/rancid/bin/clogin rtrX.ws.nsrc.org

(replace X with your group number. So, group 1 is rtr1.ws.nsrc.org)

You should get something like:

      spawn ssh -c 3des -x -l cisco rtrX.ws.nsrc.org
       The authenticity of host 'rtrX.ws.nsrc.org (10.10.X.254)' can't be established.
       RSA key fingerprint is 73:f3:f0:e8:78:ab:49:1c:d9:5d:49:01:a4:e1:2a:83.
       Are you sure you want to continue connecting (yes/no)? 
       Host rtrX.ws.nsrc.org added to the list of known hosts.
       yes
       Warning: Permanently added 'rtrX.ws.nsrc.org' (RSA) to the list of known hosts.
       Password: 

       rtrX>enable
       Password: 
       rtrX#

Exit the from the router login:

       rtrX#exit

15 Initialize the SVN repository for rancid:

Make sure you are the rancid user before doing this:

    $ id

If you do not see something like

uid=108(rancid) gid=113(rancid) groups=113(rancid)"

then DO NOT CONTINUE until you have become the rancid user. See exercise 6 for details.

Now initialize the Version Control repository (it will use Subversion):

        $ /usr/lib/rancid/bin/rancid-cvs

You should see something similar to this:

    Committed revision 1.
    Checked out revision 1.
    At revision 1.
    A         configs
    Adding         configs

    Committed revision 2.
    A         router.db
    Adding         router.db
    Transmitting file data .
    Committed revision 3.

16 Do this ONLY if you have problems

If this does not work, then either you are missing the subversion package, or something was not properly configured during the previous steps. You should verify that subversion is installed and then before running the rancid-cvs command again do the following:

    $ exit
    # apt-get install subversion
    # su -s /bin/bash rancid
    $ cd /var/lib/rancid
    $ rm -rf routers
    $ rm -rf svn

Now try running the rancid-cvs command again:

    $ /usr/lib/rancid/bin/rancid-cvs

17 Create the router.db file

        $ editor /var/lib/rancid/routers/router.db

Add this line (NO spaces at the beginning please):

rtrX.ws.nsrc.org:cisco:up

(remember to replace X as appropriate)

Exit and save the file.

18 Let's run rancid!

       $ /usr/lib/rancid/bin/rancid-run

This may take some time so be patient.

Run it again, since the first time it might not commit correctly:

        $ /usr/lib/rancid/bin/rancid-run

19 Check the rancid log files:

        $ cd /var/lib/rancid/logs
        $ ls -l

... View the contents of the file(s):

        $ less routers.*

NOTE! Using "less" - to see the next file press ":n". To see the Previous file press ":p". To exit from less press "q".

20 Look at the configs

        $ cd /var/lib/rancid/routers/configs
        $ less rtrX.ws.nsrc.org

Where you should replace "X" with your group number.

If all went well, you can see the config of the router.

21 Let's change an interface Description on the router

        $ /usr/lib/rancid/bin/clogin rtrX.ws.nsrc.org

Where you should replace "X" with your group number.

At the "rtrX#" prompt, enter the command:

        rtrX# conf term

You should see:

        Enter configuration commands, one per line.  End with CNTL/Z.
        rtrX(config)#

Enter:

        rtrX(config)# interface LoopbackXX      (replace XX with your PC no)

You should get this prompt:

        rtrX(config-if)#

Enter:

        rtr2(config-if)# description <put your name here>
        rtr2(config-if)# end

You should now have this prompt:

        rtrX#

To save the config to memory:

        rtrX# write memory

You should see:

        Building configuration...
        [OK]

To exit type:

        rtrX# exit
Now you should be back at your rancid user prompt on your system:

22 Let's run rancid again:

        $ /usr/lib/rancid/bin/rancid-run

Look at the ranicd logs

        $ ls /var/lib/rancid/logs/

You should see the latest rancid execution as a new log file with the date and time in the name.

23 Let's see the differences

        $ cd /var/lib/rancid/routers/configs
        $ ls -l

You should see the router config file for your group:

        $ svn log rtrX.ws.nsrc.org

(where X is the number of your router)

Notice the revisions. You should see different no's such as r5 and r7. Choose the lowest and the highest one.

