CISCO CLASS:
1. Login as adminstrator
2. View class curriculum
3. Click on index and find labs:
   2.2.2, 2.2.3.2, 6.2.5
4. Finish 2.2.2 first.
5. For 2.2.3.2 and 6.2.5, please 
   refer to "download" folder and
   enter the respective 
   configuration to each router.
 Example: lab-a.txt for router A

config terminal  (global)
show version   (information)
show controller serial 0 (cable)
show running-config ()
show interface serial 1 (up,up)
exit    (up one level)
end     (back to root)
Ctrl-Z  (same as end)
no shutdown
ping xxx.xxx.xxx.xxx