GNS3

GNS3 is networking simulator IDE. It's implemented by python and have a nice gui interface.

ubuntu repo has a old version(0.8), it's too old. It's latest version is 1.3.7, we want to install the latest version.

refer to this to install:

http://www.computingforgeeks.com/2015/03/easiest-way-to-install-gns3-130-on.html

http://blog.youkuaiyun.com/xlh1991/article/details/9157891

http://www.qingsword.com/

http://www.firstdigest.com/

http://srijit.com/category/networking/

http://computernetworkingnotes.com/subnetting-supernetting-and-vlsm/subnetting.html

https://www.informit.com/library/content.aspx?b=CCNP_Studies_Routing&seqNum=21

http://commonerrors.blogspot.com/