Let's view the difference between two versions:

        $ svn diff -r 5:7 rtrX.ws.nsrc.org | less
        $ svn diff -r 6:7 rtrX.ws.nsrc.org | less

... can you find your changes?

Notice that svn is the Subversion Version Control system command line tool for viewing Subversion repositories of information. If you type:

        $ ls -lah

You will see a hidden directory called ".svn" - this actually contains all the information about the changes between router configurations from each time you run rancid using /usr/lib/rancid/bin/rancid-run.

Whatever you do, don't edit or touch the .svn directory by hand!

24 Check your mail

Now we will exit from the rancid user shell and the root user shell to go back to being the "sysadm" user. Then we'll use the "mutt" email client to see if rancid has been sending emails to the sysadm user.

        $ exit                  (takes your from rancid to root user)
        # exit                  (take you from root to sysadm user)
        $ id
        ... check that you are now the 'sysadm' user again;
        
        ... if not, log out and in again as sysadm to your virtual host
        
        $ mutt

(When asked to create the Mail directory, say Yes)

If everything goes as planned, you should be able to read the mails sent by Rancid. You can select an email sent by "rancid@pcX.ws.nsrc.org" and see what it looks like.

Notice that it is your router description and any differences from the last time it was obtained using the rancid-run command.

Now exit from mutt.

(use 'q' return to mail index, and 'q' again to quit mutt)

25 Let's make rancid run automatically every 30 minutes from using cron

cron is a system available in Linux to automate the running of jobs. First we need to become the root user again:

        $ sudo -s

Now we will create a new job to run for the rancid user:

        # crontab -e -u rancid

It will ask you for your favorite editor. Select whichever editor you have been using in class.

Add this line at the bottom of the file (COPY and PASTE):

        */30  *  *  *  *  /usr/lib/rancid/bin/rancid-run

... then save and quit from the file.

That's it. The command "rancid-run" will execute automatically from now on every 30 minutes all the time (every day, week and month).

26 Now add all the other routers

Note the hostnames for the routers

rtrX.ws.nsrc.org where X goes from 1 to 9

If you have less routers in your class, then only include the actual, available routers.

Become the rancid user and update the router.db file:

        # su -s /bin/bash rancid
        $ editor /var/lib/rancid/routers/router.db

Add the other classroom routers to the file. You should end up with something like (COPY and PASTE):

rtr1.ws.nsrc.org:cisco:up
rtr2.ws.nsrc.org:cisco:up
rtr3.ws.nsrc.org:cisco:up
rtr4.ws.nsrc.org:cisco:up
rtr5.ws.nsrc.org:cisco:up
rtr6.ws.nsrc.org:cisco:up
rtr7.ws.nsrc.org:cisco:up
rtr8.ws.nsrc.org:cisco:up
rtr9.ws.nsrc.org:cisco:up

(Note that "cisco" means this is Cisco equipment -- it tells Rancid that we are expecting to talk to a Cisco device here. You can also talk to Juniper, HP, ...).

Be sure the entries are aligned to the left of the file.

27 Run rancid again:

        $ /usr/lib/rancid/bin/rancid-run

This should take a minute or more now, be patient.

28 Check out the logs:

        $ cd /var/lib/rancid/logs
        $ ls -l

... Pick the latest file and view it

        $ less routers.YYYYMMDD.HHMMSS

This should be the last file listed in the output from "ls -l"

You should notice a bunch of statements indicating that routers have been added to the Subversion version control repository, and much more.

29 Look at the configs

        $ cd /var/lib/rancid/routers/configs
        $ more *.ws.nsrc.org

Press the SPACE bar to continue through each file. Or, you could do:

    $ less *.ws.nsrc.org

And press the SPACE bar to scroll through each file and then press ":n" to view the next file. Remember, in both cases you can press "q" to quit at any time.

If all went well, you can see the configs of ALL routers

30 Run RANCID again just in case someone changed some configuration on the router

        $ /usr/lib/rancid/bin/rancid-run

This could take a few moments, so be patient....

31 Play with clogin:

        $  /usr/lib/rancid/bin/clogin -c "show clock" rtrX.ws.nsrc.org

Where "X" is the number of your group.

What do you notice ?

Even better, we can show the power of using a simple script to make changes to multiple devices quickly:

        $ editor /tmp/newuser

... in this file, add the following commands (COPY and PASTE):

configure terminal
username NewUser secret 0 NewPassword
exit
write

Save the file, exit, and run the following commands from the command line:

    $ for r in 1 2 3 4
    
    Your prompt will now change to be ">". Continue by typing:
    
    > do
    > /var/lib/rancid/bin/clogin -x /tmp/newuser rtr$r.ws.nsrc.org
    > done

Now your prompt will go back to "$" and rancid clogin command will run and execute the commands you just typed above on routers rtr1, rtr2, rtr3 and rtr4. This is simple shell scripting in Linux, but it's very powerful.

Q. How would you verify that this has executed correctly ? Hint: "show run | inc"

A. Connect to rtr1, rtr2, rtr3 and rtr4. Type "enable" and then type "show run | inc username" to verify that the NewUser username now exists. Type exit to leave each router. Naturally you could automate this like we just did above.

32 Add the RANCID SVN (Subversion) repository in to WebSVN

If you are still logged in as user rancid, get back to root. Remember you can type "id" to check what userid you are.

        $ exit
        # 

Install WebSVN:

        # apt-get install websvn

During the installation, follow the following instructions.

              /var/lib/rancid/svn

Select and press ENTER. Do the same when asked about "svn repositories" on the next screen. That is, use the path:

              /var/lib/rancid/svn

and not what is shown by default. Select and press ENTER.

Select for the next screen talking about permissions and press ENTER.

Note: if you are installing under Ubuntu 14.04, you may get an error about the conf.d directory not being present. If so, workaround the problem like this (including creating a dummy conf.d directory):

# ln -s /etc/websvn/apache.conf /etc/apache2/conf-available/websvn.conf
# mkdir /etc/apache2/conf.d
# a2enconf websvn.conf
# service apache2 reload

33 Fix permissions. The web server must be able to read the SVN (Subversion) folder

        # chgrp -R www-data /var/lib/rancid/svn
        # chmod g+w -R /var/lib/rancid/svn

34 Browse the rancid files from your Web browser!

    http://pcX.ws.nsrc.org/websvn

Browse the files under the 'routers/configs' directory. You can see all your router configuration files here.

35 Review revisions

WebSVN lets you see easily the changes between versions.

This will show you the differences between two separate router configurations.

WebSVN is a convenient way to quickly see differences via a GUI between mulitple configuration files. Note, this is a potential security hole so you should limit access to the URL http://host/websvn using passwords (and SSL) or appropriate access control lists.

36 Optional: Fetching configs with a non-privileged rancid user

In a production environment, we'd probably want to add a "rancid" user on the devices, without config privileges, but able to retrieve do a show running-config.

One way to do this, add a user in config mode:

rtrX# conf term
Enter configuration commands, one per line.  End with CNTL/Z.
rtrX(config)# username rancid privilege 4 secret password
rtrX(config)# privilege exec level 4 show running-config view full

This creates a rancid user with privilege level 4. On the next line, we allow that user to execute show running-config

You also need to add the username and password to your .cloginrc

add user *.ws.nsrc.org rancid
+add password *.ws.nsrc.org password
add autoenable *.ws.nsrc.org 1

The autoenable means the user will be in the right privilege level immediately after login and no enable is needed to run show running-config

Note: try and look at the clogin manpage to find out how you can specify another user (for example: cisco) when using clogin interactively, to make changes with -c or -x (as shown above).

See more at: http://www.toms-blog.com/backup-cisco-config-with-rancid-and-an-un-priviledged-user/

37 On the use of hostnames in RANCID vs. IP Addresses

(Note: it is also allowed to use IP addresses, and one could also write:

       add user 10.10.* cisco
       add password 10.10.* nsrc+ws nsrc+ws
       add user rtr*.ws.nsrc.org cisco
       add password rtr*.ws.nsrc.org nsrc+ws nsrc+ws